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
What are the features of erythema multiforme?
target lesions, initially seen on back of hands or feet which spread towards torso. more common in upper limbs.
pruritis can be seen.
What are the causes of erythema multiforme?
What happens in erythema multiforme major?
HSV
idiopathic
mycoplasma, streptococcus
penicillin, carbamazepine, sulfonamides, allopurinol, NSAIDs, COCP
mucosal involvement
What are the features of erythema nodosum?
What are the causes?
inflammation of subcutaneous fat, nodular erythematous, tender lesions on shins
resolves within 6 weeks
streptococci, TB
IBD, sarcoidosis
malignancy, lymphoma
What is erythroderma and what are the causes?
When any rash covers more than 95% of the body
gold
eczema
psoriasis
lymphomas, leukaemias
name three causes of hirsutism
PCOS
cushing’s
congenital adrenal hyperplasia
what is the management of localised impetigo?
what is the management of extensive impetigo?
what is the school exclusion criteria for impetigo?
topical fusidic acid
oral flucloxacillin
oral erythromycin if penicillin allergic
school exclusion until lesions are crusted over or 48h until antibiotic treatment is started
what are the features of a keratoacanthoma?
initially a smooth, dome shaped papule
grows to become a crater centrally filled with keratin
looks like a volcano
what is the Koebner phenomenon?
when skin lesions form at sites of trauma
seen in;
psoriasis vitiligo warts lichen planus lichen sclerosis molluscum contagiosum
What is leukoplakia?
pre-malignant white hard plaques found in the mouth
DDx: candidiasis and lichen planus (however these can be rubbed off)
What are the features of lichen planus?
What is the management?
itchy, papular rash (white lace pattern) often polygonal in shape
oral involvement in 50% of patients
topical steroids
benzydamine mouth wash (if oral)
extensive? = oral steroids
What are the features of lichen sclerosis?
most commonly in elderly females in the genitalia
atrophy of epidermis with white plaques forming
management is topical steroids and emollients
follow up: increased risk of vulval cancer
What are the features of molluscum contagiosum?
If you wanted to treat it, what is the management?
pink or pearly white papules with central umbilication
appear in clusters on the body
contagious (do not share towels, baths etc)
usually self limiting (18m). do not scratch.
squeezing with fingernails or piercing after a bath
cryotherapy
if extensive itching = emollient and topical corticosteroid
if infected skin = prescribe a topical antibiotic (fusidic acid)
what is mycosis fungoides?
rare form of T cell lymphoma that affects skin
itchy, red patches which are confused with eczema and psoriasis initially
what is pellagra and what is it caused by? what are the three D’s?
caused by nicotinic acid (niacin) deficiency
classical features: dementia, diarrhoea, dermatitis
what are the features of pemphigus vulgaris?
what is the management?
autoimmune disease against desmoglein-3
most common in the Ashkenazi Jewish population
mucosal ulceration: common and happens first.
skin blistering: flaccid, easily ruptured, painful but not itchy
management: steroids and immunosuppression
