Family MedicineAcademyWritten AKTNotesDermatologyInfections and infestations
Dermatology
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Asymmetrical erythematous scaly rash with an active leading edge.
Management: Skin scrapings for microscopy/culture when atypical, failed treatment, or before systemic therapy. Confirm nail fungus before oral treatment.
AKT pearl: Always look for a foot source when treating body or groin ringworm. Two feet, one hand is classic for tinea manuum/pedis.
Dermatophyte of feet/hands (red scale; feet may look dusty or macerated) and body/groin (annular plaque with scaly edge).
Management: Topical first-line: terbinafine once daily about 2 weeks, or miconazole/clotrimazole twice daily 2-4 weeks; continue 1-2 weeks after clearance for feet. Marked inflammation: add 1% hydrocortisone briefly with the antifungal. Severe, extensive, moccasin-type, or failed topical: oral terbinafine (alternatives: itraconazole; griseofulvin if others unsuitable). Body/groin: mild topical terbinafine 1-2 weeks; extensive/hairy/pustular/failed: oral terbinafine 250 mg once daily 2-4 weeks.
Advice: Feet/hands self-care: dry feet, daily sock change, air shoes, flip-flops in communal areas, hot-wash towels/socks.
Toenails more often than fingernails; thickening, yellow/white discoloration.
Management: No symptoms and mild: treatment optional. Mild (1-2 nails): amorolfine lacquer weekly 6-12 months, or tioconazole solution twice daily. Systemic preferred if severe/multiple: terbinafine 250 mg once daily (6 weeks fingers; 12-16 weeks toes). Itraconazole pulse is an alternative. Children: terbinafine or griseofulvin per local guidance.
AKT pearl: Oral terbinafine is first-line for Trichophyton rubrum nail infection after mycology confirmation.
Malassezia on trunk/shoulders: hypo-, hyper-, or pink macules with fine scale.
Management: First-line: ketoconazole 2% shampoo (short leave-on course) with or without selenium or imidazole cream. Extensive/recurrent: short oral itraconazole or fluconazole; consider monthly prophylaxis.
Scaly itchy scalp, patchy alopecia with or without erythema, pustules, lymphadenopathy. Kerion = boggy tender mass.
Management: Send hair/scale for mycology before treatment if possible. Systemic treatment is required. Empiric while awaiting culture: terbinafine for Trichophyton; griseofulvin for Microsporum (itraconazole if not tolerated). Adjunct: ketoconazole or selenium shampoo 2-3 times per week. Review 4-8 weeks after the course.
Advice: Screen family and pets; treat carriers with antifungal shampoo.
Red flags: Kerion (urgent), diagnostic uncertainty, paediatric treatment if not confident, failed treatment or complications.
Steroid-modified tinea (incognito) and tropical concentric tinea imbricata.
Features: Incognito: steroid use worsens/spreads tinea; less scale, more pustules. Imbricata: tropical concentric scaly rings.
Management: Incognito: stop steroid, scrape, then antifungal (topical if mild; oral if extensive). Imbricata: scrapings; oral terbinafine (or itraconazole); treat contacts and hygiene.
Fold dermatitis, often secondarily infected (candida or bacteria).
Risk factors: Obesity, diabetes, hyperhidrosis.
Management: Hygiene, zinc oxide barrier; treat infection (clotrimazole/miconazole for candida; erythromycin for erythrasma).
Highly infectious (S. aureus or S. pyogenes); common in children.
Features: Golden crusted lesions, often peri-oral.
Management: Localised: hydrogen peroxide 1% cream or topical fusidic acid/mupirocin. Extensive: oral flucloxacillin (or erythromycin if penicillin allergy).
Advice: School exclusion until crusted or 48 hours after starting antibiotics.
Corynebacterium minutissimum; well-demarcated pink-red or brown scale in folds (toe webs, groin, axillae).
Features: Coral-pink fluorescence under Wood lamp.
Management: Topical clotrimazole/miconazole; oral clarithromycin or erythromycin if extensive/resistant.
Chronic painful follicular occlusion in intertriginous areas; about 1-4% of the population; more common in women. Hurley stages 1-3.
Features: Recurrent nodules, abscesses, draining sinuses, scarring. Complications: sepsis, scarring, lymphoedema, SCC risk.
Management: Lifestyle: hygiene, loose clothes, stop smoking, weight loss. Topical antiseptics. Acute flares: steroids or flucloxacillin. Long-term antibiotics; surgery for persistent lumps.
Red flags: Severe disease, diagnostic doubt, or major psychological impact.
Folliculitis: inflamed follicles (often bacterial) causing red itchy/tender papules. Pseudofolliculitis: ingrown hairs from shaving; red bumps without true infection.
Management: Improve shaving technique; topical antiseptics (Dermol, chlorhexidine); topical/oral antibiotics (for example tetracycline) if persistent. Swab recurrent cases for nasal S. aureus carriage.
Itch is delayed hypersensitivity to mites/eggs.
Features: Intense itch and linear burrows (finger webs). Excoriation and secondary infection common. Crusted (Norwegian) scabies: massive mite load in immunocompromised or neurologically impaired patients; generalised scale, often less itchy.
Management: First-line: permethrin 5% cream (safe in pregnancy). Second-line: malathion 0.5%. Oral ivermectin for resistant cases. Apply whole body; leave 8-12 hours (permethrin) or 24 hours (malathion); repeat after 7 days. Crusted: oral ivermectin; isolation essential.
Advice: Treat all close contacts; wash bedding/clothing. Itch can last 4-6 weeks after successful treatment.
Common ages 4-11; head-to-head spread.
Features: Diagnose only if a live louse is found (nits alone are not enough).
Management: Treat affected household members. Wet combing or insecticides (dimeticone 4% lotion twice, 7 days apart). Pregnancy/breastfeeding: wet combing or dimeticone.
Poxvirus; direct contact/fomites; preschool children, especially with atopic eczema.
Features: Pearly papules with central umbilication. Usually self-limiting within about 18 months; routine treatment not needed.
Management: Troublesome lesions: squeeze/pierce, cryotherapy, or topical potassium hydroxide.
Advice: No school exclusion. Avoid sharing towels.
Red flags: Extensive lesions in HIV; eyelid margin; anogenital lesions (GUM for STI screen).
VZV reactivation; risk rises with age and immunosuppression.
Features: Unilateral dermatomal pain then vesicles; thoracic dermatomes most common. Complications: post-herpetic neuralgia (age-related); ophthalmic zoster (Hutchinson sign raises sight risk); Ramsay Hunt (facial palsy).
Management: Offer oral aciclovir 800 mg five times daily for 7 days if within 72 hours of rash, especially age over 50, non-truncal, or severe pain/rash. Analgesia including neuropathic agents as needed.
Advice: Infectious until all vesicles crusted; avoid non-immune contacts (pregnancy, immunocompromised, infants).
Red flags: Urgent admission for serious complications or severe immunosuppression. Urgent ophthalmology for ophthalmic zoster; ENT for Ramsay Hunt.
Related notesZoster complications overlap ENT Ramsay Hunt and dermatology shingles cards.Infections · shingles and skin infection
Related notesFacial palsy with vesicles in the ear canal is the ENT Ramsay Hunt card.ENT · Ramsay Hunt
HSV latency with reactivation (stress, illness). Peri-oral blisters.
Management: Usually self-managed with OTC topical antivirals and analgesia. Oral antivirals not routine in healthy people; consider for primary oral infection, severe/frequent recurrences, or immunocompromise.
Red flags: Urgent admission if unable to swallow or dehydrated. 2WW for unexplained oral ulceration lasting over 3 weeks. Specialist input for frequent severe recurrences or pregnancy near term.
Common, plantar, plane, anogenital types. Often resolve spontaneously.
Management: Salicylic acid, cryotherapy, curettage. Anogenital: self-applied podophyllotoxin first-line in non-pregnant adults; imiquimod 5% licensed for external genital/perianal warts; sinecatechins ointment also an option.
AKT pearl: Podophyllotoxin is a convenient self-applied first-line for uncomplicated anogenital warts in non-pregnant patients.