Allergic contact dermatitis due to 8-methoxypsoralen(8-MOP)

Lee, In Joon; Park, Yoon Kee; Im, Sungbin; Hann, Seung Kyung

Abstract

Allergic contact dermatitis due to 8-MOP is a rarely known si(ie effect of this widely used drug. Other known adverse reactions due to 8-MOP such as the oallergic dermatitis as well as some isolated cases of exanthema, papular eruptions, and astloma like symptoms are also sporadically reported. A 52-year-old man with vitiligo developed erythema to the UVA exposed 0.3% Oxoralen cream applied area. Prior to this episode, the patient had history of generalized burns after systernic PUVA therapy in 1983. Even after this experience, the patient had few more episodes of erythema at the site of 0.3%. Oxoralen cream application. We performed patch test and photopatch tests with Scandinavian series, 0.3% Oxoraler or am (as is), and diluted 8-MOP, 5-MOP, TMP solution. The result showed positive reactivity to 6-methylcoumarin, 8-MOP, as well as to 0.3% Oxoralen cream. The size of erythema was same in both irradiated areas which indicates an allergic contact dermatitis rather than photoallergic dermatitis or phototoxic dermatitis.