Keratoses in patients with psoriasis: a prospective study in fifty-two inpatients.

Twenty-eight of 52 consecutive psoriasis inpatients admitted for therapy with the modified Goeckerman regimen had discrete, gray-white, asymptomatic, keratotic lesions approximately 4 mm in diameter at discharge from the hospital. In 18 of these 28 patients no keratoses were noted on admission. In 9 of 10 patients who had keratoses at admission, there was an increase in number at discharge. All patients with keratoses on admission had multiple, closely spaced previous admissions. No age, sex, or skin type predominance was evident in the group with keratoses compared with the remainder of the group (24 patients) who did not have keratoses. The development of keratoses was not related to the type or duration of psoriasis. Statistically significant predisposing factors were the number of UVB and PUVA treatments and the number of inpatient admissions. Fifty-two percent were located on the extremities, 33% on the trunk, and 15% on the face, head, and neck. Histologic examination of these lesions suggested that they may be a variant of seborrheic keratoses. We have not seen these lesions on patients receiving UVB, PUVA, or tar therapy for other diseases. This raises the possibility that these lesions may be unique to psoriasis and most likely are related to long-term therapy.