Pseudoporphyria Associated with Nonhemodialyzed Renal Insufficiency, Successfully Treated with Oral N-Acetylcysteine

Pseudoporphyria (PP) is a relatively rare, photodistributed bullous dermatosis that resembles porphyria cutanea tarda (PCT), but it is not accompanied by porphyrin abnormalities in the serum, urine, or stool. It was initially described in renal failure patients on dialysis. Thereafter, it has been associated with several aetiological factors. We report a case of PP in a 67-year-old woman with mild renal failure, successfully treated with N-acetylcysteine. This is the second reported case of PP developing in nondialyzed chronic renal failure. Such cases support the view that renal impairment itself may play a more important aetiological role in developing PP than it was originally considered. 1. Introduction Pseudoporphyria (PP) is a relatively rare, photodistributed bullous dermatosis that clinically, histopathologically, and immunologically resembles porphyria cutanea tarda (PCT), but it is not accompanied by porphyrin abnormalities in the serum, urine, or stool. It was initially described in patients with renal failure on dialysis as “bullous dermatosis of hemodialysis” [1]. Subsequently, PP has been associated with numerous photosensitizing medications, hormone replacement, UVA radiation in tanning beds, hepatitis C, sarcoidosis, Sjogren syndrome, hepatoma, HIV infection, and lupus erythematosus. In a retrospective study of 20 cases, the mean age at diagnosis was 50 years [2]. Naproxen-induced PP and tanning-bed-induced PP most often affect women, but the latter may reflect social trends in gender use of artificial tanning. Among patients with end-stage renal disease, PP has been estimated to occur in 1.2–18% of those on hemodialysis and, less frequently, in those on peritoneal dialysis [1]. 2. Case Presentation A 67-year-old Caucasian female presented with several erythematous lesions of the lower limbs dating 6 months previously. She had a history of hand eczema, mild chronic renal failure of unknown aetiology, hypoparathyroidism, and hypercholesterolaemia. Her family history was unremarkable, except for her mother also suffering from eczema. She was under long-term treatment with amlodipine besylate, valsartan, nebivolol hydrochloride, paricalcitol, simvastatin, allopurinol, and metformin hydrochloride. On clinical examination, several slightly pruritic, roundish, sharply demarcated, erythematovesiculosus plaques were observed, symmetrically distributed over the anterior aspect of the lower legs and feet (Figures 1 and 2). Histological examination of lesional skin showed hyperkeratosis and acanthosis of the epidermis. In the papillary dermis, we