Integumentary pathologies Flashcards
Acne Roseacea
Chronic inflammation of the skin associated with vascular changes, which results in flushing
Pathophysiology:
* Often accompanied by seborrhoea (excessive discharge of sebum) but is not an inflammation of the follicles
Causes:
* More common - women
* Exaggerated vasodilatory response to hyperthermia
* High incidence of gastric Helicobacter Pylori found in rosacea patients (88%)
* Flushing reaction may be caused by gastrin (gastrin = H. pylori growth)
* Environmental (oil, chlorine, UV), cosmetics (e.g. paraffin), medications, stress
Signs and symptoms:
* Facial flushing – redness across nose and cheeks, seborrhoae (oily skin) with papules, pustules
Other:
* Suspected that other organs are affected too, such as the stomach and intestines
Acne Vulgaris
Blockage of sebaceous / hair follicle duct
Pathophysiology:
* In acne, oil that normally drains to the skin surface, gets blocked by excess skin cells inside the follicle. This provides an ideal location for bacteria to grow
* Foods that are high in glucose and elevate insulin levels promote oil production and excess skin cell production in follicles. They also cause the testes (and ovaries) to produce testosterone. Dairy will do the same
Causes:
* More common in males
* Onset is typically at puberty
* Links to excess testosterone
* Premenstrual hormonal imbalances
* Oily creams and some drugs (anabolic)
* High prevalence in Western populations (signifies environmental factors inc, diet)
Signs and symptoms:
* Closed comedones (whiteheads): when the trapped sebum and bacteria stay below the skin surface
* Open comedones (blackheads): Oxidised lipids causes dark colour
* ‘Inflammatory acne’ can occur which begins as closed comedones. Distension of the follicle occurs causing inflammation (red papules)
* Cysts can occur when folliucles rupture rsulting in a pustule / nodule
* Large, deep pustules can break down adjacent tissue and cause scarring
Atopic Dermatitis / Eczema
An immune-mediated inflammation of the skin due to the interaction between genetic and environmental factors
Causes:
* Genetic weaknesses in epidermal barrier function
* Some patients have mutation in the filaggrin gene, a structural protein in the statum corneum
* Loss of filaggrin may result in impaired skin’s barrier function, leading to entry of foreign environmental substances that may trigger immune responses
* The skin may be deficient in ‘ceramides’ (fatty acids) increasing transepidermal water loss
* IgE involved in 70-80% of cases, ‘true allergy’
* Predominance of pathogenic Staphylococcus aureus in the skin flora of 90% of patients
Common allergens:
* Foods (milk, eggs, soy, wheat, peanuts, fish)
* Airborne (dust mites, mould, pollen)
Signs and symptoms:
* Pruritis is the primary symptom
* Red scaly lesions on flexor surfaces and cheeks. Very itchy
* Broken skin on scratching = lichenification
* Infection on skin (very inflamed with pus)
Allopathic treatment:
* Corticosteroids
* Soap substitutes
Complications:
* Secondary bacterial infections
Other:
* Usually occurs in infancy / childhood
* Primarily affects children in urban areas or developed countries, and prevalence has increased over the last 30 years
* Family history of atopic disorders in 2 out of 3 cases: Asthma or allergic rhinitis
Burns
Injury to the skin or tissues caused by heat, cold (frostbite), electricity, radiation, chemicals (strong acids / bases)
Signs and symptoms:
* Damage of the skin with necrosis = pain
* Electrical burns injuries may extend beyond tissue damage (cardiac arrhythmia / fibrillation, etc.)
Allopathic treatment:
* Skin grafting for deep burns,
* Fluid and electrolyte replacement
* Pain management
Complications:
* Dehydration – due to loss of water and plasma through damaged skin surface
* Hypothermia – due to impaired thermoregulation and heat loss
* Hypovolaemic shock
* Infection
* Renal failure – if the kidneys cannot filter waste from broken-down red blood cells and damaged tissue
* Contractures – scar tissue contracts distorting skin and impairing movement
Other:
Classification:
1st degree: affects the epidermis
2nd degree: All of epidermis and some dermis
3rd degree: Extends into subcutaneous tissue
4th degree: Extends into muscles and tendon
Comedone (Acne)
Blackheads, whiteheads or red bumps due to excess sebum, keratin and debris forming a plug in the sebaceous duct of a hair follicle
Signs and symptoms:
* Hormones i.e. testosterone can cause more and thicker oil secretions that block pores
* Open comedo; Blackhead (acne vulgaris) – if oil is open to the air, it will oxidise = turns dark
* Closed comedo: Whitehead. If skin has grown over oily material, it remains white
Contact Dermatitis
An acute inflammation of the skin caused by direct contact with an agent. Divided into irritant (80%) and allergen (20%)
Causes:
Irritant contact dermatitis (ICD):
* Non-specific inflammatory reaction to a substance contacting skin
* Abrasive chemicals can corrode the epidermis causing cutaneous ulceration
* Hands are vulnerable due to frequent occupational exposure to soap (that can abrade the lipids in skin)
* A type called phototoxic dermatitis in which topical (e.g. perfumes) or ingested irritants are activated by exposure to UV rays
Allergen contact dermatitis (ACD):
* A type of delayed hypersensitivity reaction
* Sensitisation occurs on first exposure
* Pruritic, erythematous rash develops at the site on subsequent exposures
* Can occur with various chemicals, rubber, plants, metals
* Multiple allergens cause ACD and cross-sensitisation among agents is common
* A variant called photoallergic contact dermatitis in which a substance becomes allergenic only after it undergoes a structural change triggered by UV light; e.g. sunscreens
Signs and symptoms:
* Location of symptoms can give a clue to the irritant / allergen
* Pruritic rash, often burning, stinging, eroded, blistered skin
* Irritant contact dermatitis = ulceration, burning, prickling, soreness and quicker onset of symptoms
* Allergen contact dermatitis = pruritis is significant, but slower onset of symptoms
Allopathic treatment:
* Remove allergen.
* Steroids and Antihistamines
Complications:
* Secondary bacterial infections
Crust (skin lesions)
Abnormal / damaged tissue with impaired function of skin
Signs and symptoms:
* Collection of dried body fluid (blood plasma and exudate) and dead skin cells (a scab)
N/B; Exudate; any fluid that filters from the blood
Erosion
Shallow, moist cavity in the epidermis
Signs and symptoms:
* Wearing away with loss of superficial epidermis (from chemicals, friction or pressure)
* Ulcer in diabetes
Keloid
Raised, irregular mass of collagen due to scar tissue formation
Signs and symptoms:
* Abnormal scar tissue that grows beyond the skin boundary
* Strong genetic links. Vaccination site, scratching, burns
Lichenification
Thick, dry, rough plaques of thickened skin
- Visible thickening of epidermis, with accentuated skin markings / pronounced lines
- Bark-like appearance
- The hallmark chronic eczema / dermatitis or excessive scratching
Macule
Small, flat, circumscribed lesion of a different colour to normal skin
Signs and symptoms:
* A change in surface colour, without elevation or depression (non-palpable
Nodule
Palpable elevated lesion
Signs and symptoms:
* Morphologically similar to the papule, but is bigger and deeper; e.g. rheumatoid arthritis
* May be filled with inflamed tissue or fluid
Papule
A small, firm, elevated lesion
Signs and symptoms:
* Circumscribed, solid elevation of skin with no visible fluid
* Can be either brown, purple, pink or red in colour
* Can see ‘maculopapular rash’ like in measles
Pustule
Small, elevated, erythematous lesion containing pus
Signs and symptoms:
* Purulent material usually consists of necrotic inflammatory cells
* These can be white or red
Skin Lesions
Abnormal / damaged tissue with impaired function of skin
