E031 Scleromyxedema: a scleroderma mimic

Scleromyxedema is a rare chronic cutaneous mucinosis that can mimic scleroderma. It is typically associated with a monoclonal gammopathy, most commonly IgG-lambda, and can have a wide range of systemic manifestations. There should be an absence of thyroid pathology to exclude generalised or pretibial myxedema. Characteristic microscopic findings are mucin deposition, fibroblast proliferation and fibrosis.

A 55-year-old gentleman presented with 2 years of widespread skin thickening with prominent nodularity over his forehead, microstomia and evolving phimosis. He had a 1-year history of symmetrical inflammatory polyarthritis and reported some dysphagia with tablets with no other gastrointestinal symptoms. He had COPD with no recent change to his respiratory symptoms. Past medical history included hypertension, slightly low T3 and T4 with normal TSH.

On examination, he had significant total body skin thickening and sclerodactyly. He had a widespread papular eruption with sclerodermoid appearance and widespread waxy dome shaped papules on his face, trunk and extremities. The glabella was particularly involved with firm papules and deep furrows. He had a waxy brown eruption on abdomen and thickened, hard and tender nipples. He had no Raynaud’s phenomenon, telangiectasia, calcinosis, micro-ulceration or macroscopic nailfold capillary changes.

Ultrasound of hand and wrists showed symmetrical low grade inflammation of MCPs, wrists and dorsal wrist extensor compartments. He was found to have monoclonal IgG lambda paraprotein (3g/l). ANA, ENA, RF, CCP and anti-centromere antibodies were negative. He had borderline raised dsDNA antibodies (13 iu/ml) with negative Crithidia and normal complement, normal ESR and slightly raised CRP (10mg/L). His BNP was slightly raised (460ng/L) with a normal ECHO. Skin punch biopsies showed mucinous deposition within the dermis, histolytic infiltrate, fibroblastic proliferation and elastotic degeneration in the deeper dermis. He was diagnosed with scleromyxedema with possible extra-cutaneous organ involvement, given his arthritis and dysphagia.

He was treated with methotrexate 20mg once weekly with partial improvement in his arthralgia but not his skin changes. He was prescribed emollients and antihistamines by dermatology and subsequently referred to a tertiary centre for consideration of intravenous immunoglobulin (IVIG) treatment, other chemotherapeutic agents (such as cyclophosphamide, chlorambucil or thalidomide) and consideration of UVA1 for his skin.

This case demonstrates the typical association of an IgG-lambda monoclonal gammopathy with scleromyxedema. An unusual feature regarding the case was the relative paucity of fibrosis on skin biopsy. Usually in scleromyxedema, fibrosis is seen along with fibroblast proliferation and mucin deposition. The case highlights the need to consider possible scleroderma mimics- particularly in the absence of Raynaud’s and positive antibodies. An MDT approach should be adopted for complex multisystem cases with collaboration between specialties.

O. Collas: None. S. Ellis: Other; BSR Education committee.