Final Exam Q Flashcards
1.Morphology of the skin and mucous membrane. Characteristics and functional significance of each layer.
The morphology of the skin and mucous membranes includes several layers:
—Skin:
1. Epidermis: The outermost layer, providing a waterproof barrier and creating our skin tone.
2. Dermis: Beneath the epidermis, containing tough connective tissue, hair follicles, and sweat glands.
3. Hypodermis: Deeper tissue made of fat and connective tissue that houses larger blood vessels and nerves. It provides insulation and padding.
Mucous Membranes:
- Found lining body cavities and internal passages, such as the nose, mouth, lungs, and digestive tract. They secrete mucus, which keeps the membranes moist and protects against infection.
—Functional Significance:
- Epidermis protects against external pathogens.
- Dermis supports skin flexibility and strength.
- Hypodermis acts as an insulator and shock absorber.
- Skin appendages. The structure of the sebaceous glands: varieties, functions.
Skin appendages include hair, nails, sweat glands, and sebaceous glands, each with specific functions.
Sebaceous Glands Structure and Functions:
- These are microscopic exocrine glands in the skin that secrete an oily or waxy substance called sebum, this coats and lubricates hair and skin.
- They are most often associated with hair follicles, discharging sebum into the follicular duct and onto the surface.
- Found everywhere except palms and soles.
Varieties of Sebaceous Glands:
1. Holocrine Sebaceous Glands: Common type, found throughout most of the body.
2. Specialized Sebaceous Glands: Such as Meibomian glands in the eyelids and others in the genital area.
Functions:
- Sebum moisturizes and waterproofs the skin and hair.
- Antimicrobial properties help inhibit the growth of certain bacteria on the skin.
- Acts as a barrier against external contaminants.
- Skin appendages. The structure of the sudoriferous (sweat) glands: varieties, functions.
Structure of Sudoriferous Glands:
- Eccrine Glands: The most numerous type, found all over the skin, especially on palms, soles, and forehead. They are coiled tubular glands that open directly onto the skin surface.
- Apocrine Glands: Found in specific areas like the armpits, groin, and around the nipples. They are larger than eccrine glands, and their ducts open into hair follicles.
Functions:
- Eccrine Sweat Glands: Secrete a clear, odorless fluid, primarily composed of water and salt. They help to cool the body through evaporation and regulate body temperature.
- Apocrine Sweat Glands: Produce a thicker fluid that creates body odor when decomposed by bacteria.
- Skin appendages. The structure of the hair follicle. General characteristics of hair types. Hair types and age characteristics of their growth.
Hair is another essential skin appendage, and hair follicles are the structures from which hair grows.
Structure of the Hair Follicle:
- Each follicle is a tubular sheath surrounding the lower part of the hair shaft, and is embedded within the skin.
- The follicle has several layers, with an outer dermal root sheath and an inner epithelial root sheath.
- The base of the follicle forms a bulb where hair originates in the dermis, adjoining the hair papilla filled with tiny blood vessels (capillaries) for nourishment.
General Characteristics of Hair Types:
1. Lanugo Hair: Fine, soft, usually unpigmented hair that covers the fetus and is usually shed before birth.
2. Vellus Hair: Thin, short, and lightly pigmented hair found on most of the body.
3. Terminal Hair: Longer, coarser, and usually more pigmented hair that develops with puberty due to hormonal changes; found on the scalp, eyebrows, legs, arms, and genital regions.
Hair Types and Age Characteristics of Their Growth:
- Infancy: Babies are born with soft, fine vellus hair and some lanugo, which is usually shed within a few weeks or months and replaced by vellus hair.
- Childhood: Most hair remains vellus until puberty.
- Puberty and Adult Age: Hormonal changes trigger the growth of terminal hair in areas such as the pubic region, under the arms, on the face for men, and on the limbs for both sexes.
- Aging: With age, some terminal hair may revert back to vellus hair, leading to thinning hair or baldness in some adults, particularly men.
- Skin appendages. The structure of the nail plate.
The nail plate is part of the nail system, which is an integral component of the skin appendages.
Structure of the Nail Plate:
- Keratin: The nail plate is composed mainly of keratin, which is a tough, protective protein. This gives nails their strength and resilience.
- Layers: It consists of several layers of dead, tightly packed cells.
- Free Edge: The part of the nail plate that extends beyond the finger or toe.
- Body: The main and visible part of the nail plate.
- Root: The part of the nail plate that is under the cuticle, embedded within the skin.
- Nail Bed: The skin beneath the nail plate.
- Lunula: The crescent-shaped whitish area of the bed of the nail. The lunula represents the visible part of the nail matrix, or root, where new nail growth occurs.
Functions:
- Protection: Nails protect the tips of fingers and toes from mechanical damage.
- Sensory Aid: They enhance fine-touch perception and manipulation of tiny objects.
- Support: Nails add rigidity to the ends of digits, aiding in their function.
- Skin functions; neuro-receptor, thermoregulatory, secretory-excretory, respiratory, resorptive, protective, immunological, pigment-forming.
The skin is a complex organ with several vital functions that contribute to the overall homeostasis and well-being of the body. Here is an outline of the key functions of the skin:
1. Neuro-receptor Function: The skin contains a vast network of nerve endings and receptors that detect touch, pressure, vibration, temperature, and pain sensations.
2. Thermoregulatory Function: The skin helps maintain body temperature through sweat production and the dilation or constriction of blood vessels. Eccrine sweat glands secrete sweat that evaporates from the skin surface, cooling the body.
3. Secretory-Excretory Function: The skin secretes sebum from sebaceous glands, which helps keep the skin and hair moisturized. It also excretes waste products like salts and small amounts of metabolic waste, alongside sweat.
4. Respiratory Function: While not a primary organ of respiration, the skin can absorb oxygen and expel carbon dioxide to a very small degree.
5. Resorptive Function: The skin can absorb substances from the environment, such as medications in transdermal patches, or harmful agents, highlighting the need for protective clothing and skin products.
6. Protective Function: The skin provides a physical barrier against mechanical injury, pathogenic organisms, and harmful radiation. The stratum corneum, the outermost layer, is critical in this barrier.
7. Immunological Function: Langerhans cells in the skin are part of the immune system and help detect and fight off pathogens. The skin acts as a first line of defense in the body’s immune response.
8. Pigment-forming Function: Melanocytes in the skin produce melanin, a pigment that protects against ultraviolet radiation damage and gives skin its color. Variations in melanin production are responsible for the wide variety of human skin tones.
- Primary morphological elements. Definition, characteristics, evolutionary paths, clinical examples: spot, papule, pustule, blister
- Spot (Macule):
- Definition: A macule is a flat, distinct area of skin that is visibly different in color from the surrounding skin and is not raised or depressed relative to the skin surface. It’s typically less than 1 cm in diameter.
- Characteristics: The key characteristic of a macule is its color change, which could be red, brown, white, etc., without any alteration in texture or thickness of the skin. - Papule:
- Definition: A papule is a small, raised, solid bump less than 1 cm in diameter on the skin. It emerges above the surface of the surrounding skin without producing any visible fluid.
- Characteristics: It can be due to alterations in skin color or texture and may come in various shapes (round, oval) and colors (red, brown). - Pustule:
- Definition: A pustule is a small, circumscribed, superficial skin elevation that is filled with purulent material (pus).
- Characteristics: They can form as a result of infection, inflammation, or follicular reactions and usually indicate an infectious or inflammatory condition. - Blister (Vesicle/Bulla):
- Definition: A blister represents a fluid-filled elevation of skin. A vesicle is smaller than 1 cm and filled with clear fluid, whereas a bulla is larger than 1 cm.
- Primary morphological elements. Definition, characteristics, evolutionary paths, clinical examples: tubercle, node, vesicle, bulla.
- Tubercle:
- Definition: A tubercle is a solid, rounded nodule greater than 0.5 cm in diameter, but generally smaller than 2 cm. It can extend into the dermis or subcutaneous tissue.
- Characteristics: Tubercles may vary in color but are typically characterized by their elevation above the skin surface and can be felt as a firm lump.
- Clinical Examples: Tuberculosis cutis, leprosy, syphilis, and some types of lipomas. - Node (Nodule):
- Definition: A node or nodule is similar to a tubercle but is larger—typically greater than 2 cm in diameter. It extends deeper into the dermis and even into the subcutaneous tissue.
- Characteristics: Nodes are larger and firmer than papules. They can be seen in various shapes and can affect deeper layers of the skin compared to papules and tubercles.
- Clinical Examples: Cystic acne, erythema nodosum, rheumatoid nodules, and lipomas. - Vesicle:
- Definition: A vesicle is a small, fluid-filled lesion (with clear serum) that is less than 1 cm in diameter. It arises from the outermost skin layer, the epidermis
- Clinical Examples: Chickenpox, herpes simplex, contact dermatitis, and allergic eczema. - Bulla:
- Definition: A bulla is a larger fluid-filled lesion than a vesicle, measuring more than 1cm in diameter.
- Characteristics: Bullae can contain serum, blood, or pus, and they tend to form from a separation in the deep epidermal layers or between the epidermis and the dermis.
- Clinical Examples: Blistering disorders like pemphigus vulgaris, bullous pemphigoid, large blisters from burns, and drug reactions
- Secondary morphological elements. Definition, characteristics, evolutionary paths, clinical examples: secondary spot, squama (scale), crust.
- Secondary Spot:
- Definition: A secondary spot (also known as a macule) is an area of altered color or texture that remains after an initial primary skin lesion has resolved. Unlike the primary spot, it’s often a result of healing processes.
- Characteristics: These can include changes in pigmentation like hyperpigmentation or hypopigmentation and may vary in size.
- Clinical Examples: Post-inflammatory hyperpigmentation or hypopigmentation after conditions like acne or eczema have healed. - Squama (Scale):
- Definition: A squama, or scale, is a flake of dead epidermal cells that is abnormal in size, shape, or texture.
- Characteristics: Scales can be fine and powdery, or they can be thick and adherent; they vary in size and in how easily they can be detached.
- Clinical Examples: Psoriasis (silvery scales), tinea pedis (athlete’s foot, flaky skin), and seborrheic dermatitis (dandruff). - Crust:
- Definition: A crust, or scab, forms when serum, pus, or blood dries out on the skin surface.
- Characteristics: Crusts can range in color from yellow to brown to greenish-black, depending on their composition. They are typically seen on top of a break in the skin.
- Clinical Examples: Impetigo (honey-colored crusts), scabs on abrasions or cuts, and the crusts following the rupture of herpes simplex blisters.
- Secondary morphological elements. Definition, characteristies, evolutionary paths, clinical examples: erosion, ulcer
Secondary morphological elements also encompass disruptions to the integrity of the skin surface, which are the result of factors such as the progression of a primary lesion, trauma, or infection. Erosion and ulcer are two such types of secondary lesions:
1. Erosion:
- Definition: An erosion is a loss of part or all of the epidermis (the skin’s outer layer) that occurs following the rupture of a vesicle or bulla, or due to trauma.
- Characteristics: Erosions are shallow depressions on the skin that are moist and do not bleed. They heal without scarring because they do not extend into the dermis.
- Evolutionary Paths: Erosions will typically heal by re-epithelialization, in which the skin cells migrate to close the wound. If they extend deeper, however, they may become ulcers.
- Clinical Examples: Ruptured chickenpox vesicles, abrasions, or areas of skin maceration.
2. Ulcer:
- Definition: An ulcer is a deeper loss of skin tissue that involves the epidermis and at least part of the dermis. It may extend down to subcutaneous tissue and muscle.
- Characteristics: Ulcers often have more clearly defined edges than erosions and may be painful. They frequently discharge pus or other fluids and are prone to bleeding. Because they extend deeper into the skin, they can heal with scarring.
- Evolutionary Paths: Healing of ulcers can be slow and typically involves granulation (formation of new tissue) and re-epithelialization. Large or chronic ulcers may require medical intervention to promote healing.
- Clinical Examples: Venous stasis ulcers on the lower legs, diabetic foot ulcers, and pressure ulcers (bedsores).
- Secondary morphological elements. Definition, characteristics, evolutionary paths, clinical examples: abrasion, fissure.
—In dermatology, secondary morphological elements arise from the modification or evolution of primary lesions. They might result from natural disease progression, healing, external trauma, or other pathological processes:
1. Abrasion:
- Definition: An abrasion is a superficial wound to the skin caused by friction or scraping that results in the loss of at least part of the epidermis.
- Characteristics: Abrasions are often raw and tender to the touch, may weep serous fluid, and usually have irregular borders. The base of an abrasion is often pink and moist.
- Evolutionary Paths: They heal by re-epithelialization, where new skin cells proliferate and migrate over the area. Abrasions typically heal without scarring unless they become infected or are very deep.
- Clinical Examples: Road rash from falls, scratches from rough surfaces, or skin injuries from athletic activities.
2. Fissure:
- Definition: A fissure is a linear loss of epidermis and dermis due to exaggerated skin tension or decreased skin elasticity.
- Characteristics: Fissures are characterized by sharply defined, nearly vertical walls that can be painful, especially if they are deep. They may bleed if the fissure extends into the capillaries.
- Evolutionary Paths: Healing occurs by slow granulation and epithelial bridge formation. If the skin is continually stressed or dry, fissures may persist or worsen.
- Clinical Examples: Cheilitis (fissures in the lips), athlete’s foot where the skin cracks between the toes, and anal fissures from constipation or inflammatory bowel disease.
- Secondary morphological elements. Definition, characteristics, evolutionary paths, clinical examples of scar, cicatricial atrophy.
-When talking about the body’s healing process, especially the skin, secondary morphological elements like scars and cicatricial atrophy are significant indicators of the skin’s history and the processes it has undergone following injury or disease.
1. Scar:
- Definition: A scar is a mark left on the skin or within body tissue where a wound, burn, or sore has not healed completely and fibrous connective tissue has developed.
- Characteristics: Scars may appear flat, lumpy, sunken, or colored and can vary significantly in their texture compared to surrounding skin. Initially, scars may be red or purple, becoming paler over time, and are generally non-painful.
- Clinical Examples: Surgical incisions, injuries that have penetrated through the dermis, healed wounds from acne or chickenpox, and healed areas of skin loss due to infection like a staphylococcal scalded skin syndrome.
2. Cicatricial Atrophy:
- Definition: Cicatricial atrophy refers to the skin’s appearance when there is a loss of tissue and the surrounding skin contracts, often following a destructive skin process or injury.
- Characteristics: The skin appears thin, flattened, and more translucent than normal. It may adhere more directly to underlying bone or muscle and often shows the signs of previous scarring processes.
- Clinical Examples: Skin damage from lupus, long-standing venous ulcers that have healed, and areas of skin recovery following severe acne or burns.
- Secondary morphological elements. Definition, characteristics, Evolutionary paths, clinical examples, lichenification, vegetation.
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Lichenification:
- Definition: Lichenification is the thickening of the skin with accentuation of normal skin markings that arises due to chronic rubbing or scratching.
- Characteristics: The skin appears leathery and rough with exaggerated skin lines and often has a variable degree of pigmentation. It is usually associated with itching.
- Clinical Examples: Common in chronic atopic dermatitis or eczema, and areas exposed to repeated mechanical trauma, like the ankles in chronic venous insufficiency or the back of the neck in patients who frequently rub that area. -
Vegetation:
- Definition: Vegetation refers to the pathological growth of tissue resulting in elevated plaques that are often broad at the base and exophytic (growing outward from the surface).
- Characteristics: These lesions can look wart-like or cauliflower-like in appearance, with irregular or pebbly surfaces, which can be soft or firm and are typically secondary to chronic inflammation or infection.
- Clinical Examples: Seen in immunocompromised patients like those with HPV-induced verrucous carcinoma or inflammatory diseases leading to hypertrophic granulation tissue.
- Pathohistological changes in the epidermis: hyperkeratosis, parakeratosis, acanthosis, granulosis, dyskeratosis, acantholysis. Characteristics, clinical examples.
- Hyperkeratosis:
- Characteristics: Thickening of the stratum corneum, often associated with an abnormality in the skin’s keratinization process.
- Clinical Examples: Calluses from friction, psoriasis where excessive skin cell production leads to thick scale, and actinic keratosis from sun damage. - Parakeratosis:
- Characteristics: Retention of the nuclei in the stratum corneum where normally the cells are anucleated, which indicates an abnormal keratinization process.
- Clinical Examples: Psoriasis and zinc deficiency (acrodermatitis enteropathica). - Acanthosis:
- Characteristics: Thickening of the stratum spinosum layer of the skin, which can be diffuse or focal.
- Clinical Examples: Acanthosis nigricans, which is associated with insulin resistance, and epidermal nevus. - Granulosis:
- Characteristics: Hypergranulosis is an increased granular layer thickness, while hypogranulosis means a thinner or absent layer.
- Clinical Examples: Lichen planus typically shows hypergranulosis and wart virus infection shows granular layer changes. - Dyskeratosis:
- Characteristics: Abnormal keratinization occurring prematurely within individual cells or groups of cells below the stratum corneum.
- Clinical Examples: Disorders like Darier disease and actinic keratosis. - Acantholysis:
- Characteristics: Loss of intercellular connections resulting in the breakdown of cellular cohesion within the epidermis.
- Clinical Examples: Pemphigus vulgaris where autoantibodies attack desmogleins, the proteins that hold skin cells together, causing blistering and sores.
- Pathohistological changes in the epidermis. Types of serous inflammation in the epidermis: vacuolar, ballooning degeneration, spongiosis. Characteristics, clinical examples.
Vacuolar Degeneration (Interface Dermatitis):
- Characteristics: Damage at the dermoepidermal junction, where there is the formation of vacuoles (small cavities) around the basal keratinocytes.
- Clinical Examples: Lupus erythematosus and lichen planus can show vacuolar alteration.
Ballooning Degeneration:
- Characteristics: Characterized by keratinocytes swelling (ballooning), becoming large, pale, and roundish with eventual cell rupture.
- Clinical Examples: Viral infections such as herpes simplex and varicella-zoster virus exhibit this change.
Spongiosis:
- Characteristics: Inter-cellular edema in the epidermis leading to widened intercellular spaces and a spongy appearance of the skin.
- Clinical Examples: Commonly seen in acute eczema, contact dermatitis, and atopic dermatitis.
- Pathomorphological and histological changes in the dermis: acute and chronic inflammation, dermal edoma, papillomatosis, infectious granuloma.
Acute Inflammation:
- Characteristics: A rapid response to injury or infection characterized by the presence of edema and infiltration by neutrophils.
- Clinical Examples: Acute cellulitis or an acute flare of a chronic condition like psoriasis or eczema.
Chronic Inflammation:
- Characteristics: Long-standing inflammation characterized by lymphocytes, plasma cells, macrophages, and sometimes eosinophils and granuloma formation.
- Clinical Examples: Conditions like lupus erythematosus, scleroderma, and chronic dermatitis of various kinds.
Dermal Edema:
- Characteristics: Accumulation of fluid in the dermal interstitial tissue.
- Clinical Examples: Urticaria (hives) where there’s transient dermal edema along with dilated lymphatics.
Papillomatosis:
- Characteristics: Enlargement of the dermal papillae projecting above the skin surface that causes a rough texture.
- Clinical Examples: Seen in conditions such as verruca vulgaris (warts) where there is epithelial hyperplasia.
Infectious Granuloma:
- Characteristics: A type of chronic inflammation where there’s a formation of granulomas, which are small nodules of immune cells.
- Clinical Examples: Tuberculosis of the skin, leprosy, and deep fungal infections can result in granuloma formation.
- Methods of examination of the skin and mucous membranes in dermatology (dermatological tests in the diagnosis of certain skin diseases and diseases of the oral mucosa (psoriasis, lichen planus, pemphigus, tuberculosis, neurodermatitis, lupus crythematosus, etc.).
Physical Examination:
- Initial assessment through visual inspection and palpation of the skin and mucous membranes.
Dermoscopy:
- Non-invasive technique that uses magnification and lighting to evaluate pigmented skin lesions, particularly useful in diagnosing melanoma.
Patch Testing:
- Used to identify substances that a person is allergic to and can cause contact dermatitis.
KOH Preparation:
- A test where potassium hydroxide is used to dissolve skin cells, leaving fungal cells visible under a microscope, often used in fungal infections.
Tzanck Smear:
- A test that involves scraping the base of a blister to look for signs of certain blistering diseases like herpes simplex and varicella-zoster.
Biopsy:
- Involves taking a small sample of tissue for microscopic examination. Can be incisional, excisional, or a shave biopsy.
Wood’s Lamp Examination:
- Ultraviolet light used to highlight changes in the skin invisible to the naked eye, useful for diagnosing conditions like vitiligo or fungal infections.
Blood Tests:
- Includes complete blood count, autoimmune disease panels, antinuclear antibody tests, and other specific tests depending on the suspected condition.
Culture and Sensitivity:
- Identifying microbes causing infection and their antibiotic sensitivities, especially in cases of bacterial, fungal, or viral skin infections.
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Psoriasis:
- Typically diagnosed by the physical presentation, a biopsy may be performed to confirm the diagnosis in uncertain cases.
Lichen Planus:
- Diagnosis usually through clinical presentation and history, but a biopsy with direct immunofluorescence can be helpful to confirm unclear cases.
Pemphigus:
- Direct immunofluorescence or Tzanck smear can be used for diagnosing, alongside a biopsy.
Cutaneous Tuberculosis:
- Skin biopsy along with staining (acid-fast bacillus stain), culture, or PCR testing for Mycobacterium tuberculosis
Neurodermatitis:
- Diagnosed clinically, but a skin biopsy might be performed to rule out other conditions.
Lupus Erythematosus:
- A combination of clinical presentation, blood tests for autoantibodies (ANA, anti-dsDNA), complement levels, and a skin biopsy with immunofluorescence is typically employed.
19, Fundamentals of dermatosestherapy. General and local therapy. Keratoplastic agents in the external treatment of dermatoses, Mechanism of action, indications, method of application.
—-General Therapy:
- This includes systemic treatments such as oral medications, injections, or infusions that affect the entire body.
- Examples include antibiotics for bacterial infections, antifungals for fungal infections, biologic therapies for psoriasis, and oral corticosteroids for severe inflammatory conditions.
——–Local Therapy:
- Topical treatments applied directly to the skin.
- Examples include corticosteroid creams for inflammation, antifungal creams, moisturizers for dry skin conditions, and topical chemotherapy agents for certain skin cancers.
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Keratoplastic Agents:
- These are topical agents that regulate keratinization and are used to treat skin conditions characterized by abnormal skin growth, scaling, or roughness.
- They work by modulating the process of keratinization, which helps to normalize the shedding of the stratum corneum, the outermost layer of the skin.
Mechanism of Action:
- Keratoplastic agents act by promoting the proliferation of basal epidermal cells or by modulating the cohesiveness of the corneocyte layer, often increasing the shedding of dead skin cells and smoothing the skin surface.
- Some agents have anti-inflammatory properties or can modulate the immune response.
Indications:
- Conditions characterized by hyperkeratosis such as psoriasis, ichthyosis, and keratosis pilaris.
- Disorders featuring abnormal desquamation like acne and seborrheic dermatitis.
Method of Application:
- Keratoplastic agents are typically applied topically in various formulations like creams, ointments, gels, lotions, or shampoos.
- The specific concentration and formulation, frequency of application, and duration of therapy depend on the problem being treated, the agent being used, and the individual patient’s response.
—Examples of keratoplastic agents include:
- Salicylic Acid
- Urea:
- Alpha-hydroxy Acids
- Fundamentals of dermatosestherapy. General and local therapy. General concepts of PUVA therapy.
General Therapy:
- This includes systemic treatments such as oral medications, injections, or infusions that affect the entire body.
- Examples include antibiotics for bacterial infections, antifungals for fungal infections, biologic therapies for psoriasis, and oral corticosteroids for severe inflammatory conditions.
Local Therapy:
- Topical treatments applied directly to the skin.
- Examples include corticosteroid creams for inflammation, antifungal creams, moisturizers for dry skin conditions, and topical chemotherapy agents for certain skin cancers.
PUVA (Psoralen + UVA):
- Psoralen is a photosensitizing agent that makes the skin more sensitive to ultraviolet light. It can be administered orally, topically, or even added to bathwater.
- UVA light penetrates deeper into the skin compared to UVB and, when used with psoralen, it can effectively treat certain skin disorders.
Mechanism of Action:
- Psoralen interacts with DNA when exposed to UVA light, which leads to an alteration in skin cell growth and a decrease in inflammation.
Indications:
- PUVA therapy is commonly indicated for conditions such as psoriasis, vitiligo, mycosis fungoides (a type of cutaneous T-cell lymphoma), and eczema.
- It is also used for other less common disorders that are responsive to phototherapy.
Procedure:
- For oral PUVA, patients ingest psoralen before UVA exposure, usually about 2 hours prior to the treatment.
- In bath or topical PUVA, the skin is soaked or covered with psoralen before UVA light exposure.
- Fundamentals of dermatosestherapy. General and local therapy. External dosage forms: lotions, pastes, ointments, creams, powders, lotion, emulsion. Definition. Method of application based on indications.
Lotions:
- Definition: Lotions are liquid preparations often prescribed for treating large or hairy areas of the body because they are easy to spread and less greasy.
- Application: They are typically applied with a cotton ball or pad, or directly with the hands, and are suitable for conditions like eczema or heat rash where a cooling, soothing effect is desired.
Pastes:
- Definition: Pastes are semi-solid preparations that contain a larger proportion of solid material, which makes them thicker and more absorbent than creams or ointments.
- Application: They are applied in a thin layer and are often used for their protective and absorbing properties in conditions like diaper rash or in areas where skin surfaces rub together.
Ointments:
- Definition: Ointments are thick, greasy formulations that are good for delivering active ingredients to the skin and are often used to treat dry, scaly skin conditions.
- Application: They are best applied in a thin layer to affected areas and are especially useful for bedtime application in conditions such as psoriasis or chronic eczema.
Creams:
- Definition: Creams are emulsions that are less greasy than ointments and can be absorbed quickly. They are usually favored for daytime use.
- Application: Applied by gently rubbing into the skin, they are effective for a wide range of conditions, including mild to moderate eczema and dermatitis.
Powders:
- Definition: Powders consist of fine particles and are used to reduce friction and absorb moisture.
- Application: They are dusted onto the skin and are often used in areas prone to moisture such as the feet, groin, and underarms, helping conditions like athlete’s foot and intertrigo.
Gel:
- Definition: Gels are typically alcohol-based, which allows them to dry quickly when applied to the skin. They are clear and non-greasy.
- Application: Applied in a thin layer, they are useful for hairy areas or on the scalp, and in conditions like acne or sunburn.
Emulsions:
- Definition: Emulsions are mixtures of oil and water that can be used as a base for creams or lotions.
- Application: The method of application would be similar to creams or lotions and can be suitable for conditions where both moisturizing and a cooling effect are desired.
- Pyoderma: Definition and classification.
—Classification of Pyoderma:
The classification of pyoderma generally takes into account the depth and severity of the infection. Here is a simplified classification:
1-Primary Pyoderma:
- Impetigo: Highly contagious, superficial skin infection often seen in children. It is characterized by honey-colored crusts on the face and extremities.
- Folliculitis: Infection of hair follicles, presenting as small, red, and sometimes painful bumps, often with a pus-filled top.
- Ecthyma: A more severe form of impetigo that penetrates deeper into the dermis, forming ulcers with a crust on top.
- Cellulitis: A diffuse inflammation of the skin that involves the deeper dermis and subcutaneous fat with areas of redness, swelling, and tenderness.
2-Secondary Pyoderma:
- Infection that occurs on top of a pre-existing skin condition such as atopic dermatitis, scabies, or wounds, which have been compromised and become infected.
————Classification by severity or course of the disease:
- Acute Pyoderma: Occurs suddenly and typically responds well to treatment.
- Chronic Pyoderma: Persistent and may be more difficult to treat, often due to antibiotic resistance or underlying conditions that compromise the skin, such as diabete
- Staphyloderma: acute and chronic forms (ostiofolliculitis, sycosis, furuncle, carbuncle, hydradenitis, etc.). Etiology, methods of diagnosis and treatment. Prevention methods in patients of different age groups.
—Staphyloderma refers to skin infections caused by Staphylococcus bacteria, particularly Staphylococcus aureus. These infections can be acute or chronic and range in severity from mild to potentially life-threatening. Here are descriptions of the conditions listed as well as the etiology, diagnostics, treatments, and prevention methods:
### Acute Forms:
Ostiofolliculitis:
- Definition: Infection of the hair follicle opening, presenting as small, pus-filled lesions.
- Etiology: Often due to Staphylococcus aureus infection.
- Diagnosis: Usually diagnosed based on clinical appearance; cultures may be taken if recurrent.
- Treatment: Topical antibacterial agents; good hygiene.
- Prevention: Regular washing with antibacterial soap; avoiding sharing personal items.
Sycosis:
- Definition: Deep infection of the hair follicles, often in the beard area, leading to pustules and abscesses.
- Etiology: Caused primarily by Staphylococcus aureus.
- Diagnosis: Clinical assessment; sometimes cultures are needed.
- Treatment: Topical and oral antibiotics.
- Prevention: Proper shaving techniques, skin cleansing.
Furuncle:
- Definition: Deep infection of a single hair follicle, creating a boil.
- Etiology: Most often caused by Staphylococcus aureus, entering through minor skin abrasions.
- Diagnosis: Clinical; may require incision and drainage, with cultures from the pus.
- Treatment: Warm compresses, incision and drainage if necessary, antibiotics.
- Prevention: Skin hygiene, avoiding manipulation of lesions.
Carbuncle:
- Definition: Larger, deeper infection than a furuncle involving a group of hair follicles.
- Etiology: Staphylococcus aureus infections.
- Diagnosis: Based on clinical signs; may require imaging to assess depth.
- Treatment: Incision and drainage, antibiotics.
- Prevention: As with furuncles, good skin hygiene and avoiding injury/abrasion to skin.
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### Chronic Forms:
Hydradenitis Suppurativa:
- Definition: A chronic condition involving the inflammation of sweat glands, leading to painful, deep abscesses and scars, commonly in the armpits and groin.
- Etiology: Linked to blockage of hair follicles and secondary infection, often with Staphylococcus aureus, stress, hormonal factors, and smoking may exacerbate the condition.
- Diagnosis: Clinical diagnosis; may need imaging to evaluate the extent.
- Treatment: Antibiotics for infection, anti-inflammatory medication, surgery in severe cases.
- Prevention: Weight management, smoking cessation, loose-fitting clothing to decrease friction, good hygiene.
### Methods of Diagnosis and Treatment:
Etiology:
- These conditions are predominantly caused by infection with the bacterium Staphylococcus aureus, which can invade through small breaks in the skin.
Diagnosis:
- Clinical examination is often sufficient for diagnosis.
- Culture of pus or drainage to identify the specific bacteria and its antibiotic sensitivity.
- Occasionally, blood tests or imaging studies are needed, particularly for more severe infections.
Treatment:
- Hygiene measures and warm compresses to promote drainage.
- Topical antiseptics or antibiotics for milder infections.
- Oral antibiotics for more significant infections, based on culture results when available.
Appropriate antibiotics, including oral antibiotics cephalexin, clindamycin, amoxicillin/clavulanate
- Incision and drainage may be required for abscesses.
- In cases of recurrent staph infections, nasal carriers of Staphylococcus aureus might be treated.
Prevention Methods:
- Good personal hygiene and regular handwashing.
- Avoid sharing personal items such as towels and razors.
- Streptoderma: acute and chronic forms (impetigo: streptococcal, bullous, slit-like, lichen simplex, impetigo of nail folds; streptococcal diaper rash; ecthyma: ordinary, terebrant; chronic superficial diffuse streptoderma). Etiology, methods of diagnosis and treatment. Prevention methods in patients of different age groups.
### Acute Forms:
Impetigo (Streptococcal):
- Definition: A highly contagious skin infection commonly seen in children, with small blisters or crusty lesions.
- Etiology: Mainly caused by Streptococcus pyogenes and sometimes by Staphylococcus aureus.
- Diagnosis: Visual examination, and confirmation may be done through bacterial cultures.
- Treatment: Topical antibiotics or oral antibiotics in more widespread cases.
- Prevention: Good hygiene, prompt treatment of cuts and scrapes, and avoiding direct contact with infected persons.
Bullous Impetigo:
- Definition: A form of impetigo characterized by larger blisters.
- Etiology: Usually caused by a toxin-producing strain of Staphylococcus aureus.
- Diagnosis: Clinical appearance, culture of blister fluid may be tested to confirm.
- Treatment: Removal of blister roofs, topical therapy, or oral antibiotics.
- Prevention: Similar to non-bullous impetigo; personal hygiene and avoiding sharing personal items.
Ecthyma:
- Definition: A more severe, ulcerated form of impetigo that extends to the dermis.
- Etiology: Caused by Streptococcus pyogenes, sometimes in combination with Staphylococcus aureus.
- Diagnosis: Based on the clinical presentation; cultures may be needed.
- Treatment: Oral antibiotics, appropriate wound care.
- Prevention: As with impetigo, maintaining good skin hygiene.
————————–
### Chronic Forms:
Lichen Simplex:
- Definition: A skin condition due to chronic itching and scratching that leads to thickened skin.
- Etiology: Often secondary to conditions that cause itchiness, including bacterial infections.
- Diagnosis: Clinical evaluation, ruling out underlying infections.
- Treatment: Reduction of scratching, topical corticosteroids, treating any underlying infection.
- Prevention: Managing chronic conditions that lead to scratching, maintaining skin moisture.
Chronic Superficial Diffuse Streptoderma:
- Definition: A persistent infection of the skin by Streptococcus bacteria.
- Etiology: Chronic skin conditions that allow bacterial infiltration and growth.
- Diagnosis: Clinical signs and bacterial cultures.
- Treatment: Long-term antibiotics; treatment of underlying skin issues.
- Prevention: Controlling conditions such as eczema prevents skin breaches allowing bacterial entry. Regular follow-up with a dermatologist is suggested.
### Methods of Diagnosis and Treatment:
Etiology:
- Caused by streptococcal bacteria, predominantly Streptococcus pyogenes, and may coexist with Staphylococcus infections.
Diagnosis:
- Usually diagnosed from the clinical presentation.
- Bacterial cultures can identify the pathogen and help guide antibiotic therapy.
- For complicated cases, a skin biopsy might be indicated.
Treatment:
- Good wound care and hygiene.
- Topical antibacterial treatments for localized infection.
- Oral antibiotics for more extensive disease.
- In persistent or recurrent cases, a search for potential nasal carriers or environmental reservoirs.
Prevention Methods:
- Encouraging frequent handwashing, especially in children.
- Keeping fingernails short to minimize the risk of skin breakdown due to scratching.
- Avoiding close contact with those infected and not sharing personal items like towels
- Strepto-staphyloderma: acute and chronic forms. Etiology, methods of diagnosis and treatment. Prevention methods in patients of different age groups.
### Etiology:
- The cause is generally a co-infection with Streptococcus pyogenes and Staphylococcus aureus, which leads to a variety of skin lesions.
### Acute Forms:
- Manifest as quickly developing skin conditions, such as impetigo, wound infections, cellulitis, or abscesses.
### Chronic Forms:
- Chronic presentations can occur due to inadequate treatment, recurring exposure to the pathogens, or underlying comorbidities that compromise the immune system.
### Methods of Diagnosis:
- Clinical Examination: The appearance of the skin lesions gives a primary indication of infection.
- Microbial Cultures: Swabs from the lesions can help identify the specific bacteria causing the infection.
- Sensitivity Testing: Determines the appropriate antibiotics to combat the specific bacteria found in cultures.
- Blood Tests: May be done if systemic infection is suspected.
### Treatment:
Medications for such mixed infections might include:
- Penicillins: For example, Dicloxacillin may be used as it is effective against certain strains of both Staphylococcus and Streptococcus.
- Cephalosporins: Cephalexin (Keflex) can be an alternative if the sensitivity profile is appropriate.
- Clindamycin: Offers coverage against both types of bacteria and can be used in cases of allergies to other antibiotics.
- Combination Therapy: Sometimes, especially with resistant bacteria, a combination of drugs like a beta-lactam antibiotic with a macrolide may be effective.
The choice of medication should be guided by the result of sensitivity tests and clinical judgment.
### Prevention Methods:
- Hygiene: Regular handwashing and good skin care are fundamental.
- Scabies: etiology, epidemiology, clinical picture, diagnostics, differential diagnosties, principles and methods of treatment, prevention.
—-Scabies is an itchy skin condition caused by a tiny burrowing mite called Sarcoptes scabiei. Here are the details regarding its etiology, epidemiology, clinical picture, and more.
### Etiology:
- Caused by infestation with the mite Sarcoptes scabiei var. hominis.
### Epidemiology:
- Scabies is common worldwide and affects people of all races and social classes.
- Spread is usually by direct, prolonged skin-to-skin contact with an infested person and is common in crowded environments.
### Clinical Picture:
- Presents with intense itching, especially at night.
- Characteristic burrows in the webbing between fingers, on the wrists, elbows, buttocks, and genital area.
- Secondary infections due to scratching are common.
### Diagnostics:
- Diagnosis is primarily clinical, based on the appearance of burrows or the distribution of the rash and the itching pattern.
- Microscopic examination of skin scrapings can confirm the presence of mites, eggs, or fecal matter (scybala).
- Dermoscopy may also help visualize mites in burrows.
### Differential Diagnoses:
- Includes atopic dermatitis, other ectoparasites like body lice, drug reactions, and more.
### Treatment:
Medications typically used include:
Topical Treatments:
- Permethrin Cream (5%): The first-line treatment for scabies. Applied to the whole body from the neck down and washed off after 8–14 hours.
- Crotamiton Cream or Lotion: An alternative that also has anti-pruritic properties.
- Lindane: Less commonly used due to neurotoxicity risks, especially in children and pregnant women.
- Ivermectin Lotion: Recently approved topical form for treatment of head lice and scabies.
Oral Treatments:
- Ivermectin: Used in cases where topical treatments are ineffective or not feasible. Dosage is typically determined by body weight.
Supportive Treatments:
- Antihistamines: To help with itching.
- Antibiotics: If secondary bacterial skin infection occurs.
### Prevention:
- Good personal hygiene and prompt treatment of infected individuals and their close contacts.
- Washing clothing, bedding, and towels in hot water and drying them on a hot cycle or sealing them in a bag for at least 72 hours to kill mites.
- Pediculosis: etiology, epidemiology, clinical picturo, diagnostics, differential diagnostics, principles and methods of treatment, prevention.
Pediculosis refers to an infestation with lice, parasitic insects that feed on human blood. There are three types of lice that infest humans: head lice (Pediculus humanus capitis), body lice (Pediculus humanus corporis), and pubic lice (‘crabs’), or Pthirus pubis.
### Etiology:
- Infestations occur from direct contact with an infested person or through contact with infested personal items.
### Epidemiology:
- Common worldwide and seen in all socioeconomic groups, often in crowded settings.
- Head lice infestations are especially common among school children aged 3-11 years.
### Clinical Picture:
- Head Lice: Signs include itching of the scalp, red bites, and possibly a rash from scratching. Lice and nits (eggs) may be seen on the hair shafts.
- Body Lice: More associated with social distress and signs may include itching, rash, and long-term infestations can lead to thickened and darkened skin, especially around the waist, groin, and upper thighs.
- Pubic Lice: Presents with itching in the genital area, with visible lice or nits on pubic hair.
### Diagnostics:
- Visual inspection for nits, nymphs, or adult lice is common.
- Wet combing can be used to catch lice on the comb.
- For pubic lice, a magnifying glass may be necessary due to their smaller size.
### Differential Diagnostics:
- Dandruff, hair casts, folliculitis, eczema, or scabies should be considered.
### Treatment:
The following medications are used to treat lice infestations:
Topical Treatments:
- Permethrin Lotion/Cream (1% for head lice, 5% for body lice): Applied to affected areas and left on for a specified amount of time before rinsing off.
- Malathion Lotion (0.5%): Applied to the hair, left to dry naturally, and washed off after 8-12 hours.
- Pyrethrins with Piperonyl Butoxide: Applied to the hair and washed off after 10 minutes.
- Benzyl Alcohol Lotion: Applied to the hair and washed off after 10 minutes. It asphyxiates lice but doesn’t kill eggs, so repeat treatment is usually necessary.
- Ivermectin Lotion: Applied to dry hair and rinsed off after 10 minutes.
Oral Treatments:
- Oral Ivermectin: Given twice, 7-10 days apart, when topical therapy is unsuccessful.
Removal Methods:
- Manual removal of nits with a fine-toothed nit comb is important for the successful elimination of head lice.
### Prevention:
- Avoiding close head-to-head contact.
- Classification of mycoses. Pathogens. Epidemiology of skin mycoses.
Classification of Mycoses:
1. Superficial Mycoses:
- These are limited to the outermost layers of the skin and hair.
- Pathogens include: Malassezia species; causes conditions like pityriasis versicolor.
2. Cutaneous Mycoses:
- These affect the skin, hair, and nails, and are caused primarily by dermatophytes.
- Pathogens include:
- Trichophyton spp.
- Conditions include ringworm (tinea), athlete’s foot (tinea pedis), and nail fungus (onychomycosis).
3. Subcutaneous Mycoses:
- These involve the deeper layers of the skin up to the subcutaneous tissue.
- Pathogens include:
- Sporothrix schenckii causing sporotrichosis.
4. Systemic Mycoses:
- These can affect any part of the body and are typically acquired via inhalation.
- Pathogens include:
- Histoplasma capsulatum causing histoplasmosis.
- Coccidioides spp. causing coccidioidomycosis.
- Blastomyces dermatitidis causing blastomycosis.
5. Opportunistic Mycoses:
- These occur primarily in people with weakened immune systems.
- Pathogens include:
- Candida spp. causing candidiasis.
- Aspergillus spp. causing aspergillosis.
- Cryptococcus neoformans causing cryptococcosis.
- Pneumocystis jirovecii causing pneumocystis pneumonia.
### Epidemiology of Skin Mycoses:
- Dermatophyte Infections (Dermatophytoses):
- These are among the most common skin mycoses globally.
- They are highly contagious and can spread through direct contact with infected individuals or animals, or indirectly through contaminated objects.
- Factors like humidity, high temperatures, and crowded living conditions can increase the risk of transmission.
- Candidiasis:
- It’s caused by Candida species, typically Candida albicans, although other species can also be responsible.
- These yeasts are normal flora in many individuals but can cause infection if the skin’s microbial environment is disrupted or the immune system is compromised.
- Risk factors include antibiotic use, diabetes, and conditions that affect skin integrity.
- Pityriasis Versicolor:
- Caused by Malassezia yeasts that normally reside on the skin surface.
- Overgrowth can occur due to changes in the skin environment, like increased oiliness or moisture, leading to patches of discolored and flaky skin.
- More common in warm, humid climates.
- Keratomycosis (pityriasis versicolor): etiology, pathogenesis, clinical picture,diagnostics, differential diagnosties, principles of treatment, prevention.
Keratomycosis, also known as pityriasis versicolor, is a common superficial fungal infection of the skin. Let’s break down your query into specific sections:
### Etiology:
Pityriasis versicolor is primarily caused by the yeast Malassezia, a genus of fungi that normally resides on the skin’s surface. The specific species involved include Malassezia globosa, Malassezia furfur, and others within this genus.
### Pathogenesis:
The pathogenesis of pityriasis versicolor involves an overgrowth of the Malassezia yeasts on the skin. Factors that can contribute to this overgrowth include:
- Warm and humid environments
- Excessive sweating
- Oily skin
- Immune system changes
- Hormonal variations
These yeasts produce azelaic acid and other substances that disrupt melanin synthesis, leading to either hyperpigmented or hypopigmented patches on the skin, which is characteristic of the condition.
### Clinical Picture:
The typical clinical presentation of pityriasis versicolor includes:
- Patches of skin that appear lighter or darker than the surrounding areas
- Fine scaling of the skin (flaking)
- Mild itching (pruritus), particularly in warm environments
- Most commonly affects the back, chest, neck, and upper arms
The color of the patches may range from white to pink or brown, depending on the individual’s skin tone and the extent of exposure to sunlight, as the affected areas often do not tan normally.
### Diagnostics:
Diagnosis of pityriasis versicolor primarily involves the clinical assessment and may include:
- Wood’s Lamp Examination: Under ultraviolet light, the patches may show a yellow to yellow-green fluorescence.
- KOH (Potassium Hydroxide) Preparation: Skin scrapings are examined microscopically after treatment with KOH to reveal the characteristic “spaghetti and meatballs” appearance of Malassezia cells and hyphae.
- Skin Biopsy: Rarely needed, but can be performed in atypical cases.
- Culture: Not typically performed due to the ubiquity of the Malassezia species on normal skin.
—Treatment of pityriasis versicolor typically involves topical antifungals like ketoconazole, selenium sulfide, or terbinafine.
- Denmatophytosis. Epidermophytosis of large folds: etiology, pathogenesis, clinical picture,
diagnostics, differential diagnostics, principles of treatment, prevention.
Dermatophytosis or Epidermophytosis, particularly of the large skin folds, is commonly referred to as Tinea cruris. It’s a type of fungal infection affecting the groin, inner thighs, and buttocks (large folds of the skin). Here’s a comprehensive overview:
### Etiology:
The most common causative fungi of tinea cruris are dermatophytes, which are mold-like fungi that feed on the keratin in skin:
- Trichophyton rubrum
- Trichophyton mentagrophytes
- Epidermophyton floccosum
### Pathogenesis:
Dermatophytes thrive in warm, moist environments. They invade the stratum corneum of the skin and proliferate, causing infection. The infection is more common in males and is often associated with:
- Sweat retention and friction
- Wearing tight clothing that does not allow the skin to breathe
- Hot, humid climates
- Obesity, which can create large skin folds prone to moisture accumulation
### Clinical Picture:
Clinical manifestations of tinea cruris include:
- Itching and burning in the groin, thigh skin folds, and buttocks
- A red, raised rash with a clear center, which may blister and ooze
- Changes in skin color
- Sharp borders, often more red around the edges
### Diagnostics:
Diagnosis usually involves clinical examination and can be confirmed by:
- KOH Exam: A microscopic examination of a skin scraping treated with KOH to identify the fungus.
- Fungal Culture: May be used to identify the exact species of dermatophyte.
### Differential Diagnostics:
Tinea cruris should be differentiated from other conditions like:
- Candidiasis
- Intertrigo
- Erythrasma
- Psoriasis
- Seborrheic dermatitis
- Inverse lichen planus
### Principles of Treatment:
Treatment generally involves:
- Topical antifungal agents like:
- Imidazoles: e.g., clotrimazole, ketoconazole, or miconazole
- Allylamines: e.g., terbinafine
- Azoles: e.g., econazole, oxiconazole, or sulconazole
### Prevention:
Preventive measures include:
- Maintaining proper hygiene
- Drying the groin area thoroughly after showering
- Dermatophylosis, Epidermophytosis of the feet: etiology, pathogenesis, clinical picture, diagnostics, differential diagnosties, principles of treatment, prevention.
Dermatophytosis of the feet, commonly known as Tinea pedis or athlete’s foot, is a fungal infection of the skin on the feet. Here’s a detailed insight:
### Etiology:
Tinea pedis is caused by several types of dermatophyte fungi, including:
- Trichophyton rubrum
- Trichophyton mentagrophytes
- Epidermophyton floccosum
### Pathogenesis:
The infection occurs when the dermatophytes invade the keratin layer of the epidermis. Conditions that favor the growth of these fungi include:
- Warm, moist environments like sweaty shoes
- Public showers or locker rooms where the infection can spread from person to person
- Occlusive footwear
- Minor skin or nail injuries
### Clinical Picture:
Clinical manifestations include:
- Itching, stinging, and burning between the toes or on the soles of the feet
- Peeling and cracking skin, especially between the toes and on the soles
- Dryness and scaling on the sides or bottoms of the feet
- Blisters and ulcers in severe cases
### Diagnostics:
Diagnosis is based on the clinical presentation and confirmed with laboratory tests like:
- KOH Exam: Skin scrapings examined under a microscope after being treated with potassium hydroxide reveal dermatophyte fungi.
- Fungal Culture: Identifies the species of the dermatophyte.
- Skin Biopsy with PAS Stain: Rarely necessary but used to rule out other conditions.
### Differential Diagnostics:
Differential diagnosis may include:
- Eczema
- Psoriasis
- Dyshidrosis
- Contact dermatitis
- Scabies
### Principles of Treatment:
Treatment typically involves:
- Topical antifungal medications are first-line treatments and include:
- Imidazole Creams: e.g., clotrimazole or miconazole
- Allylamines: e.g., terbinafine
- Azoles: e.g., ketoconazole
### Prevention:
Preventive tips include:
- Washing feet daily and drying thoroughly, especially between the toes
- Changing socks at least once a day or more often if sweating heavily
- Demnatophylosis Rubromycosis, Etiology, pathogenesis, clinical picture, diagnostics, differential diagnostics, principles of treatment, prevention.
Dermatophytosis, known when caused by Trichophyton rubrum as Rubromycosis, is a fungal infection affecting various parts of the body like the foot (tinea pedis), groin (tinea cruris), nails (onychomycosis), and other regions. Specific to T. rubrum, it results in chronic and often recalcitrant infections.
### Etiology:
Rubromycosis is caused by the dermatophyte fungus Trichophyton rubrum. This fungus is one of the most common dermatophytes responsible for a broad range of skin and nail infections.
### Pathogenesis:
T. rubrum can invade keratinized tissues, such as the stratum corneum of the skin, nails, and hair. It produces enzymes that degrade keratin, allowing the fungus to spread. Factors contributing to infection include:
- Warm, moist conditions
- Compromised immune system
- Minor skin trauma
- Genetic susceptibility
- Poor circulation
### Clinical Picture:
Clinical manifestations depend on the infection site and typically include:
- Tinea Pedis: Itchy, scaling skin between the toes or on the soles; may also have blisters.
- Tinea Cruris: Red-brown rash with sharp edges in the groin area.
- Onychomycosis: Thickened, discolored, and sometimes painful nails.
- Tinea Corporis: Ring-like red, itchy patches on the body.
- Tinea Manuum: Scaling on the palms and fingers.
### Diagnostics:
Diagnostic methods involve:
- Direct Microscopy with KOH: Skin scrapings or nail clippings are treated with potassium hydroxide to reveal fungal elements.
- Fungal Culture: Can confirm the diagnosis and identify the fungal species.
- Wood’s Lamp Examination: Not typically helpful for T. rubrum infections.
### Differential Diagnostics:
Conditions that might be confused with rubromycosis include:
- Eczema
- Psoriasis
### Principles of Treatment:
Treatment involves:
- Topical Antifungals: Especially for skin infections, including imidazoles (e.g., clotrimazole, ketoconazole) and allylamines (e.g., terbinafine).
- Oral Antifungals: Often necessary for nail infections and extensive skin involvement; medications include terbinafine, itraconazole, and fluconazole.
- Proper skin and nail care to reduce moisture and prevent reinfection.
### Prevention:
Preventive measures include:
- Maintaining good skin hygiene
- Keeping affected areas clean and dry
- Dermatophytosis. Microsporia (superficial and chronic, infiltrative-suppurative forms): pathogens, source, transmission routes, clinical picture, diagnostics, differential diagnostics,
principles of treatment, prevention.
Dermatophytosis, particularly when referred to as microsporia, is a fungal infection typically affecting the scalp or body with different forms, including superficial, chronic, and infiltrative-suppurative forms. Here is an overview:
### Pathogens:
- Microsporum canis
- Microsporum audouinii
- Microsporum gypseum
### Source:
- Infected animals (especially for M. canis)
- Infected individuals
- Fomites like clothing, brushes, and combs
- Contaminated soil
### Transmission Routes:
- Direct contact with infected persons or animals
- Indirect contact through fomites
- Contact with spores in the environment
### Clinical Picture:
- Superficial: scale and hair breakage
- Chronic: less inflammation, adults more often affected
- Infiltrative-suppurative: kerion formation with nodules and potential pus
### Diagnostics:
- Wood’s Lamp: can reveal fluorescence
- Microscopy with KOH: detects fungal spores/hyphae
- Culture: identifies specific pathogen
### Differential Diagnostics:
- Other dermatophytoses (e.g., tinea capitis)
- Seborrheic dermatitis
- Scalp psoriasis
- Bacterial folliculitis
- Alopecia areata
### Principles of Treatment:
For successful management of microsporia, the following treatments are usually applied:
#### Superficial Microsporia
- Topical Antifungals: such as
- Miconazole
- Clotrimazole
- Terbinafine
- Dermatophytosis. Trichophytosis (superficial and chronic, infiltrative-suppurative forms): pathogens, source, transmission routes, clinical picturo, diagnostics, differential diagnostics,
principles of treatment, prevention.
Dermatophytosis, when caused by Trichophyton species, is referred to as trichophytosis. It’s another type of fungal infection of the skin, hair, or nails and can present in various forms, including superficial, chronic, and infiltrative-suppurative. Let’s break down this infection:
### Pathogens:
- Trichophyton tonsurans
- Trichophyton rubrum
- Trichophyton verrucosum
- Trichophyton mentagrophytes
### Source:
- Direct skin-to-skin contact with infected individuals
- Contact with animals, especially with T. verrucosum
- Contaminated items such as clothing, towels, and hairbrushes
- Soil, in fewer cases
### Transmission Routes:
- Human to human
- Animal to human
- Fomites (contaminated items)
- Sometimes from soil to human
### Clinical Picture:
- Superficial Form: Scaling, itching, and ring-like lesions on the skin; may also see brittle hair over the infected area.
- Chronic Form: Less inflammatory reaction, might present as more widespread, scaly patches, common in adults.
- Infiltrative-Suppurative Forms (Kerion): Painful, purulent, swollen lesions, usually on the scalp; can lead to scarring and hair loss if not treated.
### Diagnostics:
- Wood’s Lamp Examination: Some species show fluorescence.
- Microscopy with KOH Solution: Observing fungal elements in skin or hair samples.
- Fungal Culture: Definitive identification of the fungus.
- Histopathology: Skin biopsy stained with PAS (Periodic Acid-Schiff) can be used sometimes.
### Differential Diagnostics:
- Seborrheic dermatitis
- Psoriasis
- Scalp folliculitis
- Impetigo
### Principles of Treatment:
#### Superficial Form
- Topical Antifungals:
- Terbinafine
- Clotrimazole
- Ketoconazole
- Miconazole
- Hygiene: Regular washing, not sharing personal items.
#### Chronic Form
- Oral Antifungals: Required for hair or nail involvement:
- Griseofulvin
- Terbinafine
- Itraconazole
- Fluconazole
35, Dermatophytosis. Favus (superficial and chronic, infiltrative-suppurative forms): pathogens, source, trasmission routes, clinical picture, diagnostics, di ferential diagnostics, principles of
treatment, prevention.
Dermatophytosis known as Favus is a chronic form of tinea capitis mainly caused by the fungus Trichophyton schoenleinii. Favus is recognized for its distinctive scutula lesions, which are crust-like structures on the scalp, and can lead to scarring and permanent hair loss if not treated adequately. Let’s explore Favus in detail:
### Pathogens:
The primary pathogen responsible for Favus is Trichophyton schoenleinii.
### Source:
The source is primarily human-to-human transmission, although the fungus can also live in soil and be transferred to humans indirectly.
### Transmission Routes:
- Direct contact with infected individuals
- Contact with contaminated objects, such as combs, hats, or bedding
- Rarely, from soil
### Clinical Picture:
Favus is characterized by:
- Yellow, cup-shaped crusts (scutula) on the scalp
- Hair loss at the lesion sites
- A distinctive mousy odor
- Without treatment, can lead to scarring and permanent alopecia
### Diagnostics:
- Clinical Examination: The presence of scutula is highly indicative of Favus.
- Microscopy with KOH Solution: Observation of fungal hyphae and spores from the crusts.
- Fungal Culture: To confirm the specific species of fungus.
- Wood’s Lamp Examination: May show a pale green fluorescence.
### Differential Diagnostics:
- Scalp psoriasis
- Seborrheic dermatitis
- Bacterial infections, such as impetigo
- Other forms of dermatophytosis (tinea capitis)
### Principles of Treatment:
For Favus, the following treatments are commonly employed:
#### Superficial and Chronic Forms
- Oral Antifungals: Given the chronic nature and potential for scarring and alopecia, oral antifungals are essential:
- Griseofulvin (traditional choice)
- Terbinafine
- Itraconazole
- Fluconazole
- Topical Antifungals: For adjunct treatment
### Prevention:
- Early diagnosis and treatment are crucial to prevent the spread and complications of Favus.
- Avoid sharing personal items like combs, hats, or hairbrushes.
- Good personal hygiene and regular washing of hair and scalp.
36, Candidiasis: classification, etiology, pathogenesis, classification, clinical picture, diagnosties, differential diagnosties, principles of treatment, prevention.
Candidiasis is an infection caused by fungi of the genus Candida, with Candida albicans being the most common culprit. Candidiasis can affect various parts of the body, leading to a range of clinical manifestations. Below you can find a detailed breakdown:
### Classification:
- Oral Candidiasis (Thrush)
- Vulvovaginal Candidiasis (VVC)
- Invasive Candidiasis (including candidemia)
- Cutaneous Candidiasis
- Chronic Mucocutaneous Candidiasis
### Etiology:
Most candidiasis infections are caused by Candida albicans, but other species such as Candida glabrata, Candida parapsilosis, and Candida tropicalis may also be involved.
### Pathogenesis:
- Disruption of normal flora (e.g., antibiotic use)
- Moist and warm environment
- Weakened immune system
- Hormonal changes (e.g., pregnancy)
- Diabetes mellitus
- Use of corticosteroids or immunosuppressive therapy
### Clinical Picture:
Oral Candidiasis:
White creamy patches on the tongue or oral mucosa, which can be wiped off to reveal a red base.
Vulvovaginal Candidiasis:
Vaginal itching, redness, swelling, and a thick, white discharge resembling cottage cheese.
Invasive Candidiasis:
Fever, chills, and a variety of symptoms depending on infected organs, often occurring in hospital settings.
Cutaneous Candidiasis:
Red rashes with well-defined borders, often found in folds such as under the breasts, groins, or between fingers.
Chronic Mucocutaneous Candidiasis:
Persistent candidal infections on the skin, nails, and mucous membranes.
### Diagnostics:
- Clinical examination
- Microscopy: KOH smear shows yeast and pseudohyphae.
- Culture: Identification of Candida species.
- Biopsy: In case of chronic or invasive infections.
- Blood tests: For invasive candidiasis (e.g., blood cultures).
### Differential Diagnostics:
- Bacterial infections (e.g., Streptococcal pharyngitis)
- Other fungal infections (e.g., dermatophytosis)
- Herpes simplex virus
- Lichen planus
### Principles of Treatment:
Topical Antifungals (for localized infections):
- Clotrimazole
- Nystatin
- Miconazole
Oral Antifungals (for severe or esophageal candidiasis, and VVC):
- Fluconazole
- Itraconazole
- Mucosal candidiasis: eriology, pathogenesis, classification, elinical picture, diagnosties.
diffrantial diagnosties, principles of treatment, prevention
Mucosal Candidiasis:
### Etiology:
Mainly caused by Candida albicans, but other Candida species like C. glabrata or C. tropicalis can also be involved.
### Pathogenesis:
Occurs when the balance of normal mucosal flora is disrupted or the immune system is compromised, leading to overgrowth of Candida. Common contributing factors:
- Antibiotic use
- Immunodeficiency (e.g., HIV)
- Diabetes
- Corticosteroid therapy
- Pregnancy
### Classification:
- Oral Candidiasis: Including thrush and angular cheilitis
- Oesophageal Candidiasis
- Vulvovaginal Candidiasis
- Candidal Balanitis
- Candidal Diaper Rash
- Chronic Mucocutaneous Candidiasis
### Clinical Picture:
Varies depending on site:
- Oral: White patches, redness, soreness
- Esophageal: Dysphagia, pain on swallowing
- Vulvovaginal: Itching, discharge, inflammation
- Balanitis: Erythema, itching, scaling on the penis
- Diaper Rash: Bright red rash with satellite lesions
### Diagnostics:
- Clinical examination
- KOH smear or fungal culture
- Biopsy (for refractory cases)
- Endoscopy (for esophageal candidiasis)
### Differential Diagnostics:
- Bacterial infections
- Lichen planus
- Gastroesophageal reflux disease (GERD)
- Herpes simplex virus (HSV) infections
### Principles of Treatment:
Localized candidiasis:
- Topical antifungals (nystatin or azole creams)
Moderate to severe or oropharyngeal/esophageal candidiasis:
- Systemic therapy with fluconazole or other azoles
- Amphotericin B for refractory cases
### Prevention:
- Good oral hygiene
- Control of diabetes
- Appropriate antibiotic use
- Candidiasis of large folds: etielogy, pathogenesis, classification, clinical picture, diagnostics,
difTerential diagnosties, principles of tratment, preventon.
Candidiasis of Large Folds (Intertrigo):
### Etiology:
Infection with Candida species, most commonly Candida albicans.
### Pathogenesis:
Overgrowth of Candida in warm, moist, and friction-prone areas of large skin folds due to disturbed local microenvironment, impaired immunity, or increased skin pH.
### Classification:
- Inframammary Candidiasis
- Intertriginous Candidiasis (involving other skin fold areas)
### Clinical Picture:
Bright red rashes with a distinct edge, possible oozing, satellite pustules, and discomfort or itching.
### Diagnostics:
- Clinical examination
- KOH smear showing pseudohyphae and/or yeast cells
- Culture may be used to identify species
### Differential Diagnostics:
- Psoriasis
- Erythrasma due to Corynebacterium
- Tinea infections
- Seborrheic dermatitis
### Principles of Treatment:
- Keeping the affected area dry and clean
- Topical antifungals like clotrimazole, miconazole, or nystatin
- Severe cases may require oral antifungals (fluconazole)
### Prevention:
- Regular changing of clothes to keep skin dry
- Using absorbent powders in susceptible individuals
- Weight loss to reduce skin folds
- Onychomycosis, Pathogens, elinical pieture, diagnosties, differential diagnosties, basic principles of treatment.
Onychomycosis:
### Pathogens:
Mostly caused by dermatophytes (e.g., Trichophyton rubrum), nondermatophytic molds, and yeasts (Candida species).
### Clinical Picture:
Thickening of the nail, discoloration, subungual debris, and possible separation of the nail from the nail bed (onycholysis).
### Diagnostics:
- Visual inspection
- KOH preparation to view fungi
- Nail clippings for culture and histological examination using PAS (Periodic Acid-Schiff) staining
### Differential Diagnostics:
- Psoriasis
- Lichen planus
- Traumatic nail dystrophy
- Nail bed tumors
### Basic principles of Treatment:
- Oral antifungal agents: terbinafine, itraconazole, fluconazole
- Topical treatments: ciclopirox, efinaconazole, amorolfine nail lacquers
- Mechanical debridement of the affected nail(s)
- Photodynamic therapy and laser treatments in some resistant cases
### Prevention:
- Good foot hygiene
- Keeping nails short and dry
- Wearing breathable shoes and socks
- Dermatitis: simple contact, allergie, General characteristies, differential diagnostics,
principles of trealment.
Dermatitis:
### Simple Contact Dermatitis:
General Characteristics: Caused by direct skin contact with irritants like soaps, chemicals, or detergents leading to non-allergic irritation of the skin.
### Allergic Contact Dermatitis:
General Characteristics: An immune-mediated response where the skin develops a rash after exposure to an allergen, which is a substance the person’s immune system recognizes as foreign.
### Differential Diagnostics:
- Psoriasis
- Atopic dermatitis
- Seborrheic dermatitis
- Urticaria
- Infections
- Photodermatitis
### Principles of Treatment:
- Identification and avoidance of the irritant or allergen
- Topical steroids like hydrocortisone for inflammation and itching
42, Toxidermia (fixed erythema, Lyell’s discase, Stevens-Johnson syndrome, ete.): definition, etiopathogenesis, clinical picture, principles of treatment, prevention.
Toxidermia:
### Definition:
Toxidermia refers to skin manifestations resulting from a systemic reaction to drugs or toxins.
### Etiopathogenesis:
Drug-induced toxidermia is caused by adverse reactions to medications, which may be dose-dependent or idiosyncratic.
### Clinical Picture:
- Fixed Drug Eruption: Singular or multiple round, red or purple patches that recur at the same site upon re-exposure to a drug.
- Toxic Epidermal Necrolysis (Lyell’s Disease): Severe, life-threatening condition with widespread skin peeling and mucosal involvement.
- Stevens-Johnson Syndrome (SJS): A milder form of TEN with less than 10% body surface area involvement but with similar systemic symptoms.
### Principles of Treatment:
- Immediate discontinuation of the suspected drug
- Supportive care and monitoring in a hospital setting, potentially including intensive care for severe cases
- Fluid and electrolyte balance maintenance
- Wound care for skin lesions
- Analgesics for pain management
- Corticosteroids may be used in early stages of SJS but are controversial in TEN
- Immunosuppressants like cyclosporine or IVIG (intravenous immunoglobulin) may be considered in certain case
### Prevention:
- Avoiding known drug allergies
- Use of alert bracelets or carrying cards with drug allergy information
- Slow trial doses for medications when a history of drug reactions exists
- Unicaria: classification, etiopathogenests, clinical picture, treatment principles, relapse
prevention. Quincke’s clemas ctiopathogenesis, clinical picture, lintaid
Urticaria (Hives):
### Classification:
1. Acute Urticaria: Lasts less than six weeks. Causes can include certain foods, medications, infections, insect stings, or stress.
2. Chronic Urticaria: Persists for longer than six weeks and often has no identifiable cause.
### Etiopathogenesis:
Triggered by histamine release from skin mast cells and basophils, often due to allergies, but can also be caused by factors such as infection, stress, or temperature extremes.
### Clinical Picture:
Presents as red, raised, itchy welts that vary in size and can migrate and coalesce on any part of the skin.
### Treatment Principles:
1. Antihistamines: Such as cetirizine, loratadine, fexofenadine.
2. Corticosteroids: Short courses of oral steroids for severe acute urticaria.
3. Leukotriene Receptor Antagonists: Montelukast may be useful in combination with antihistamines.
4. Omalizumab: For chronic spontaneous urticaria unresponsive to antihistamines.
### Relapse Prevention:
Patient education to identify and avoid triggers, long-term management with the lowest effective dose of medication, and regular follow-up.
### Quincke’s Edema (Angioedema) Etiopathogenesis and Clinical Picture:
- Etiopathogenesis: Often occurs in conjunction with urticaria; hereditary angioedema is due to C1 inhibitor deficiency. Can be triggered by medications (ACE inhibitors), allergens, and unknown causes.
- Clinical Picture: Sudden onset of swelling in the deeper layers of the skin, typically around the eyes and lips, and sometimes the genitals, hands, and feet.
### Treatment:
1. Antihistamines: If associated with urticaria.
2. Corticosteroids and Antihistamines: For acute attacks.
3. C1 Inhibitor Concentrate: For hereditary angioedema episodes.
4. Fresh Frozen Plasma: Can be used in acute hereditary angioedema.
- Skin itching: etiopathogenesis, diagnosties, differential diagnosties, treatment
Skin Itching (Pruritus):
### Etiopathogenesis:
1. Dry Skin: Common, especially in older age.
2. Dermatological Conditions: Eczema, psoriasis, hives.
3. Systemic Diseases: Liver disease, kidney failure, thyroid disorders.
4. Allergic Reactions: To drugs, food, or other allergens.
5. Parasitic Infections: Such as scabies.
### Diagnostics:
1. Thorough medical history and physical examination.
2. Blood tests to check liver, kidney, and thyroid function, and possibly blood cell counts.
3. Skin tests for allergies.
4. Biopsy of skin lesions if present.
### Differential Diagnostics:
1. Differentiating from conditions that primarily cause skin lesions like psoriasis or eczema.
2. Systemic causes such as liver or kidney disease.
3. Neurologic conditions that cause itching without rash.
### Treatment:
1. Moisturizers: For dry skin.
2. Topical Corticosteroids: For dermatologic causes like eczema.
3. Antihistamines: Such as cetirizine or diphenhydramine, for allergic reactions.
4. Phototherapy: For systemic and severe dermatological causes.
- Alepic dermatitis: definition, etiopathogenesis, clinical characteristies of the stages of the process, diagnusties, differential diagnosties, principles of therapy and prevention.
Atopic Dermatitis (Eczema):
### Definition:
A chronic, inflammatory skin condition characterized by red, itchy, and sometimes oozing rashes.
### Etiopathogenesis:
1. Genetic predisposition.
2. Impaired skin barrier function.
3. Immune system dysregulation.
4. Environmental factors, such as allergens or irritants.
5. Stress can exacerbate the condition.
### Clinical Characteristics of the Stages:
1. Acute: Erythema (redness), vesicles (small blisters), weeping, and pruritus (itching).
2. Subacute: Scaling, erythema, and less weeping.
3. Chronic: Lichenification (thickened skin), scaling, and fibrotic papules.
### Diagnostics:
1. Medical history evaluation.
2. Physical examination and assessment of skin.
3. Blood tests for allergens, including IgE levels.
4. Skin patch testing for environmental allergens.
### Differential Diagnostics:
1. Psoriasis.
2. Seborrheic dermatitis.
3. Contact dermatitis.
4. Skin infections such as scabies or fungal infections.
### Principles of Therapy:
1. Skin Care: Regular use of emollients and moisturizers to improve skin barrier function.
2. Topical Corticosteroids: For flare management and to reduce inflammation.
3. Topical Calcineurin Inhibitors: Tacrolimus and pimecrolimus for inflammation without the side effects of steroids.
4. Systemic Therapies: For severe cases, systemic corticosteroids or newer agents like dupilumab may be used.
- Eczema: clioputhogenesis, classification, clinical features, diagnustics, differential diugnostics, principles of general and local ucatment.
Eczema (Dermatitis):
### Cliopathogenesis:
A combination of genetic, environmental, and immunological factors causing inflammation and barrier dysfunction of the skin.
### Classification:
1. Atopic Dermatitis: Typically begins in childhood, often associated with asthma and allergic rhinitis.
2. Contact Dermatitis: A result of skin contact with allergens or irritants.
3. Dyshidrotic Eczema: Small fluid-filled blisters on hands and feet.
4. Nummular Eczema: Round patches of irritated skin that can be crusted, scaling, and itchy.
5. Seborrheic Dermatitis: Oily, scaly yellowish patches of skin, often on the scalp and face.
### Clinical Features:
- Itchiness.
- Red to brownish-gray patches.
- Small, raised bumps, which may leak fluid when scratched.
- Thickened, cracked, or scaly skin.
- Sensitive and swollen skin from scratching.
### Diagnostics:
1. Medical history and physical exam.
2. Skin biopsy (rarely needed).
3. Patch testing for contact dermatitis.
### Differential Diagnostics:
1. Psoriasis.
2. Scabies.
3. Fungal infections.
4. Lichen planus.
### Principles of General Treatment:
1. Anti-Inflammatory Medications: Systemic corticosteroids for severe flares.
2. Immunosuppressants: Cyclosporine, methotrexate, or mycophenolate mofetil in chronic cases
### Principles of Local Treatment:
1. Topical Corticosteroids: Varying potencies based on severity and location of eczema.
2. Topical Calcineurin Inhibitors: Such as tacrolimus or pimecrolimus.
3. Moisturizers: To hydrate and repair skin barrier.
4. Topical Antibiotics: If secondary infection is present.
- Scabies: etiopathogenesis, classification, clinical picture, diagnostics, differential diagnostics, principles of treatment, prevention.
Scabies:
### Etiopathogenesis:
Caused by the mite Sarcoptes scabiei, an obligate parasite that burrows into the skin to lay eggs, causing intense itching.
### Classification:
1. Typical Scabies: Common infestations characterized by burrows and papular rash.
2. Norwegian (Crusted) Scabies: Severe form with thick crusts, seen in immunocompromised individuals.
3. Nodular Scabies: Persistent nodules occur, particularly in the groin or axillary regions.
### Clinical Picture:
- Intense itching, especially at night.
- Pimple-like irritations or a rash.
- Scales or blisters.
- Sores caused by scratching.
- Linear burrows into the skin.
### Diagnostics:
1. Clinical evaluation of skin lesions.
2. Microscopic examination of skin scrapings for mites, eggs, or fecal matter.
3. Dermoscopy can aid in identifying burrows.
### Differential Diagnostics:
1. Eczema.
2. Psoriasis.
3. Folliculitis.
4. Atopic dermatitis.
### Principles of Treatment:
1. Topical Permethrin: First-line treatment to be applied to the whole body.
2. Ivermectin: Oral medication for severe cases or for those who didn’t respond to topical treatment.
3. Lindane: An alternative treatment, although neurotoxicity restricts its use.
