Psoriasiform skin changes have been rarely described in the literature in both acute (1-4 weeks) and convalescent phases (4-12 weeks) of KD (1).
Haddock et al, in their review of 870 cases of KD, identified 11 patients with a psoriasiform eruption (1.3%). The authors compared these cases in a 1:2 ratio to KD with classic psoriasis and KD without psoriatic lesions, respectively. Only 2 cases appeared in the acute phase of the illness; the median time of appearance was on day 22 of illness. Clinically, 9 presented as plaques, 1 as guttate psoriasis, and 1 as nail psoriasis. Compared to typical pediatric psoriasis, the psoriasiform eruption of KD had more serous crusting and less diaper involvement. Histologically they were virtually identical, as were the genetic studies of the late cornified envelope genes. Three of the cases were treated with infliximab. Ten of the 11 cases (91%) resolved within 18 months, compared to only 23% of the classic psoriasis group, a statistically significant finding. The presence of the psoriasiform eruption did not adversely affect KD outcome (2).
This is an important article reminding us to recognize a rare phenomenon – the presence of a psoriasiform eruption during, and most typically following, the acute phase of KD. This is a stressful time for parents as their children confront a potentially life-threatening disease that warrants systemic treatment, typically with IVIG, aspirin, and increasingly infliximab. The latter could possibly contribute to the pathogenesis of the psoriasiform eruption in some patients with KD (3). While much remains to be learned regarding the pathogenesis and ultimate prognosis of this psoriasiform eruption (will these patients be at risk for psoriasis later in life?), in the short term, parents may take solace in knowing that for the vast majority the prognosis is excellent.
- Ergin S, et al. Plaque psoriasis induced after Kawasaki disease. Turk J Pediatr 2009; 51: 375-7.
- Haddock ES, et al. Psoriasiform eruptions during Kawasaki disease (KD): A distinct phenotype. J Am Acad Dermatol 2016; 75: 69-76.
- Kishimoto S, et al. Psoriasiform skin lesion and suppurative acrodermatitis associated with Kawasaki disease followed by the treatment with infliximab: A case report. Acta Paediatr 2010; 99: 1102-4.