COEUR D’ALENE, IDAHO – The psoriasiform eruptions that occur in a subgroup of patients with Kawasaki disease during the acute or subacute phase may be a red flag for more severe coronary artery involvement, according to a retrospective, case-control study.
Another striking feature of these psoriasiform lesions is that they go into remission. No recurrences were seen in the study population during up to 13 years of follow-up, in marked contrast to classic psoriasis, a chronic disease, Dr. Wynnis L. Tom observed at the annual meeting of the Society for Pediatric Dermatology.
Dr. Wynnis L. Tom
She presented what she believes to be the first study to formally compare the psoriasiform lesions arising in a minority of Kawasaki disease (KD) patients with the lesions of classic psoriasis. The study population consisted of 11 KD patients with psoriasiform eruptions whose median age was 1.9 years, 22 matched controls with KD and no psoriasiform lesions, and another 22 matched controls with psoriasis but not KD.
Kawasaki disease patients who developed psoriasiform eruptions had significantly more dilated coronary arteries than did those who did not, as reflected in their median maximal echocardiographic z-score of 2.7, compared with 1.8 in controls. A z-score greater than 2.5 is deemed to indicate clinically significant coronary artery dilation, noted Dr. Tom, a pediatric dermatologist at Rady Children’s Hospital and the University of California, San Diego.
The psoriasiform eruptions resolved within 13 months in all 11 affected KD patients, with no recurrences. In contrast, only 5 of 22 controls with classic psoriasis experienced remission during follow-up of up to 6 years.
The cutaneous distribution of the psoriasiform lesions in patients with KD was also distinctive. The eruptions were significantly less common in the head, neck, and diaper area than is the case in classic psoriasis. In addition, patients with KD and psoriasiform eruptions were significantly less likely to be overweight or obese than were controls with classic psoriasis.
Skin biopsies read by a blinded dermatopathologist showed that the psoriasiform lesions that arose during KD demonstrated suprabasilar staining of keratin 16 and increased expression of Ki-67 antigen. They differed from classic psoriasis lesions in that they displayed more crusting, serum, and an increased prevalence of bacteria at the epidermis.
There was no significant difference between KD patients with and without psoriasiform eruptions in terms of maximum levels of C-reactive protein, erythrocyte sedimentation rate, and other inflammatory markers. However, patients with psoriasiform lesions required significantly more time for their gamma-glutamyl transferase level and platelet count to return to normal.
One possible explanation for the distinct phenotype of these psoriasiform eruptions is that KD brings forth the skin lesions in patients who are predisposed to psoriasis, but without causing typical chronic psoriasis because the underlying KD is self-limited. But further study with larger numbers of patients is required for clarification, according to Dr. Tom.
Her work is supported by a career development award from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. She reported having no financial conflicts regarding this study.