Photoallergic drug eruption due to pyridoxine hydrochloride.

Photoallergy to vitamin B6 is very rare; only a few cases of contact dermatitis and one case of photosensitive dermatitis due to pyritinol have been reported. We report here the first case of photoallergic drug eruption due to pyridoxine hydrochloride. A 71-year-old man developed papulo-squamous erythemata which were confined to sun-exposed sites. Photopatch testing, together with the clinical course, was helpful in reaching the initial diagnosis; this was confirmed by an oral challenge test. Photoallergic drug eruption due to vitamin B6 should be considered a rare cause of photosensitive dermatitis.