Clinical course of guttate psoriasis: long-term follow-up study.

Guttate psoriasis, known to have a better prognosis than other types of psoriasis, shows rapid involution and longer remission, but its clinical course has barely been studied. The aim of this study was to determine the clinical course and to compare the clinical and laboratory features of guttate psoriasis. This is a retrospective study of 26 patients with guttate psoriasis. The patients were divided into two groups; the good one with complete remission and long remission for at least 1 year (group A) and the poor one with incomplete remission and progression into chronic plaque psoriasis (group B). Among 36 patients, 22 patients (61.1%) were group A and 14 patients (38.9%) were group B. In group A, most of the skin lesions disappeared within 8 months. In group B, two patients without proper treatment progressed to plaque psoriasis. The onset age was younger and more frequent upper respiratory infection and high anti-streptolysin O (ASO) titer were found in group A, but family history of psoriasis was more common in group B. Patients had two distingushable clinical courses: rapid involuting course with long-term remission and chronic course without remission. There was a tendency toward younger age of onset with elevated ASO titer in patients with rapid involuting course.