A comparison of systemic photochemotherapy with 8-methoxypsoralen (8-MOP) and with trimethylpsoralen (TMP) in vitiligo

Oral 8-MOP and TMP were compared in the PUVA therapy for vitiligo. Group A (25 cases) was initiated on 0.3 mg/kg of 8-MOP with 1/2 Joule/cm2 of UVA and weekly increments of 1/2 Joule/ cm2 and Group B was started on 0.6 mg/kg of TMP with 1 Joule/cm2 of UVA and weekly increments of 1 Joule/cm2. Therapy was given thrice a week. Repigmentation was evaluated by using a 0-6 scale. At the end of 60 sittings, on acceptable cosmetic response was seen over the face, neck and upper extremities in both groups, while trunk and lower extremities showed lesser response. 8-MOP gave earlier response, needing a lower cumulative UVA dose i.e. 75 J/cm2 as compared to TMP i.e. 106 J/cm2. Phototoxicity was seen more often with 8-MOP. In conclusion, in Indians, 8-MOP is the drug of choice in PUVA therapy of vitiligo provided precautions against phototoxicity are adequate.