Nephrogenic fibrosing dermopathy: response to high-dose intravenous immunoglobulin

Sir, Scleromyxoedema‐like cutaneous disease, also called nephrogenic fibrosing dermopathy (NFD), is a new entity described recently. Patients with NFD had undergone haemodialysis, peritoneal dialysis or renal transplant and showed hardened and thickened skin lesions of acute onset localized chiefly to the extremities with resulting flexion contracture of the joints in some cases. Although some of the clinical and histological manifestations of NFD are similar to scleromyxoedema, monoclonal paraproteinaemia and facial involvement were not observed in any patient and there was no evidence of systemic organ involvement.1–6 Because the pathogenesis is unknown and there are no controlled studies of the treatment of NFD, treatment trials have been largely empirical. We report a patient with NFD treated with high‐dose intravenous immunoglobulin (hdIVIg) based on the histopathological similarity between NFD and scleromyxoedema. A 61‐year‐old man was referred with a 4‐month history of skin thickening on both arms and legs and right inguinal area. Clinical examination revealed multiple, hyperpigmented and indurated plaques with a ‘peau d’orange' appearance on the surface (Fig. 1A). He showed flexion contracture of the fingers, wrists and elbows on both sides, without pain. He had been on peritoneal dialysis for 8 months, necessitated by an end‐stage renal disease secondary to renal damage triggered by radiocontrast agents. Tests for antinuclear antibody, antidouble‐stranded DNA, antiphospholipid antibody and rheumatoid factor were negative. Serum immunoelectrofixation testing was negative for paraprotein. A 3‐mm punch biopsy taken from a hardened plaque on the right forearm revealed haphazardly arranged dermal fibroblasts associated with thick collagen bundles separated by prominent clefts (Fig. 1B). Alcian blue staining confirmed the presence of interstitial mucin deposition (Fig. 1C) and Verhoeff–van Gieson staining revealed an increased number of thick and thin elastic fibres orientated parallel to the epidermis (Fig. 1D). The CD34+ dendritic network was closely apposed to elastic fibres, and CD68+ mononucleated and multinucleated cells were seen. Based on the above clinical and histological features we diagnosed this condition as NFD. Our patient was treated with hdIVIg 0·4 g kg−1 daily for 5 days each month. For a period of 3 months, the response to treatment was assessed by measuring the range of motion of affected joints. The first cycle was well tolerated and he felt symptomatically better, which correlated well with the improvement of the range of motion measured 1 month later. The ranges of motion of the wrists and hands were improved more than those at other areas. Physical examination revealed that the skin became more lax but he did not show further improvement after the second and third cycles of hdIVIg (Table 1).