Teaching Case

Skin rash and muscle weakness

Skin rash Scaly lesions on dorsum of hands Muscle weakness - especially affecting proximal muscle groups Generalised muscle ache - tender on examination On long-term, intermittent steroid therapy

This is an inflammatory polymyopathy of striated muscle accompanied by dermatological features. Characteristic soft tissue abnormalities are oedema followed by atrophy. In the healing phase there may be extensive soft tissue calcification in subcutaneous and intermuscular planes resulting in severe flexion contractures in the later stages. Osteopaenia may be a prominent feature of the condition compounded by the effect of steroid therapy, and the latter may be complicated by avascular necrosis. Secondary infection may also complicate steroid therapy as a result of immune-suppression. Opportunistic lung infections may be one such manifestation. Diffuse, multiple or generalised soft tissue calcification may be seen in:- hyperparathyroidism and renal osteodystrophy other disorders of calcium and phosphate metabolism eg. hypoparathyroidism, chronic haemodialysis, milk-alkali syndrome, etc. scleroderma dermatomyositis polyarteritis nodosa Raynaud’s syndrome rheumatoid arthritis systemic lupus erythematosus sarcoidosis gout ochronosis Ehler’s-Danlos syndrome Werner’s syndrome (adult progeria)