Psoriasiform eruptions during Kawasaki disease (KD): A distinct phenotype.

Abstract

A psoriasis-like eruption develops in a subset of patients with Kawasaki disease (KD). We sought to systematically compare KD-associated psoriasiform eruptions with classic psoriasis and the outcomes of KD in children with and without this rash. This was a retrospective study of 11 KD cases with a psoriasiform eruption matched 1:2 by age, gender, and ethnicity with psoriasis-only and KD-only controls. Genotyping was performed in 10 cases for a deletion of 2 late cornified envelope (LCE) genes, LCE3C_LCE3B-del, associated with increased risk for pediatric-onset psoriasis. Similar to classic psoriasis, KD-associated eruptions were characterized clinically by well-demarcated, scaly pink plaques and histopathologically by intraepidermal neutrophils, suprabasilar keratin 16 expression, and increased Ki-67 expression. They showed less frequent diaper area involvement, more crust and serous exudate, and an enduring remission (91% vs 23% with confirmed resolution; P < .001). Frequency of LCE3C_LCE3B-del and major KD outcomes were similar between cases and controls. The study was limited by the small number of cases, treatment variation, and availability of skin biopsy specimens. Although the overall clinical and histopathologic findings were similar to conventional psoriasis, this appears to be a distinct phenotype with significantly greater propensity for remission. No adverse effect on KD outcomes was noted.