Scleroderma-like disease is defined as fibrosis of the skin caused by certain chemicals, drugs, environmental factors, or metabolic abnormalities, which manifests as scleroderma-like changes.1,2 However, large deposits of urate crystals in the skin and subcutaneous fascial tissue causing scleroderma-like disease have not been reported in the literature.
The patient was a 35-year-old male with a 7-year history of gout and a blood uric acid level over 1000 μmol/L. Tophus started to form in the metatarsophalangeal joints 3 years ago, and he had been confined to a wheelchair for the past year due to painful skin sclerosis and severe limitation of joint function in the lower extremities. Physical examination revealed sclerotic, tight, shiny, hard-to-twist skin on the bilateral forearms, bilateral buttocks, bilateral thighs, and bilateral calves, with atrophy and shrinkage of hair follicles (Figure 1). The sclerosis of the skin and the painful tendons resulted in limited movement of the extremities. We initially considered gout combined with systemic sclerosis as a possibility. Subsequent tests showed a negative antinuclear antibody profile, elevated blood uric acid concentration (776 μmol/L; normal range 208-428 μmol/L), and extensive calcium deposits on digital radiography of the extremities (Figure 2A). Urate crystals were seen in the lower leg biopsy tissue (Figure 2B). The final diagnosis was scleroderma-like disease due to diffuse monosodium urate crystal deposition. The patient was treated with febuxostat, and his symptoms were partially relieved after 1 year, as evidenced by his achievement of living out of a wheelchair.
Tight skin on both lower extremities; hard-to-twist appearance; tophus scattered around each joint.
(A) Heterogeneous increase in skin and soft tissue density around both knees. (B) Dichromatic urate crystalline-like material and necrotic material (H&E stain, 100×).
Footnotes
This work was supported by National Natural Science Foundation of China (No. 82205105). The authors declare no conflicts of interest relevant to this article. Ethics committee approval from “Commission cantonale d’éthique de la recherche, Genève” was not needed for this article type. Written informed consent was obtained from the patient.
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