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.
What are GP 2nd line options for acne?
Epiduo: BPO + adapalene for comedones. Duac: BPO + clindamycin for inflammatory. Acnatac: tretinoin + clinda for mixed. Doxy or erythromycin, COCP w cyproterone/drospirenone; spironolactone in nonpregnant women.
Dermatology role in acne - indication, SE, monitoring.
Severe impact, Fhx/Hx scarring, cystic nodular, persistent comedones. SE: flare of acne, sun sensitivity, chelitis, nosebleeds, dry skin. Check LFTs and lipids prior and during treatment.
Itch without rash - DDx(7), tests, management (nonpharm + pharm)
Scabies, dry, neuropathy, CKD, cholestasis, thyroid, haem malignancy. In older: FBE, UEC, LFT, TFT, BSL. NP: cool short shower, avoid soap, humidifier, emollients, short finger nails, avoid wool/synthetics. P: aristocort, antihistamine, doxepin if severe.
What are 2 types of drug eruptions? Management.
Morbilloform - penicillins, cephalosporins, NSAIDs, allopurinol. Emollient, topical steroid. Fixed drug eruption - well defined round red/violet plaque/patch/ulcer. Steroids + antihistamine.
Granuloma annulare - features, management.
Inflammatory condition on hands/feet in young people. Annular smooth, discoloured plaque or papule with active margin. No scale/itch mild tenderness. Biopsy to diagnose, self resolve, medium steroid if problematic.
What is intertrigo? Risk factors. What are 6 possible causes?
Rash in flexures. RF: diabetes, sweating, obesity, smoking, aclohol. Candida (itchy, moist, fast), tinea (slow, plaques, scale), erythrasma, psoriasis (well defined, smooth/red, symmetrical) , eczema, seborrheic dermatitis (poorly defined, salmon).
Erythrasma - appearance, diagnosis, treatment.
Well defined pink/brown patches in skin folds, coral pink on wood lamp. Minimal itch/flake. Corynebacterium. Fucidic acid/fusidate topical or 2nd Stat clarithromycin.
Pigmented nail lesion features
Subungal haemorrhage: peripheral globular structures, round w peripheral fading, linear white marks on plate. Trephinate if < 48hr. Melanoma: proximal nail affected, irregularly pigmented and width of bands, hutchinson - pigment in skin proximal to nail plate.
Urticaria - causes, management
Idiopathic, viral infection, allergy (food/sting/med) within 1-2hr, physical heat/exercise, dermatographism. Remove triggers, avoid heat, avoid NSAID. Antihistamine up to 4x dose if >12yo, consider montelukast, single dose pred. Doxepin in adults.
TENS/SJS - features, management
Febrile prodrome, skin and mucosal loss - peeling. Often antibiotic or anticonvulsant reaction within 1 month. TENS if >30% of BSA. Supportive care - IV fluid, temperature control.
Male/female alopecia treatments
Finasteride (low libido, gynaecomastia, possible prostate ca). Minoxidil vasodilator - eczema, seb derm, shedding, hypertrichosis. Females - midfrontal scalp, less temples. Minoxidil and/or spironolactone (No pregnancy, BP, UEC/LFT).
5 differentials for alopecia (non hormonal)
Telogen effluvium (stress, pregnancy, meds). Anagen effluvium (chemo). Alopecia areata - autoimmune patches affecting follicles, atrophic skin, !’s w thin base, 1 patch may recover 80%, use potent steroid or injections. Trichotillomania - bizarre pattern, anxiety/OCD. Tinea capitiis - red inflamed skin.
Hyperhidrosis - types, DDx, management.
Focal or generalised. Stress, thyroid,infection, cancer. Antiperspirant. Derm: iontophoresis, glycopyronnium, botox, systemic anticholinergic.
Keloid scar - differential, management.
Excess scar formation - firm, hard. Hypertrophic scar - pink, only at skin damage. Mx: intralesional steroid monthly, topical steroid often, silicone gel sheets or pressure dressings, cryotherapy.
Melasma - associations, management.
Sun exposure, pregnancy, OCP, Fhx, skin product/peel, thryoid disease. Sun protection, hydroquinone 2% 2-4mo 1st, tretinoin 2nd. Pulsated light therapy.
Vitiligo - features, management
Complete pigment loss, cause unknown. Associated w autoimmune diseases. Difficult to treat - better in kids. Diprosone or elocon, pimecrolimus on face/folds. Phototherapy by derm.
3 types of fibromas - features.
Neurofibroma (nerve sheath tumour) - solitary, soft, button-like, oval . Dermatofibroma (dermal fibroblasts) - firm, often pigmented, may itch, pinch sign- dimple. Don’t treat, surgery if wanted. Oral fibroma - irritated fibroma, benign scar reaction, benign.
3 types of lentigo’s
Ink spot/reticulated - symmetrical, flat wiry, won’t change. Solar lentigo/sun spot -precursor to solar keratosis, yellow/brown macule, consider lentigo maligna. Labial lentigo - labial melanocytic macule, well defined oval patch. If many, consider Peutz-jeghers GI polyps.
Lichen planus - features, management.
Purple, polygonal, pruritic, papules. Shiny, flat top from T-cells. Potent steroids. Can get oral form with lacey white lesions, risk SCC - biopsy, potent steroid to treat.
Black spots on heel - 2 differentials, management.
Talon noir - calcaneal petechiae, benign. Pitted keratolysis - pits and smell, from overgrowth of bacteria digesting keratin, moisture worsens. Manage sweat, antiseptic wash, can use clinda 1% lotion 10 days.
Scabies presentation and treatment
Nodular itchy, 4-6wk post exposure. Permethrin 5% neck down for 8hr , repeat in 1 week. Ivermectin oral w fatty food in rural, rpt 1 week. Treat family,vacuum furniture, wash clothes in 60 deg or store in sealed bag for 8 days, return to school after 1st treatment.
In babies/elderly in north australia, permethrin to face. Risk secondary infection, crusted scabies in RACF.
Bed bugs + lice management
BB - travellers, red migrating nodules, resolve spontaneously. Antihistamine or topical steroid. Lice - can be asx, wet combing, OTC treatments like dimethicone repeated in 1 week, treat house. 2nd line is ivermectin.
Seborrheic keratosis - appearance, differential, management.
Variable: flat, plaque, mm to cm, skin or brown or mixed. Stuck on. DDx flat - solar lentigo, lentigo maligna. Mx: cryo if thin, curettage, shave excision.
Pyogenic granuloma - features, management.
Fleshy, shiny red like healing wound. Surgery helpful, can do cyrotherapy, curretage and cauterise w silver nitrate, salt treatment, watchful waiting.
Morphoea and ichthyosis
M: thick/hard skin from inflammation, excess collagen. Localised slceroderma - derm review. I: chronic dry scaly skin, avoid drying, emollients, salicylic acid for scale.
3 types of folliculitis - features, management
Typical: warm compress, topical mupirocin 5d. Spa: pustular after water, may self resolve or need cipro for pseudomonas. Pseudofolliculitis - inflammation from short hair in follicle wall, moisturise/clean before shave, single blade razor, steroid cream or BPO or duac.
Terra firma-forme dermatosis + keratoderma
TFFD: keratinisation disorder, brown/back patches in young on flexures/neck, wipe w alcohol swab. DDx acanthosis nigricans. KD: chronic marked skin thickening, emollients and keratinolytics. DDx: psoriasis.
Callus and corn mx
Callus - thick skin, not painful. Corn is painful, has thick/dense core inside - can remove or use salicylic acid plaster.
Wart treatment options: 2 non-genital types
Plantar: topical saliclyic (40%) or cryotherapy 3x over 2-4 weeks. Surgery can spread warts. Plane/flat warts - often on face, 6-12mo resolve, topical tretinoin.
Hidradenitis suppuritiva - associations, treatment.
Chronic inflammation in sweat glands, nodules and abscesss form. Fhx, smoking, IBD, diabetes, obesity. Mx: loose clothing, topical antiseptic wash (BPO 5%), topical clinda 1% 3mo, doxycycline or erythromycin for antiinflammatory.
Molluscum contagiosum management in kids/adults
Virus in water - avoid baths, don’t share towels, wash hands. Resolve in 6-18mo. Tx risk pain/scar - curretage, cryo, tape for 24hr. Derm: cantharone. Adults - STI, self limit,same options + podophyllotoxin paint.
4 types of angiomas
Campbell de morgan spot: soft, red. Traumatised - black. Angiokeratoma - older, genitals. Spider angioma - blanching.
4 types of common naevi
Junctional (flat, pigmented), Dermal (raised, less pigment) + compound inbetween. Number and appearance vary in early life < 30yo. Congenital naevus - birthmark, sharp border, no change.
What is an atypical naevus and its significance
Naevi looking different or ABCDE features, can have multiple, may be more reddish than black. Mild dysplasia on histology (called dysplastic naevus then), benign. If >5, higher risk melanoma. Continuous monitoring.
5 special/rare type of naevi
Eclipse - compound on adolescent scalp, tan centre and brown rim, benign. Halo - flat w rim of depigmentation, benign in kids, excise in adult. Blue naevus - longstanding. Spitz naevus - classic is dome red/brown, solitary. Monitor in kids, remove in adults can be melanoma. Epidermal naevus - benign overgrowth of epidermis, lumpy string/patch.
Cheilitis - causes, associations, mx.
Atopy, contact dermatitis, infection (candida, strep), sun exposure. Remove trigger, can use mild/mod steroid. Angular chelitis - dentures not used or saliva issue OR nutrition or crohn’s - B12, folate, iron def.
Asteatotic eczema + erythromelalgia
Winter itch - older legs with dry skin and crazy paving. Moisturiser. EM: redness/burning and warmth extremeties, seen in polycythaemia and diabetes. Aspirin helps.
Ear nodule, milker’s nodule
Chondodermatitis nodularis helicis - on helix or antihelix, often from contact. Cryo or steroid inject (risk SCC). MN on hands: parapox from cows, blister like. Orf from sheep - greyish colour. Wear gloves to avoid contamination.
2 types of large inflammatory leg ulcers, associations, management.
Pyoderma gangrenosum: painful, raised purple undermined edge. Assoc: IBD, arthritis. Need derm for immunosuppression/pain/dressings, avoid surgery/debridement. Necrobiosis lipoidica - granulomatous lower leg plaques, yellow w telangiectasia, related to diabetes but not BSLs. Steroids.
Staph scalded skin syndrome - features, ddx, management.
Staph infection, fever, generalised red burn skin - tangential pressure causes exfoliation. DDx: SJS/TENS. IV fluid, antibiotics, analgesia. Good prognosis in kids, mortality in adults.
Glomus tumour and felon
GT: Painful tender, red/blue papule/nodule under nail or on palm. Benign, excise if bothersome. Felon: closed infection of fingertip pulp, abscess - oral abx, if tense need decompress as abx won’t get in - ringblock and cut midline.
Darier disease
Dyskeratosis follicularis, autosomal dominant and chronic. Yellow-brown keratotic papules on skin/chest, v-shaped cuts in nails. Need biopsy.
2 rashes from sun/outdoor exposure
Polymorphic light eruption - within hours of sun, itchy red papules/plaques/vesicles, fades in days, symptom relief w steroids. DDx: lupus, urticaria, photosensitive drug eruption. Phytophotodermatitis - itchy rash after fruit/plant + sun
