Phototests in Japanese patients with papulovesicular light eruption: positive provocation with UVA.

In six Japanese patients with papulovesicular light eruption (PVLE), photoprovocative tests were performed by irradiating UVA or UVB on the skin of the back on three consecutive days. One patient developed the typical lesion of PVLE at the test site with two consecutive daily irradiations of UVA. The remaining 5 patients had no abnormal phototest reactions. It was obvious that UVA plays an etiological role in at least some cases of PVLE.