Dermatology Flashcards
causes of acanthosis nigricans
type 2 diabetes mellitus
gastrointestinal cancer
obesity
polycystic ovarian syndrome
acromegaly
Cushing’s disease
hypothyroidism
familial
Prader-Willi syndrome
drugs (combined oral contraceptive pill, nicotinic acid)
describe the appearance of acanthosis nigricans
symmetrical, brown, velvety plaques that are often found on the neck, axilla and groin
insulin resistance → hyperinsulinemia → stimulation of keratinocytes and dermal fibroblast proliferation via interaction with insulin-like growth factor receptor-1 (IGFR1)
types of acne lesions
comedones - due to a dilated sebaceous follicle
inflammatory lesions - when the follicle bursts releasing irritants
excess inflammatory response - in nodules and cysts
drug induced acne - monomorphic
acne fulminans - severe acne + fever
classification of acne
mild: open and closed comedones with or without sparse inflammatory lesions
moderate acne: widespread non-inflammatory lesions and numerous papules and pustules
severe acne: extensive inflammatory lesions, which may include nodules, pitting, and scarring
managing mild-moderate acne
12 week topical combination therapy
topical adapalene with topical benzoyl peroxide
topical tretinoin with topical clindamycin
topical benzoyl peroxide with topical clindamycin
managing moderate-severe acne
topical adapalene with topical benzoyl peroxide
topical tretinoin with topical clindamycin
topical adapalene with topical benzoyl peroxide + oral lymecycline/oral doxycycline
oral isotretinoin - only initiated under specialist supervision
additional management information in acne
avoid tetracyclines in children, pregnant/breastfeeding - use erythromycin instead
always co-prescribe topical tx with oral antibiotics to reduce chance of antibiotic resistance developing
refer if acne congloboate
consider referring if no response to 2 course of tx, acne with scarring and permanent changes, causes stress or MH disorder
features of actinic keratosis
common premalignant skin lesion
consequence of chronic sun exposure
small, crusty or scaly, lesions
may be pink, red, brown or the same colour as the skin
typically on sun-exposed areas e.g. temples of head
multiple lesions may be present
management of actinic keratoses
fluorouracil cream: 2-3w - skin becomes red and inflamed (+ topical hydrocortisone to settle inflammation)
topical diclofenac - for mild disease
cryotherapy
features of alopecia areata
autoimmune condition causing localised, well demarcated patches of hair loss
50% patients hair regrows by 1 year
treatment of alopecia areata
topical or intralesional corticosteroids
topical minoxidil
phototherapy
dithranol
contact immunotherapy
wigs
features of tinea pedis
aka athletes foot - due to trichophyton fungi
typically scaling, flaking, and itching between the toes
tx - topical imidazole, terbinafine
features of basal cell carcinoma
most common type - nodular BCC
occurs in sun-exposed sites
pearly, flesh-coloured papule with telangiectasia –> ulcerate into central crater
management of basal cell carcinoma
surgical removal
curettage
cryotherapy
topical cream: imiquimod, fluorouracil
radiotherapy
