Psoriasis in children — branching viva

Opening question

Examiner: Take me through this child. What is the diagnosis, and what is your frame for managing it? ^[1]

Candidate: The most likely diagnosis is chronic plaque psoriasis — the thick, well-demarcated, scaly patches on the extensor elbows, knees and scalp, with nail pitting and a father with psoriasis, are the classic picture of the commonest form of childhood psoriasis. My frame is three-layered: match the treatment to the severity and quality-of-life impact, screen the comorbidities that travel with psoriasis, and build a long-term partnership with the family because this is a chronic relapsing disease. Because she is otherwise well with limited sites, this begins with topical therapy and a comorbidity screen, with escalation if the disease or its impact grows. ^{[1] [2]}

Examiner: How do you classify paediatric psoriasis, and how does it differ from the adult disease? ^[2]

Candidate: By lesion shape and site. Chronic plaque psoriasis is the commonest — well-demarcated erythematous plaques with silvery-white scale on the extensor surfaces and scalp, with the Auspitz sign of pinpoint bleeding and Koebner phenomenon where plaques arise in lines of trauma. Acute guttate psoriasis is the other classic form — small droplet papules across the trunk one to two weeks after streptococcal pharyngitis. Children differ from adults: the face is involved more often, the scalp is a frequent first site, and infants can present with napkin or diaper-area psoriasis. Nail and scalp involvement are common, and I would examine all of these. ^{[2] [3]}