In case no. 2, the pathogenic mechanism seemed to be persistent light reaction preceded by systemic photoallergy, as he had taken mequitazine for 6 months, and there were strong positive photopatch test results with immediate erythema reaction, cross-reaction to promethazine, decreased MED to both UVA and UVB, and persistence of the photosensitivity over a 3-year follow-up period after discontinuation of the mequitazine.
persistence of the photosensitivity
promethazine
cross-reaction to promethazine
promethazine
erythema
promethazine
cross-reaction to promethazine
mequitazine
persistence of the photosensitivity
mequitazine
erythema
mequitazine
decreased MED to both UVA and UVB
mequitazine
decreased MED to both UVA and UVB
promethazine