Dermatology

Dermatology is a high-yield AKT topic. Many questions include clinical descriptions or images and ask for diagnosis or management. Pattern recognition is important, but so is knowing the stepped treatment approaches for common conditions.

Eczema management follows a stepwise approach. Emollients are the foundation for all patients, applied liberally and frequently. Mild eczema: add mild topical corticosteroid (hydrocortisone 1%). Moderate eczema: moderate potency steroid (betamethasone valerate 0.025% or clobetasone butyrate). Severe eczema: potent topical corticosteroid (betamethasone valerate 0.1%). Face and flexures require lower potency. Tacrolimus (topical calcineurin inhibitor) is second-line for moderate to severe eczema, particularly useful on the face.

Psoriasis presents with well-demarcated erythematous plaques with silvery scale, typically on extensor surfaces, scalp, and lower back. First-line treatment is a potent topical corticosteroid combined with a vitamin D analogue (calcipotriol). Scalp psoriasis is treated with potent corticosteroid scalp applications. Refer if topical treatment fails or if psoriatic arthritis is suspected (NICE recommends rheumatology referral within 2 weeks).

Skin cancer recognition is critical. The 7-point checklist for pigmented lesions includes three major features (change in size, irregular shape, irregular colour) and four minor features (largest diameter 7mm or more, inflammation, oozing, change in sensation). Score 3 or more triggers a 2WW referral. Basal cell carcinomas present as pearly, telangiectatic nodules or non-healing ulcers. Squamous cell carcinomas present as keratinised nodules or non-healing ulcers on sun-exposed skin.

Acne treatment is stepped. Mild comedonal: topical retinoid (adapalene). Mild inflammatory: add topical benzoyl peroxide or topical antibiotic. Moderate: oral antibiotics (lymecycline or doxycycline for a maximum of 3 months) combined with topical retinoid. Severe or scarring: refer for consideration of isotretinoin. The teratogenicity of isotretinoin and the pregnancy prevention programme are commonly tested.

Fungal infections include dermatophyte infections (tinea corporis, pedis, cruris, capitis, unguium), candidal infections (oral thrush, vulvovaginal candidiasis), and pityriasis versicolor. Tinea capitis requires oral antifungal treatment (terbinafine or griseofulvin) and is common in children.