Dermatology Flashcards
Erythema multiforme - appearance, associations, treatment
Target lesions, face hands feet, systemically well (DDx: SJS/TENS). HSV, idiopathic, mycoplasma, TB, NSAIDs, penicillin, phenytoin. Remove trigger, support, emollient, potent steroid.
Ezcema herpeticum - appearance, symptoms, management.
Cluster of itchy painful blisters, may be purulent or bloodstained. Monomorphic and may have umbilication. Unwell - fever, lymphadenopathy. Take PCR swab and prompt antiviral treatment (rarely IV).
Erythema nodosum - appearance, associations, management.
Tests
Inflammation of subcut fat, painful, indurated. 50% idiopathic, inflam: IBD/sarcoid, infect: TB, beta haem strep, drugs: NSAID/OCP/amoxyl, pregnancy, ca: leuk/lymphoma. Resolve 2-3 weeks, elevate, compress, consider NSAID or pred.
If ix: FBE, UEC, ESR, throat swab, CXR, strep serology.
Actinic keratosis - appearance, significance, nonpharm treatment.
AKA sunspot, erythematous scaly lesions. Often Asx, rarely malignant but mean sun damage. Treat if bothersome. Cryotherapy w gun (avoid in legs for healing), + risk scar. Curretage or shave excision if thick. Derm for photodynamic therapy
What are the topical field treatment options for actinic keratoses?
Fluorouracil 4-5 (Efudix) or imiquimod 5% (Aldara), causes inflammation, review 2 weeks, takes 4 weeks. Not in pregnancy and sun. Alt: diclofenac gel, tretinoin cream.
Rosacea - features, associations, management principles.
30-50yo, warm w erythema + telangiectasia, papules, pustules but no comedones, men get rhinophyma. 50% get blepharoconjunctivitis. Triggers (sun, alcohol, spice). Gentle skincare, emollient, SPF. Eyelid hygiene + massage. Can’t cure
Rosacea - pharm treatment
1: topical ivermectin 4mo, 2/3: topical metro, azelaic acid. If moderate - oral doxy 100mg 2-4 weeks then 50mg 4 weeks (alt: erythromycin). Mirvaso topical 12hr treatment for flushing only, short term use. Laser for fixed vessels.
Topical steroids - formulations, potency examples, SE.
Cream less strong - wet area. Ointment - dry/scaly, avoid in folds. Lotions/solution for hair. Dermaid < aristocort < elocon < diprosone OV. SE: skin thin, stretch marks, telangiectasia, bruising, colour change, thicker hair.
Periorificial dermatitis - features, cause, treatment.
20-50yo, demarcated red base scaly, papules + vesicles. Rim around lips. Burning, itch. Fusobacteria growth. Steroids, idiopathic, cosmetics, OCP/pregnancy/premenstrual can risk. Rx: Zero therapy, cleanser only + add rosacea treatment (ivermectin, or metro + doxy or erythromycin).
Contact dermatitis - presentation, management.
Acute: vesicular, red, itch. Chronic: thick, scale fissures. Eg. interdigital or dribble rash. Mx: avoid triggers (sanitisers), avoid wetting, soap substitute, gloves, emollients frequently. Can use potent steroid 2-4 weeks.
Seborrheic dermatitis - features, symptoms, treatment.
Red + dry or greasy scale. Scalp, cheeks, nose, ?chest, blepharitis. Winter flare, low itch, no pustules. Skin cleanser, freq shampoo to reduce yeast. Scalp can: ketoconazole shampoo +/- elocon lotion for 1 week. Can increase. Non-scalp: hydrozole 2 weeks, otherwise advantan + canesten.
Cradle cap - self resolve, salicylic acid.
Sebaceous hyperplasia - appearance
Nodular, may be multiple and umbilicated. Sebaceous material with blurry telangiectasia not crossing midline.
Keratosis pilaris - features, symptoms, management.
Red bumpy spots - arms thighs, keratin accumulation in hair follice. Young people. Genetic. Dry/occasional itch. Avoid abrasives/picking. Emollients, avoid soap. Urea 10% topical, 2nd line tretinoin.
Grover disease - name, appearance, associations, management.
Transient acantholytic dermatosis. Sudden red papulovesicular itchy rash - trunk, upper arms. Assoc w sweat (fever, bed rest), older men. Reduce heat/humidity, emollient if dry, diprosone/aristocort for symptoms.
Impetigo - non-pharm and pharm management.
Cut nails, remove crust w bleach bath soak then wipe w wet cloth, wash clothes separate. Cover and school after 1st day treatment. Non-endemic and local: mupirocin 2% TDS 5 days. Non-endemic, lots: diclox/fluclox QID 1 week. (2nd: keflex or bactrim BD if allergy or MRSA).
Strep: benzathine benzylpenicillin STAT or bactrim.
Tinea - nonpharm and pharm management, 4 types and risk factors.
Avoid sharing towels, tight clothing, keep dry. Terbinafine D/BD 7-14 days (azoles 2nd line for 2-4 weeks). Oral if severe, recurrent or scalps/palms/soles. Cruris (RF: obesity, diabetes, sweating, immunosuppression). Pedis (animals, public shower, shared towels). Capitis - risk kerion, need oral. Manuum - rare, animals or objects.
Onychomycosis - features, management, followup
Thickening, onycholysis, discolouration. Take scrapings. Oral terbinafine 250mg daily until clinical clearance - monitor LFTs 4-6 week, caution alcohol. 3mo review, takes 9-12mo.
What are 7 risks of a skin biopsy?
Bleeding, infection, nerve injury, scarring, recurrence of lesion, wound breakdown, anaesthetic problem (vasovagal, allergy rare).
Psoriasis - risk factors/associations, general management.
RF: Fhx, drugs (lithium, beta blockers, NSAIDs), stress, smoking, pregnancy, koebner phenomenon (post cutaneous injury). Assoc CVD, gout, IBD. Moisturise. Tar + keratolytic safe, elocon for flare, steroid + calcipotriol (daivobet, enstilar) for body plaques.
Calcipotriol < 100g week, risk hypercalcaemia.
Psoriasis - presentation/mx at 6 different sites.
Scalp: elocon lotion, coal tar shampoo, enstilar. Face: steroids short term, 2%/2% tar/salicylic maintenance. Palmoplantar - more scaly, less red. Tar or daivobet or enstilar. Flexure - beefy red, shiny, less scale. Advantan, LPC 2% for control. Guttate: post strep, can be 6 mo. Nails: calcipitriol + beclomethasone or mometasone for 3mo.
Pityriasis rosea - features, mx, differentials.
Sick prior, herald patch, then days/weeks later patches plaques on tension lines - christmas tree. DIprosone or aristocort for itch. Self limiting in 6-10 weeks. DDx: drug allergy, guttate psoriasis, 2nd syphilis, viral exanthem, tinea.
Cyst near nails - name, management.
Digital myxoid cyst/pseudocyst. Smooth and shiny, jelly like substance inside. Often recur, can: press firmly, make hole w sterile needle, cryotherapy, surgically remove, inject steroid or sclerosant.
Pityriasis versicolor - cause, features, diagnosis, treatment.
Malassezia yeast, young adults in heat/humidity. Yellow green fluorescence on woodlamp, can do scrapings- hyphae/yeast, culture difficult. Shower after exercise, avoid sweat, topical econazole 1% or ketoconazole 2%. Not responsive - fluconazole 400mg PO stat. Colour takes time to resolve.
Features of oral lichen planus, hairy leukoplakia and discoid lupus.
LP: Wickham’s striae (striated), do biopsy. Hairy: from EBV, seen in HIV, benign but biopsy - border of tongue, parallel vertical white patches. DL: red centre, fine white sunray striations.
Oral candida - features, associations, treatment.
Creamy curd plaque/papules w red base (pseudomembranous), can be red alone. Immunocompromised, steroids, poor hygiene, dentures, abx use, smoking, HIV, diabetes. Amphotericin B or miconzaole. Nystatin - sugar.
Mouth ulcers - management, considerations.
Expect heal in 2 weeks, hydrocort 1% and difflam for symptoms, remove irritants (denture), antiseptic mouthwash. Review if not healing - biopsy, behcets disease.
Features/mx of geographic tongue, glossitis and hairy tongue.
Geo: loss of papillae in distribution, benign. Glo: complete loss in atrophic glossitis from dry mouth - smooth, red. Seen in coeliac, malnutrtion (B12, iron, folate). Hairy: hypertrophy of filiform papillae, black/brown. Assoc smoking/alcohol. Benign, use scraper.
Acne - nonpharm and 1st line management
Water based cosmetics/sunscreen, avoid picking, avoid hot/humid, avoid sunburn. Diet (low GI/dairy) in select cases. OTC BPO or salicylic acid. Then topical retinoid (adapalene) - introduce gradually at night, whole face, 6 week review.
