Isaacs syndrome associated with polyarteritis nodosa.

Isaacs syndrome (IS) is a rare peripheral nerve hyperexcitability disorder, often associated with an underlying disease. We report a clinical case which appears to be a previously unreported co-occurrence of IS and systemic polyarteritis nodosa, diagnosed in a young woman presenting with subacute back pain, weight loss, fasciculations, diaphoresis, tachycardia, micturition disorder, constipation, cutaneous lesions and mesenteric vasculitis on MRI. The patient achieved clinical remission following treatment with intravenous cyclophosphamide and corticosteroids.