pseudoporphyria ( pp ) is a rare , photodistributed bullous dermatosis that clinically , histopathologically , and immunologically resembles porphyria cutanea tarda ( pct ) but 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 . " subsequently , pp has been associated with numerous photosensitizing medications , hormone replacement , and ultraviolet a ( uva ) radiation in tanning beds , hepatitis c , sarcoidosis , sjogren syndrome , hepatoma , hiv infection and lupus erythematosus . drugs commonly associated with pseudoporphyria are naproxen , tetracycline , fluoroquinolones , voriconazole , furosemide , chlorthalidone , butamide , hydrochlorothiazide / triamterene , amiodarone , cyclosporine . a 49-year - old hypertensive male presented with swelling over the body for the last 1-month . on detailed clinical and diagnostic workup , he was diagnosed as a case of chronic kidney disease ( ckd ) stage 3 ( estimated glomerular filtration rate 51.6 ml / min/1.73 m ) of unknown etiology . he was prescribed torsemide , cilnidipine , calcium acetate , ferrous ascorbate , paricalcitol along with low salt and protein restricted diet . three weeks later he came with complains of several erythematous lesions of the forearm and around the wrist . on clinical examination , several slightly pruritic , round , sharply demarcated , erythematous vesicular plaques were observed , symmetrically distributed over the anterior aspect of the forearm . no evidence of hypertrichosis , hyperpigmentation or sclerodermoid changes was seen [ figure 1 ] . erythematous vesicular plaques on anterior aspect of the forearm and palm dermatological opinion was suggestive of a blistering disorder either porphyria cutaneous tarda or pp . histological examination undertaken of skin lesion showed hyperkeratosis and acanthosis of the epidermis . in the papillary dermis , we noted subepidermal cleft with preservation of papillae and no inflammatory infiltrate along with periodic acid stain positive , diastase negative , eosinophilic , donut - like rings around the capillaries as shown in figures 2 and 3 . direct immunofluorescence showed microgranular deposition of the c3 around the papillary dermal vessels as shown in figure 4 . levels of plasma porphyrins were normal ( protoporphyrin < 0.5 g / l ( normal < 0.75 g / l ) , coproporphyrin < 0.01 g / l ( normal < 0.01 g / l ) ; urinary levels were normal : porphobilinogen 6 mol / dl ( normal < 8 mol / dl ) , uroporphyrin 21 nmol / dl ( normal < 28 nmol / dl ) ; coproporphyrin i was normal at 12 nmol / dl ( normal < 35 nmol / dl ) ; and coproporphyrin iii was normal at 11 nmol / dl ( normal < 110 nmol / dl ) . nmol / g ) , and fecal total porphyrin was 10 nmol / g ( normal 050 nmol / g ) . other laboratory investigations were as follows : hemoglobin 9.6 g / dl ( normal range 11.514.5 g / dl ) ; serum iron 23 mol / l ( normal range 1030 mol / l ) ; ferritin 207 g / l ( normal range 50250 g / l ) ; alkaline phosphatase 102 u / l ( normal range 40120 u / l ) ; alanine aminotransferase 15 u / l ( normal range 1055 u / l ) ; and aspartate aminotransferase 19 u / l ( normal range 1040 u / l ) . screening for hepatitis viruses and the human immunodeficiency virus were negative . based on clinical and histological grounds , a diagnosis of pp was made torsemide was withdrawn , and the patient was treated for 4 weeks with antihistaminic with an only minimal improvement , which were then withdrawn . on 2 month follow - up , there was a significant improvement while in 4 months the lesions cleared completely with only residual post - inflammatory hyperpigmentation . skin biopsy with hematoxylin and eosin stain showing subepidermal cleft with preservation of papillae with no inflammatory infiltrate ( 40 ) skin biopsy with periodic acid schiff ( pas ) stain showing pas - positive diastase negative hyaline material thickening the wall of dermal vessel and dermo - epidermal junction ( 40 ) direct immunofluorescence - c3 deposits around dermal vessels and dermo - epidermal junction in 1964 , zelickson was first to describe this type of phototoxic reaction in patients after the use of nalidixic acid . in a retrospective study of 20 cases , the mean age at diagnosis was 50 years . among patients with the end - stage renal disease , pp has been estimated to occur in 1.218% of those on hemodialysis and , less frequently , in those on peritoneal dialysis . clinically , pp is characterized by bullae , developing on the photo - exposed skin , most commonly on the dorsum of the hands and feet , forearms , face , and neck . in contrast to pct , hypertrichosis , hyperpigmentation , and sclerodermoid plaques only rarely occur . of critical importance for the diagnosis of pp is the exclusion of true porphyria , especially pct . by definition , in pp porphyrin profile individuals with ckd tend to have higher serum porphyrin levels than normal , with some levels determined to be within the lower end of the range commonly found in pct patients with normal renal function . furthermore , plasma uroporphyrin levels are generally higher in patients on hemodialysis compared with those on peritoneal dialysis , which may explain the lower incidence of pp in the latter group . if the diagnosis of pp is suspected , biopsies for histologic evaluation with hematoxylin and eosin stains and direct immunofluorescence should be performed . serum samples may also be obtained for indirect immunofluorescence evaluation to aid in the exclusion of bullous pemphigoid . the histologic features of pp are similar to those of pct with subepidermal bullae and festooning of the dermal papillae and granular deposits of immunoglobulins , mostly igg , and c3 at the basement membrane zone and in the perivascular region . although direct immunofluorescence is not a useful tool in distinguishing pp from pct , it is helpful in the evaluation of other entities in the differential diagnosis of pp , specifically epidermolysis bullosa acquisita . epidermolysis bullosa acquisita can be ruled out by the lack of intense , linear immunoreactants at the dermal - epidermal junction . the thickness of the blood vessel wall may prove helpful in differentiating pp from pct . in a comparative histologic study from biopsy samples of patients with pct and pp , maynard and peters found thickened blood vessel walls in 11 of 13 patients with pct . in contrast , similar findings in only 1 of 9 patients with pp were present . formation of phototoxic metabolites in genetically predisposed individuals may trigger the development of bullous lesions . in general , the action spectrum has been assumed to be in the range of uv radiation or possibly , visible light . these patients are at high - risk of oxidative stress due to deficiency of glutathione in the blood and erythrocytes , which may increase their susceptibility to the effects of uv exposure at even lower porphyrin levels . in addition , clearance of plasma - bound porphyrin precursors may lead to excessive porphyrin deposition in the skin . it could also be related to aluminum hydroxide , which is found in the dialysis solution and has been shown to produce a porphyria - like reaction to rats . in cases of drug - induced pp , withdrawal of the suspected photosensitizing medication results in improvement usually within weeks to months ( average 8 weeks ) which were seen in our case . strict uv rays protection , including a broad spectrum sunscreen , is crucial . in hemodialysis - associated pp , there are reports of complete resolution after treatment with n - acetylcysteine ( 8001200 mg p.o . daily for 8 weeks ) , a glutathione precursor , but some authors noticed recurrence when the drug was discontinued . our patient is probably the second reported case , of pp developing in dialysis naive ckd patient , first from india . the question whether it is the disease ckd or the management ( hemodialysis ) which contributes most to the occurrence of pp remains to be answered . dialysis in genetically predisposed patients may indeed contribute to pp development , either by the resulting in oxidative stress or by reflecting a more advanced stage of renal failure . finally , but a thorough drug history should be ascertained in such cases , which might minimize the morbidity associated with this disorder .
pseudoporphyria ( pp ) is used to describe a photodistributed bullous disorder with clinical and histologic features of porphyria cutanea tarda ( pct ) but without accompanying biochemical porphyrin abnormalities . 
 medications , excessive sun and ultraviolet radiation exposure , have all been reported to develop pp . 
 we report a case of pp in a 49-year - old man with ckd stage 3a , caused due to torsemide intake . 
 this is probably the first reported case of pp developing in a dialysis naive patient ckd due to torsemide intake from india .