Scleromyxoedema is a rare chronic cutaneous mucinosis with generalised papular and sclerodermoid eruption, associated with monoclonal gammopathy (IgG lambda in 80%).

Adults aged 30 to 80; no thyroid disease (distinguishing from pretibial myxoedema).
Fibroblast proliferation and mucin (hyaluronic acid) deposition driven by circulating factors.
Systemic involvement: neurological (dermato-neuro syndrome: encephalopathy, seizures, coma), rheumatological (arthritis, myopathy), pulmonary (restrictive disease), cardiac, renal, gastrointestinal (dysphagia), Raynaud.
Progression to myeloma is uncommon (about 10%).

Diagnostic criteria: generalised papular and sclerodermoid eruption, monoclonal gammopathy, mucin deposition with fibroblast proliferation and fibrosis, absence of thyroid disease.
Skin biopsy: dermal mucin (Alcian blue positive), fibroblast proliferation, collagen deposition.
Serum and urine protein electrophoresis with immunofixation, free light chains; marrow biopsy to exclude myeloma.
Thyroid function; exclude nephrogenic systemic fibrosis, systemic sclerosis, scleredema, lichen myxoedematosus.
Neurological work up (MRI, EEG) if symptoms; pulmonary function tests, swallow study, CK.

First line: IVIG 2 g/kg per cycle (given over 2 to 5 days) monthly, with excellent response in most (skin softening and systemic improvement); maintenance by extending intervals.
Second line: thalidomide 50 to 200 mg daily, lenalidomide 10 to 25 mg daily, bortezomib 1.3 mg/m2 with dexamethasone for refractory disease or myeloma.
Systemic corticosteroids (prednisolone 40 to 60 mg) in dermato-neuro syndrome, combined with IVIG, plasmapheresis.
Autologous stem cell transplantation for refractory severe disease, melphalan.
Skin directed: phototherapy (PUVA), extracorporeal photopheresis, topical steroids.
Monitor for myeloma yearly (protein electrophoresis, free light chains).

Scleromyxedema

Overview

Clinical Features

Diagnosis

Management