Chronic immune-mediated inflammatory skin disorder with well-demarcated erythematous plaques and silvery scale.
Risk factors
- • FHx (HLA-Cw6)
- • Stress, smoking, alcohol
- • Streptococcal pharyngitis (guttate)
Clinical features
- • Itchy scaly plaques on extensors, scalp
- • Nail pitting, onycholysis
- • Joint pain (psoriatic arthritis)
Investigations
- • Clinical
- • Skin biopsy if atypical
Diagnosis
- • Auspitz sign, Koebner phenomenon
Differential diagnosis
- • Eczema
- • Lichen planus
- • Tinea corporis
- • Mycosis fungoides
Management
- • Emollients
- • Topical steroid + vitamin D analogue (calcipotriol)
- • Phototherapy (NB-UVB)
- • Systemic: methotrexate, ciclosporin, biologics (anti-TNF, IL-17, IL-23)
Drug therapy
- • Betamethasone 0.05% + calcipotriol gel daily
- • Methotrexate 7.5–25 mg weekly + folic acid
Complications
- • Psoriatic arthritis
- • Cardiometabolic disease
- • Erythroderma
Clinical pearls
- • Screen for PsA annually (PEST questionnaire)
Related in WardRound
Educational — verify locally.
