[Harlequin syndrome in a melanoderm patient]

INTRODUCTION

Harlequin's syndrome is a neurological disorder due to a dysfunction of the sympathetic innervation of the face. It has been rarely reported in the literature. The authors report one case occurring in a melanoderm patient.

OBSERVATION

A 38-year-old melanoderm man, without any history of surgery or neck trauma, consulted for a strictly right unilateral facial hyperhidrosis. Clinical and radiological investigations concluded to an idiopathic Harlequin's syndrome. Therapeutic abstention was proposed because of non-invalidating symptoms.

DISCUSSION

Harlequin's syndrome is a rare sudoral and vaso-motor disorder. On dark skin, flush and erythrosis may be subtle and the diagnosis less obvious. Etiologies are varied but essentially idiopathic. Its association with others dysautonomic facial syndromes is possible. Main differential diagnosis is the Frey's syndrome. Treatment is not clearly codified.

Idiopathic pure sudomotor failure: Anhidrosis due to deficits in cholinergic transmission

BACKGROUND

Acquired idiopathic generalized anhidrosis (AIGA) represents a heterogeneous clinical syndrome including sudomotor neuropathy and failure of the sweat glands. However, most AIGA cases comprise idiopathic pure sudomotor failure (IPSF), a distinct subgroup without sudomotor neuropathy or sweat gland failure.

METHODS

Eight patients with IPSF (mean +/- SD age 20 +/- 5 years) were assessed by thermoregulatory and pilocarpine-induced sweating tests, as well as emotional sweating using sudorometer (4 cases), microneurography of skin sympathetic nerve activity (2 cases), and skin biopsies from the forearm or axilla (3 cases).

RESULTS

Clinical features of IPSF comprise early onset; acute or sudden onset; concomitant sharp pain or cholinergic urticaria over the entire body; lack of autonomic dysfunction other than generalized anhidrosis; elevated serum IgE levels; and marked response to steroid. Sudomotor function testing revealed complete absence of thermoregulatory sweating, but well-preserved emotional sweating; pilocarpine did not induce sweating, and microneurography revealed that bursts of skin sympathetic nerve activity were not decreased; and skin biopsy displayed no morphologic abnormalities in sweat glands. The first two findings suggest lesions on the postsynaptic side of the nerve-sweat gland junction.

CONCLUSION

The lesions in IPSF may be in the muscarinic cholinergic receptors of sweat glands. Allergic mechanisms are probably involved in its pathophysiology.