Unusual painful sclerotic plaques on the legs of a patient with late diagnosis of primary hyperoxaluria type I

Sir, we report the case of a 49‐year‐old woman who presented with firm dermal plaques which were symmetrically located on the lateral sides of the thighs (Fig. 1A) and almost covered the whole circumference of both lower legs. On the thighs, a discrete reticular livedo was visible and the skin above the plaques appeared ‘peau d'orange‐like’ (Fig. 1A). On the lower legs, the skin was hyperpigmented and superficial white miliary, warty papules were apparent on the anterior and lateral sides (Fig. 1B). The indurations had been present for 2 years, progressed over the last few months and became increasingly painful. The patient history revealed recurrent urolithiasis since age 19 years, which lead to end stage renal failure at age 28 years. Without further diagnostic evaluation the patient twice received isolated kidney transplants (in 1991 and 1998) that subsequently ‘calcified’ and lost their function. Two years later, severe visual impairment developed and, following a retinal examination showing multiple calcium–oxalate (CaOx) crystal deposition in the inner retina, the diagnosis of primary hyperoxaluria type I was suspected and subsequently confirmed by liver biopsy. Alanine : glyoxylate aminotransferase activity was reduced (6·2 µmol h−1 mg−1 protein, normal 19·1–47·9) and the patient was found to be compound heterozygous for the G630A (new nomenclature G508A) and the T576A (T454A) mutations, both being associated with peroxisomal to mitochondrial mistargeting of the enzyme. A successful combined liver/kidney transplantation was performed in November 2002.