METHODS: Review of hospital case notes on patients with juvenile GPP.

RESULTS: Twenty-seven patients with juvenile GPP were identified. Female to male ratio was 1.4:1. The median age at onset of GPP was 6.5 years. Ten patients had prior psoriasis with a median pre-pustular duration of 2.7 years. Onset of GPP was earlier in patients without prior psoriasis (5.1 years vs. 12.0 years, P = 0.002). Precipitating factors identified included stress, upper respiratory tract infection, systemic steroid use, vaccination, and pregnancy. A positive family history of psoriasis and GPP was present in six and one patient(s), respectively. Twenty-one patients had acute, five annular, and one localized variant of GPP. Arthritis was present in 22.2%. Fever, leukocytosis, and transaminitis were mainly seen in patients with acute GPP at 80.9, 72.2, and 11.1%, respectively. Among 20 patients screened, eight carry IL36RN variants and one has CARD14 mutation. IL36RN-positive patients have more severe disease characterized by early onset, low prevalence of prior plaque psoriasis, high prevalence of systemic inflammation, and need for continuous long-term systemic therapy. Acitretin and cyclosporine were effective in aborting acute GPP in 100% of 16 and 66.7% of six patients treated, respectively. However, relapses were common. Only three of the 17 patients whose initial acute GPP was controlled with systemic agents were successfully weaned off treatment.