Erythromelalgia presenting with body pain.

A 69-year-old woman presented to the general outpatient clinic with a 2-month history of erythema and burning sensation across her neck, bilaterally in her upper limbs and thighs and on her palms and soles, where it was especially severe. The pain was aggravated by hot baths and exertion, and relieved by cooling. She had no notable medical or family history and took no medications.

On examination, the patient had erythema and swelling on both palms (Figure 1), which she reported as painful. Her full blood count, antinuclear antibody, HIV antibody, rheumatoid factor and nerve conduction studies were normal. We diagnosed idiopathic primary erythromelalgia and prescribed misoprostol 400 mg daily. Two weeks later, she had partial resolution of pain, erythema and swelling, and at 1 year, she remained in partial resolution, without relapse, on misoprostol.

Figure 1:

Photographs of the hands of a 69-year-old woman with erythromelalgia showing bilateral palmar erythema and swelling, which the patient reported as painful.

Erythromelalgia is characterized by burning pain, erythema and paroxysmal hyperthermia, primarily affecting the extremities but infrequently extending to the neck, face, ears, nose, thigh and vulva.1,2 It is exacerbated by exercise and hot environments, and relieved with cooling (the opposite of Raynaud phenomenon). Incidence is 0.36–1.3 cases per 100 000 population per year; it is more common in women and smokers.1

Differential diagnoses include polyneuropathy, acrocyanosis, peripheral arterial disease, Raynaud phenomenon, cellulitis, gout, Fabry disease and vasculitis.3 Primary erythromelalgia is idiopathic or inherited with a genetic association with gain-of-function mutations in SCN9A; our patient declined genetic testing. Secondary erythromelalgia results from an underlying medical disorder, including myeloproliferative diseases, vascular disorders, connective tissue diseases and some medications.1,3

No single therapy is effective, although vascular agents, sodium-channel blockers, anticonvulsants, antihistamines and immunosuppressants have been used.3 Patients usually require a timed trial of, often multimodal, pharmacotherapy.3 Misoprostol, a prostaglandin E1 analog that decreases arteriovenous shunt flow and increases capillary circulation, was helpful for our patient.3

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