PUVA and PUVB in vitiligo--are they equally effective?

The combination of psoralens with different types of ultraviolet (UVL) sources in the treatment of vitiligo has led to different reports of success. The purpose of this trial is to compare in a random right-left comparison study the efficacy and side effects of oral 8-MOP plus UVA (PUVA) and oral 8-MOP plus UVB (broadband, 290-320 nm P-UVB) in the treatment of vitiligo.

The study included 24 cases of extensive vitiligo involving more than 30% of the body surface area in a bilateral symmetrical distribution. Each patient received 0.7 mg/kg 8-MOP orally 2 h before the light session. The right side of the body was exposed to UVA (320-400 nm), while the left half was exposed to UVB (290-320 nm). The patients received 3 sessions/week for a total of 30 sessions.

Both PUVA and PUVB produced moderate (50-60%) improvement, with similar incidences of phototoxic reaction and skin thickening. However, the study revealed a significant difference in the number of sessions needed to improve produce erythema and perifollicular pigmentation as well as a moderate response, the response on the UVA side always being earlier. Furthermore, the amount of joules needed to achieve the same response was 10 times greater on the UVA side than on the UVB side.

The use of psoralen plus broadband UVB is as effective as PUVA in the treatment of vitiligo. However, the long-term side effects of psoralen plus UVB are unknown.