Two Cases of Photosensitive Psorasis / 대한피부과학회지

ABSTRACT

Photosensitive psoriasis is a rare disease defined as psoriasis in which the lesions deteriorate or new lesions develop after sun exposure. It should be differentiated from other photosensitive conditions that may be a vated or confused on sun-exposure. Half of the patients have a history of polymorphic light eruption(PMLE), whieh several weeks later develops into psoriasis lesions and the others have no history of preceding PMLE reaction. PUVA therapy is recommended for the treatment of choice. In this report, we describe two cases of photosensitive psoriasis. A 51-year-old woman without underlying psoriasis suffered from erythemato-squamous papular lesions on the face, neck and dorsum of hands after sun-exposure. She revealed a lowered minimal erythema dose(MED) for UVA which was confused with a photosensitive disease. But characteristic psariatic plaques on the elbow, knee and palm and histologic findings made the diagnosis photosensitive psoriasis. She showed a good result to cyclosporine therapy. The other patient, a 44-year-old woman with underlying psoriasis, experienced an exacerbation with preceding PMLE and showed a lowered erythema threshold for UVB. She was treated with sun-screen and topical corticosteroids.