Civatte first described the condition in 1923. [6] We propose that photoallergic contact dermatitis from 6-methylcoumarin may have played a role in producing poikiloderma of Civatte in this patient.

The patch-test result was negative, but the photopatch-test result showed photoallergic contact dermatitis from 6-methylcoumarin (++ reaction) and usnic acid (+ reaction) on the irradiated side ...