BLISTERING SKIN IN A PATIENT ON PERITONEAL DIALYSIS
Miss Stephanie Lam1, A/Prof Rajesh Raj1
1Launceston General Hospital, Launceston, Australia
Background: Patients with advanced kidney disease can accumulate porphyrins due to poor excretion through urine or via dialysis. Iron overload can also generate an inhibitor of the uroporphyrinogen decarboxylase (UROD) enzyme. Together, these abnormalities may account for the association between kidney disease and porphyria cutanea tarda (PCT), characterised by painful, blistering, photosensitive skin lesions.
Case report: A 59-year-old woman established on peritoneal dialysis presented with painful blisters and superficial ulcers in her hands. Initially, an allergic reaction to skin cleansers was suspected, but she did not improve with appropriate changes. Serum ferritin was 858 µg/L, and rising, in the absence of any iron therapy or rise in other acute phase reactants. PCT was suspected, and further investigations confirmed this, including a urinary porphyrin/creatinine ratio of 1218nmol/mmol, elevated plasma porphyrins of 1081nmol/L and the presence of faecal isocoproporphyrin. Genetic analysis was normal. She initially received hydroxychloroquine and oral N-acetylcysteine, with advice to avoid sun exposure. Despite this, the skin lesions worsened, and serum ferritin levels rose to 2142µg/L. Iron chelation therapy with oral deferasirox 250mg daily was added. Following 2 months of therapy, response of skin lesions has been poor, although ferritin levels have declined to 1217µg/L.
Conclusion: Oral iron chelation therapy is a convenient and promising therapy, which has been partially successful in this peritoneal dialysis patient. Ferritin levels that do not respond to chelation may need to be treated with venesection, an option being considered in our patient. The painful and unsightly lesions of PCT demonstrate a rare aspect of the association between advanced kidney disease and skin changes. Unexplained elevation in iron stores and the characteristic skin lesions should prompt investigations.
Biography:
Stephanie is a first year nephrology advanced trainee at Launceston General Hospital in Tasmania.