Minimal erythema dose (Med) to narrow band ultraviolet-B (NB-UVB) broad band ultraviolet-B (BB-UVB)--a pilot study.

Phototherapy is an effective treatment for various dermatological conditions. Ultraviolet B (290-320 nm) is reported effective in the treatment of psoriasis. Narrow band UVB (NB-UVB) is also reported effective in the treatment of psoriasis and vitiligo. To standardize the dosage schedule for NB-UVB we undertook this study to determine the minimal erythema dose (MED) on type IV and Indian skin. On six volunteers tested the MED for NB-UVB ranged between 150 mj and 400 mj and for BB-UVB ranged between 10 mj and 35 mj. The mean MED for NB was 300 mj and BB was 21 mj, the mean ratio of NB to BB was 1:15. We propose that narrow band UVB is a practical alternative to the conventional broad band UVB and has the advantage over photochemotherapy (PUVA) of being effective without prior administration of psoralen.