Random 1 Flashcards
What are the features of acanthosis nigricans?
What may cause acanthosis nigricans?
Symmetrical, brown, velvety plaques found in neck, axilla and groin
GI cancer diabetes obesity PCOS acromegaly cushing's disease
What is actinic keratosis and how does it present?
Premalignant, small crusted lesions in sun exposed areas. May be any colour.
What is the management of actinic keratosis?
sun avoidance, sun cream topical fluorouracil (2-3w), skin will become red and inflamed, give topical hydrocortisone topical diclofenac topical imiquimod cryotherapy
Outline skin prick testing
Drops of diluted allergen are placed on the skin after which a needle pierces the skin.
A wheal will develop if there is an allergy.
Takes 15 minutes.
What is a radioallergosorbent test (RAST)?
determines the amount of IgE that reacts with specific allergens
the reactions are graded from 1 to 6
Outline skin patch testing
useful for contact dermatitis
30-40 allergens are placed on the back
the patches are removed 48 hours later
What treatments are there for alopecia areata?
topical corticosteroids
topical minoxidil
phototherapy
dithranol
What is athlete’s foot and what is the treatment of it?
tinea pedis. scaling, flaking and itching between toes
topica imidazole, or terbinafine
What are the features of bullous pemphigoid?
What investigation is used for bullous pemphigoid?
autoimmune, more common in elderly
subepidermal blistering of the skin
itchy, tense blisters around flexures
heal without scarring
immunofluorescence shows IgG and C3 deposits
What is the management of bullous pemphigoid?
referral to dermatologist for skin biopsy and confirmation
oral corticosteroids
topical corticosteroids and immunosuppressants.
What are cherry hemangiomas?
also called senile hemangiomas or Campbell de Morgan spots
occur in old age erythematous, papular lesions 1-3mm in size non-blanching benign, no relationship to cancer
What is chondrodermatitis nodularis helicis?
What is the management of it?
benign, painful nodule on ear
associated with pressure (sleep, headsets)
reduce pressure on ear (foam protectors)
cryotherapy, steroid injection, collagen injection
Outline contact dermatitis and the two subtypes
irritant contact dermatitis: non allergic reaction due to weak acids and alkalis (e.g. detergents)
allergic contact dermatitis: type IV hypersensitivity reaction. acute weeping eczema, affects the margins of hairlines. topical potent steroid treatment.
What are the features of dermatitis herpetiformis?
What are the associations?
How do you diagnose dermatitis herpetiformis?
What is the management?
itchy, vesicular skin lesions on extensor surfaces
coeliac disease
skin biopsy: immunofluorescence shows IgA deposits
gluten free diet and dapsone
What is erythema ab igne?
spider web appearance, similar to livedo reticularis (reticulated, erythematous pattern)
overexposure to infrared radiation
may go on to develop squamous cell cancer