Plasma levels of 8-methoxypsoralen after topical paint PUVA

Topical PUVA therapy has become a useful alternative for patients who cannot tolerate the systemic side effects of nausea and headache or are concerned about the ophthalmologic risk associated with oral PUVA therapy. However, there is no study to date on the systemic absorption of psoralen after the localized application of topical paint PUVA.

This study was designed to assess the plasma level of 8-methoxypsoralen (8-MOP) after paint PUVA therapy for patients with palmoplantar psoriasis or eczema.

Reverse-phase high-pressure liquid chromatography was used to determine 8-MOP plasma levels in eight patients with palmoplantar psoriasis and two with eczema. Three patients receiving oral PUVA therapy served as the control group.

Plasma levels of 8-MOP taken 1, 6, and 24 hours after topical PUVA treatments of patients with palmoplantar psoriasis were undetectable. One patient with hand eczema consistently had detectable 8-MOP levels 1 hour after topical PUVA treatments.

This report indicates that there is minimal, if any, systemic absorption of 8-MOP after topical PUVA treatment of patients with palmoplantar psoriasis.