Skin Conditions Flashcards
Seborrhoeic dermatitis
long-term skin disorder. Symptoms include flaky, scaly, greasy, and occasionally itchy and inflamed skin. Areas of the skin rich in oil-producing glands are often affected including the scalp, face, and chest
Erythroderma
a serious dermatological emergency, characterised by widespread erythema affecting over 90% of the skin surface due to inflammatory skin disease. It often precedes or is associated with exfoliation (skin peeling off in scales or layers), when it may also be known as exfoliative dermatitis (ED).
Its primary signs and symptoms include significant skin redness and potential systemic symptoms due to heat and fluid loss.
A broad range of conditions, such as dermatitis and psoriasis, or external triggers like drug allergies, can provoke erythroderma
Contact dermatitis
type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling
Occupations at greatest risk for developing irritant contact dermatitis include: chefs, hairdressers, metal workers, nurses, cleaners and construction workers.
Atopic dermatitis
Atopic dermatitis (eczema) is a condition that causes dry, itchy and inflamed skin. It’s common in young children but can occur at any age. Atopic dermatitis is long lasting (chronic) and tends to flare sometimes. It can be irritating but it’s not contagious.
Characterized by dermal inflammation leading to histological changes in the epidermis such as spongiotic change, acanthosis, hyperkeratosis, and parakeratosis.
Typical signs and symptoms include itchiness, erythema, and oozing, which may evolve into dry, flaky skin and lichenification.
People with atopic dermatitis are at risk of developing food allergies, hay fever and asthma.
Atopic dermatitis often begins before age 5 and may continue into the teen and adult years. For some people, it flares and then clears up for a time, even for several years.
Psoriasis
Psoriasis is a chronic autoimmune disease characterised by well-demarcated, pruritic, erythematous, scaly plaques
This is due to uncontrolled keratinocyte proliferation and dysfunctional differentiation, leading to epidermal acanthosis, hyperkeratosis, and parakeratosis.
usually on the extensor surfaces
Pityriasis rubra pilaris
a group of chronic disorders characterized by reddish orange, scaling plaques and keratotic follicular papules. Symptoms may include reddish-orange patches on the skin, severe flaking, uncomfortable itching, thickening of the skin on the feet and hands, and thickened bumps around hair follicles. For some, early symptoms may also include generalized swelling of the legs, feet and other parts of the body.
Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome
a severe hypersensitivity reaction to certain medications
characterised by an extensive skin rash, fever, hematologic abnormalities, lymphadenopahy and multi-organ involvement
Toxic epidermal necrolysis (TEN) and Stevens-Johnson Syndrome (SJS)
SJS/TEN is a rare, acute, serious, and potentially fatal immune-complex-mediated hypersensitivity skin reaction in which there are sheet-like skin and mucosal loss - extensive skin detachment, mucosal involvement, and systemic symptoms.
Distinct from erythema multiforme.
SJS affects <10% of skin surface = 10% mortality
TEN affects >30% - is worse = 30% mortality
** Positive Nikolsky** sign
Causes: Adverse drug reactions most commonly:
- Beta-lactam (penicillins and cephalosporins)
- Anti-epileptics (e.g. Lamotrigine)
- Allopurinol
- NSAIDs
- Combined oral contraceptive pill
Other:
- HSV
- EBV
- HIV
- Influenza
- Hepatitis
Staphylococcal scalded skin syndrome (SSSS)
a rare, severe, superficial blistering skin disorder which is characterised by the detachment of the outermost skin layer (epidermis). This is triggered by exotoxin release from specific strains of Staphylococcus aureus bacteria.
The blistering of large areas of skin gives the appearance of a burn or scalding, hence the name staphylococcal scalded skin syndrome
Acne rosacea
a common skin condition characterized by facial flushing, predominately affecting women aged 30-60 with pale skin. Key signs and symptoms include facial redness, telangiectasia, and various subtypes such as papulo-pustular rosacea, rhinophymatous rosacea, and ocular rosacea
Acne Vulgaris
a common chronic disorder of the pilo-sebaceous unit, resulting in blockage of the follicle, formation of comedones and inflammation.
Key signs and symptoms include open/closed comedones, inflammatory papules and pustules, and in severe cases, nodules and cysts. The disorder predominantly affects the face, neck, chest, and back
Actinic keratosis (AK)
A premalignant skin condition that can lead to squamous cell carcinoma (SCC). The key signs and symptoms include the formation of thickened papules or plaques with surrounding erythematous skin and a keratotic, rough, warty surface
Alopecia
A medical term for hair loss from areas where hair typically grows. It may present in scarring or non-scarring forms, and its aetiology ranges from autoimmune disease to infections or trauma. Key signs and symptoms depend on the cause, but generally include hair thinning or loss in patches or diffusely
Basal cell carcinoma (BCC)
a type of skin cancer originating from the basal keratinocytes within the epidermis, commonly resulting from UV-induced DNA damage.
BCC is typically asymptomatic, characterised by slow-growing, flesh-coloured nodules often with a central depression and telangiectasia. an ulcerated centre may be present = rodent ulcer
It is typically slow-growing and rarely metastasizes but can lead to significant local tissue destruction if left untreated.
Celluitis
bacterial infection affecting the dermis and subcutaneous tissue, commonly caused by Streptococcus and/or Staphylococcus organisms. The infection often presents with erythema, calor, swelling, pain, poorly demarcated margins, lymphadenopathy, and potential systemic upset like fever and malaise. Common risk factors include advancing age, immunocompromised states, and predisposing skin conditions.
Chickenpox
highly contagious disease caused by the varicella virus, or human herpes virus 3 (HHV3). Characterised by a raised, red, itchy rash that begins on the face or chest and spreads throughout the body, it progresses into small fluid-filled blisters that crust over within a few days. Chickenpox primarily affects children, but adults can contract the disease.
Allergic contact dermatitis
Presents as an itchy, eczematous rash (vesicles, fissures, erythema), typically 24-48 hours after exposure. The rash may extend beyond the boundaries of immediate contact.
patient is sensitised to the allergen over time, so they may have never had a problem in the past with the material until their presentation.
Typical allergens are nickel (found in jewellery/watches/metal buttons on clothing), acrylates (in nail cosmetics), fragrance, rubber/plastics, hair dye, and henna (paraphenylenediamine)
Irritant contact dermatitis
eczema due to contact with an irritant. There may be burning, pain, and stinging. Eczematous rash appears localised to the direct area of contact
Anyone may develop this, but at higher risk of skin barrier is compromised from pre-existing skin disease (e.g. atopic eczema)
Shingles
Reactivation of the varicella zoster virus which can lie dormant in nerve ganglia following primary infection (chickenpox)
Congenital Melanocytic Naevus
Present at birth but are very rare.
Usually quite large and hairy.
Dysplastic Naevus
An atypical naevus that may resemble a melanoma, by having ‘ABCDE’ features.
They may be part of a syndrome called Familial Atypical Multiple Mole-Melanoma (FAMMM) syndrome, where there are multiple naevi (>50) many of which are atypical and an increased risk of melanoma.
Blue Naevus
a naevus which is blue in colour as melanocytes are very deep in the skin - benign
Beckers naevus
Irregular, hyperpigmented patch usually affecting the shoulders of males
becomes darker and hairy during puberty
Halo naevus
melanocytic naevus which us surrounded by a white halo - immune system recognises mole and tries to get rid of it.
Usually benign
Spitz naevus
A red, dome-shaped papule that is commonly found on the face of children - Benign
Keloid scar
Benign, abnormal over-proliferation of scar tissue following a cutaneous injury. May be a minor or sig. injury and typically forms 3-4 weeks following injury
Impetigo
A highly infectious superficial epidermal infection primarily caused by Staphylococcal or Streptococcal bacteria, commonly found in infants and school-aged children.
Characteristic clinical signs include erythematous macules that vesiculate or pustulate, followed by superficial erosion with a golden crust
Henoch-Schönlein Purpura (HSP)
IgA-mediated, small vessel vasculitis that primarily affects the skin, gastrointestinal tract, and kidneys.
Characteristic of:
- palpaple purpura over extensor surfaces of the lower limb
- abdo pain
- arthritis, typically of the largejoints
- renal involvement
in young children be careful of Intussusception
Guttate Psoriasis
Multiple small, tear-drop shaped, erythyematous plaques on the trunk after a streptococcal infection in young adults
Subungual hyperkeratosis
Thickening of the nailbed
Onycholysis
Separation of nail plate from nailbed
Hypertrichosis
Abnormal amount of hair growth over the body.
- generalized hypertrichosis, occurs over the entire body
- localized hypertrichosis, restricted to a certain area.
Scabies
Highly contagious infestation of the mite scabei
- symptoms present 30 days after initial infection as it is a delayed type IV hypersensitivity reaction
Presentation:
- intensely itchy rash that usually affects the inter-web spaces, flexures of the wrist, axillae, abdomen and groin.
- itch is classically worse at night.
- rash is usually papular or vesicular and superficial burrows may often be seen
Treatment:
- topical permethrin 5% + treat household members and other contacts (on same day)
Norwegian (or crusted) scabies
- Where an individual is affected by millions of mites causing a generalised scaly rash- it is seen in immunocompromised patients (eg those with HIV).
- Admission to hospital may be required and get a specialised
Erythema nodosum
A form of Panniculitis, or inflammation of the subcutaneous fat, manifesting as tender, raised, red nodules typically effecting the shins
Also accompanied w systemic symptoms:
- Fever, malaise, and arthalgia in some cases
Common causes NODOSUM:
- NO cause (Idiopathic)
- Drugs: particularly sulfonamides and dapsone
- Oral contraceptive pill
- Sarcoidosis
- Ulcerative colitis and Crohn’s disease
- Microorganisms: TB, Streptococcus, Toxoplasmosis
Pityriasis rosea
A self-limiting rash that resolves after 10 weeks characterised by a herald patch and subsequent fir/Christmas-tree pattern eruption - multiple small, erythematous, scaly patches (similar but smaller than the herald patch)
- Assoc. w viral infections and drugs and vaccines
- Follows L angers lines
Pyoderma gangrenosum
Deep pustular ulcer usually on leg or site of minor injury
Characteristically:
- edge of ulcer is blue/red and overhanging and the ulcer is very painful
Staphylococcal scalded skin syndrome (SSSS)
A severe desquamating (peeling) rash and superficial blisters that primarily affects infants. - and erythroderma affecting >90% of body surface
Cause: Staph aureus -> exfoliative exotoxins -> destruction of epidermis layer (exotoxin splits epidermis in granular level, targeting desmoglein 1)
Positive Nikolsky sign
Oral mucosa usually unaffected unlike in TEN
Fever and irritability are common
Dermatofibroma
A slow-growing skin lesion that typically presents as a firm, raised nodule on the skin’s surface benign nodule caused by proliferation of fibroblasts, commonly triggered by trauma.
Multiple dermatofibromas are sometimes found in immune conditions such as HIV and SLE.
Signs and symptoms(including the above):
- typically <1cm
- Variable coloration, often brown or reddish-brown
- A dimple or central depression (known as the “dimple sign”) when the lesion is squeezed or pinched
- Asymptomatic or mild tenderness upon pressure
Folliculitis
An itchy red rash of pustules in an area around hair follicles. => anywehere on the body (except the soles or palms), but is most common on the neck, armpit or groin
Most common cause: Staph aureus
Measles
Highly contagious
- Caused by: measles morbillivirus - a single stranded enveloped RNA virus
- Transmission: droplets from the nose, mouth or throat of infected persons
- Most common in unvaccinated children
Signs/symptoms: develop 10-14 days post-exposure, last 7-10 days
- fever >40
- Corzyal symptoms
- Conjunctivitis
- Maculopapular Rash 2-5 days after onset of symptoms
- Koplik spots: grey discolorations of the mucosal membranes in the mouth
Investigations for suspected measles include:
- 1st: Measles-specific IgM and IgG serology (ELISA), most sensitive 3-14 days after onset of the rash.
- 2nd: Measles RNA detection by PCR, best for swabs taken 1-3 days after rash onset.
Lichen Planus
Chronic inflammatory disorder mediated by T cells, manifesting as pruritic, polygonal, planar, purple papules or plaques, also known as the 6 P’s, often with white lacy lines (Wickham’s striae) which can not be whipped off
Presentations:
- Cutaneous, oral and genital lesions and possibly scarring alopecia (lichen planopilaris)
Causes:
- Idiopathic or triggered by factors such as Hepatitis C, allergic contact dermatitis, localised skin injury or infection, or specific medications.
Molluscum Contagiosum
- Common, contagious skin infection caused by the molluscum contagiosum virus, a member of the poxvirus family.
- Small, pearly papules with central umbilication, often occurring on the genitals
- Resolves spontaneously within 18 months, distressing cosmetic implications may warrant treatment such as cryotherapy.
