Derm Flashcards
Treatment of scalp psoriasis?
Potent steroids for 4 weeks
If no improvement, consider using something to break up adherent scale (salicylic acid/oils) and a different formulation of potent steroid (shampoo/mousse)
Red papule with surrounding capillaries which blanch on pressure?
Causes?
Spider naevi
Liver disease, COCP, pregnancy (increased oestrogen)
Acne treatment ladder?
- topical retinoid/benzoyl peroxide
- Combination topical therapy - retinoid/benzoyl peroxide/abx
- Oral antibiotic - tetracycline (or erythromycin in pregnancy, breastfeeding, young) WITH topical retinoid or benzoyl peroxide - at least 3 months
- WOMEN only - COCP or co-cyrindiol (dianette) - increased risk of VTE compared to COCP, 3 months max
- Oral isotretinoin
3 types of BCC?
typical description?
Type of referral?
Management options?
Nodular, superficial, infiltrative
Pearly skin coloured papule with telangiectasia which ulcerates in centre, with picket fence border
Routine referral
Leave alone
Surgical removal - conventional or Mohs
Topical: imiquimod/5-FU
Atopic eczema distributon in infants vs children and adults?
Yellow, weeping crust over eczema?
infants - face and extensor surfaces (napkin area and flexural surfaces spared)
Older - flexural surfaces esp wrist, cubital fossa, popliteal fossa and ankles
GAS infection
Most common cause of erisypelas?
When is Rx given IV?
Strep Pyogenes
Facial - cavernous sinus drainage - need to avoid
Also give IV if Staphylococcal Scalded Skin Syndrome
Apart from shins, where else can erythema nodosum happen?
Causes?
How long to heal?
Forearms, thighs
No cause (60%) Infection - strep, TB Sarcodosis IBD Behcet's Malignancy Pregnancy Drugs - penicillins, COCP
Heals in 6 weeks without scarring
Keratoacanthoma?
Management?
Benign epithelial tumour more common in elderly
initially smooth dome-shaped papule that rapidly grows to become a crated centrally filled with keratin
Spontaneous regression within 3 months but scars. However, should be excised immediately to rule out SCC - this also prevents scarring
5 types of melanoma?
Superficial spreading - long radial growth phase, most common
Nodular - straight into vertical growth phase, bad prognosis
Acral lentigous - on palms/soles/subungal
Amelanotic - no pigment
Lentigo maligna - melanoma in-situ - very slowly progressive but may at some stage develop into malignant
Management of suspected melanoma?
Exception?
Excision biopsy - remove entire lesion
Lentigo maligna - can be large - take biopsies from darkest areas - topical imiquimod can give histological clearance
Breslow thickness relation to and excision margins?
<1mm - 1cm
1-2mm - 2 cm
2-4mm - 2-3cm
> 4mm - 3cm
<1mm = >95% 5-year survival >4mm = <50%
Most molluscum contagiosum can just be left - when is referral needed? (3)
HIV with extensive lesions - HIV specialist
Eyelid margin or ocular - ophthalmologist
Adults with Anogenital - GUM to ensure it’s not something else
What vitamin deficiency causes pellagra?
What drug can cause it?
B3 - niacin
(3D’s - dermatitis, diarrhoea, dementia/depression)
Isoniazid - stops the conversion of tryptophan to niacin
Most common in alcoholics
Nail changes in psoriasis? (4)
Present in 80-90% with arthropathy
- Pitting
- Onycholysis
- Subungal hyperkeratosis
- Loss of nail
Pyoderma gangrenosum?
Initially small red papule, develops into deep, red, necrotic ulcer with violaceous border
Idiopathic 50%
Assoc w IBD, SLE, RA, blood cancers and PBC
Oral steroids
Pyogenic granuloma?
Who in?
Management?
Usually after trauma in young/pregnant women
Initially small red/brown spot, within days-weeks is raised spherical lesion, may bleed profusely or ulcerate (haemangioma)
Oral mucosal lesions common in pregnancy
Pregnancy-assoc spontaneously resolve post-partum
Otherwise, curettage and cauterisation
What drugs CANNOT be prescribed with isotretinoin and why?
Tetracyclines - raised ICP
Purple cutaneous nodule in immunosuppressed pt?
Kaposi sarcoma
When might shingles cause facial palsy?
Ramsay Hunt Syndrome
Ear lesions and facial paralysis, can cause vertigo and deafness as well
Excision margins for SCC?
If <2cm - 4mm margins
If >2cm - 6mm margins
Mohs microsurgery in high-risk pts or cosmetically important sites
Strawberry naevus progression?
If Rx required eg blocking visual field?
Capillary haemangioma
Not present at birth, usually develops rapidly in first month of life
Increases in size until about 6-9 months, then starts to regress. 95% resolve by 10 years of age
May bleed, ulcerate or obstruct visual fields
If Rx required:
- Propanolol
- Topical timolol
- Oral steroids
Which HPV viruses cause: - warts? - genital warts? - oral and cervical cancer? Treatment of warts?
Warts: 1-4
Genital warts: 6/11
Cancer: 16/18/33
Rx: Salicylic acid, cryotherapy, podophyllum, imiquimod
Podophyllum/cryotherapy 1st line genital
Porphyria cutanae tardis presentation?
Enzyme deficiency?
Woods lamp?
Middle aged men, common with liver disease (alcohol, hep, cirrhosis, haemochromatosis)
Blistering lesion on sun exposed sites that heal with scarring and hyperpigmentation
Uroporphyrinogen decarboxylase
Shines pink instead of blue
Erythropoeitic porphyria presentation?
Enzyme deficiency?
AD disorder seen in children
May be no rash but will be painful burning and itching when exposed to sun - kid may scream in sun
Ferrochealatase
Junctional vs compound naevi?
Junctional = flat
Compound = raised
Widespread sunburn-like rash over body, including lips, with fever and sepsis?
What can cause this in women?
Staph toxic shock syndrome
Tampon use
