Diclofenac-induced pseudoporphyria; an under-recognized condition?

Pseudoporphyria is a photodistributed bullous disorder that is clinically and histologically similar to porphyria cutanea tarda (PCT), but without abnormal porphyrin biochemistry. Renal failure, dialysis, excessive ultraviolet A and medications, particularly nonsteroidal anti-inflammatory drugs (NSAIDs), have been associated with pseudoporphyria. We report a case of diclofenac-induced pseudoporphyria in a man with psoriatic arthritis. To our knowledge, this is only the second reported case of pseudoporphyria associated with diclofenac. Diclofenac has hitherto been considered by many dermatologists as a safe alternative in NSAID-induced pseudoporphyria.