['Lymphocytic infiltration of the skin (LIS) is a disorder in which photosensitivity has been suspected but never proven.', 'To carry out a systematic photobiological investigation in patients with LIS and to compare the photobiological features of LIS with those of other photosensitive disorders.', 'We performed provocative phototesting with ultraviolet (UV) A and UVB in 10 patients with active LIS.', 'In all patients, UVA and/or UVB elicited abnormal papular phototest reactions resembling lesions of LIS both clinically and histologically. Lesions typically developed 3--6 days (mean +/- SD 100.8 +/- 20.9 h) after the first UV exposure.'] Is lymphocytic infiltration of the skin a photosensitive variant of lupus erythematosus : evidence by phototesting?