Dermatology Flashcards
What are the features of pityriasis rosea?
- majority no prodrome, some recent hx of viral infection
- herald patch (usually trunk)
- followed by erythematous, oval, scaly patches following a characteristic distribution with the longitudinal diameters of the oval lesions
- parallel to lines of langer
- may produce a ‘fir-tree’ appearance
What are the features of lichen planus?
Planus:
Purple
Pruritic
Papular
Polygonal rash on flexor surface
(Wickhams striae over surface)
(Oral involvement common)
Can occur site of scars etc (koebner’s response)
What’s the management of lichen planus?
Potent topical steroids
Benzydamine mouthwash or spray for oral
How does eczema herpeticum present?
Children with existing eczema
Rapidly progressing painful rash - monomorphic punched out erosions
what are the causes of acanthosis nigricans?
- t2dm
- gastrointestinal cancer
- obesity
- PCOS
- acromegaly
- cushing’s disease
- hypothyroidism
- familial
- prader-willi syndrome
- drugs
> COCP
> nicotinic acid
what are the causes of erythema nodosum?
- infection
> strep, tuberculosis, brucellosis - systemic disease
> sarcoidosis, IBD, Behcet’s - drugs
> penicillins, sulphonamides, COCP - pregnancy
management options for SCC?
- excision with 4mm margins for lesion <20mm
- excision with 6mm margins for lesion >20mm
- mohs micrographic surgery for highrisk pts and in cosmetically important sites
what is intra-epidermal squamous cell carcinoma?
Bowen’s disease
what is the management for intra-epidermal SCC/bowen’s disease?
topical 5-fluorouracil
what is the management for urticaria?
1L: non-sedating antihistamines
2L: prednisolone used for severe or resistant episodes
how is contact dermatitis investigated?
patch testing
what nail changes are seen in psoriatic arthropathy?
pitting
onycholysis (separation of nail from nail bed)
subungual hyperkeratosis (chunky)
loss of the nail
What is the management for dermatophyte nail infections?
Oral terbinafine
What is the first line management for acne vulgaris?
Topical combination therapy (eg adapalene and benzoyl peroxide for mild-mod, or topical tretinoin and topical abx)
What complication does psoriasis put you at higher risk of?
Cardiovascular disease
What are the causes of stevens johnson syndrome?
Penicillin
Sulphonamides
Lamotrigine, carbamazepine, phenytoin
Allopurinol
NSAIDs
Oral contraceptive pill
how long should the break be between courses of topical steroids?
4 weeks
management for fungal nail infections?
if limited involvement - topical amorolfine 5% nail lacquer
if more extensive (mod-sev) - oral terbinafine for 6weeks-3months
what is the management for venous ulceration?
- compression bandaging
- oral pentoxifylline (peripheral vasodilator)
features of dermatitis herpetiformis?
itchy vesicular skin lesions on extensor surfaces
dx of dermatitis herpetiformis?
skin biopsy
antibodies associated with dermatitis herpetiformis?
anti-ttg
-> associated with coeliac
where is venous ulceration most commonly seen?
above the medial malleolus
what are the 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
scabies mgt?
two treatments with permethrin one week apart for patient and all close contacts
nail signs seen in psoriatic arthritis?
pitting
onycholysis
subungual hyperkeratosis
loss of nail
first line mgt in rosacea with severe papules and/or pustules?
topical ivermectin and oral doxycyline
features of pityriasis versicolor?
most commonly affects trunk
patches may be hypopigmented, pink or brown (hence versicolor).
May be more noticeable following a suntan
scale is common
mild pruritus
malignancy most common secondary to immunosuppression?
skin cancer -squamous cell carcinoma
first line management of psoriasis?
topical corticosteroid
vitamin D analogue
management of pityriasis versicolor?
ketoconazole shampoo
first line mgt mild/moderatre rosacea?
topical ivermectin
features of bullous pemphigoid?
itchy tense blisters around flexures
blisters heal without scarring
stereotypically no mucosal involvement
most important prognostic factor in melanoma?
invasion depth of the tumour
what is koebner phenomenon?
skin lesions that appear at the site of injury
which conditions is koebner phenomenon associated with?
psoriasis
vitiligo
warts
lichen planus
lichen sclerosus
molluscum contagiosum
mgt of dermatitis herpetiformis?
IV aciclovir (admission)
features of takayasu’s arteritis?
systemic vasculitis features eg malaise, headache
unequal BP in upper limbs
carotid bruit and tenderness
absent or weak peripheral pulses
upper and lower limb claudication on exertion
aortic regurg
investigations for takayasu’s arteritis?
vascular imaging of arterial tree - MRA or CTA
management for takayasu’s arteritis?
steroids
what is erythema nodosum?
inflammation of subcut fat
features of erythema nodosum?
tender, erythematous, nodular lesions
usually over shins, may occur elsewhere
causes of erythema nodosum?
infection - strep, TB, brucellosis
systemic dx - sarcoidosis, IBD, behcets
malignancy/lymphoma
drugs - penicillins, sulphonamides, COCP
pregnancy
features of alopecia areata?
localised, well demarcated patches of hair loss
-> regrows in 50% by one year, and 80-90% eventually
mgt options for alopecia areata?
topical or intralesional steroids
topical minoxidil
phototherapy
dithranol
contact immunotherapy
wigs
causative organism of pityriasis versicolor?
malassezia furfur
features of seborrheic dermatitis?
eczematous lesions on sebum rich areas - scalp, periorbital, auricular and nasolabial folds
otitis externa and blepharitis may dvlp
conditions associated with seborrheic dermatitis?
HIV
Parkinsons
causes of koebners phenomenon mnemonic?
previous wounds lead 2 various marks
Psoriasis
Warts
Lichen planus/sclerosus
Vitiligo
Molluscum contagiousum
mgt for impetigo?
localised:
hydrogen peroxide 1%
topical abx if hydrogen peroxide not suitable:
fusidic acid
mupirocin if fusidic acid resistance
extensive dx: oral fluclox
oral erythromycin if pen allergic
name for invasion depth of a melanoma?
breslow depth
when is referral necessary in molluscum contagiosum?
HIV positive - ref to HIV specialist
eyelid-margin or ocular lesions and red eye - ref to ophth
adults with anogenital lesions - ref to GUM
features of pyoderma gangrenosum?
initially small red papule
-> later deep, red, necrotic ulcers with violaceous border
what is a curlings ulcer?
stress ulcers in duodenum of burns patients
more common in children
mnemonic for drugs that worsen psoriasis?
psoriasis gives you blanc plaques
Beta blockers
lithium
alcohol
NSAIDs
Quines (hydroxychloroquine etc)
