Segmental anhidrosis and heat intolerance

Abstract

A 62 year-old woman with no previous medical history presented to the Dermatology department with sweating disorders for several years. She described segmental hyperhidrosis and hyperemia while running. This excessive sweating occurred in the left hemiface, the left half of the trunk, the left upper limb and the right lower limb (Fig. 1A). This was associated with heat intolerance and previous faintness during sport. She did not describe any chest pain before faintness and the cardiac auscultation was normal. The neurological examination revealed a diffuse areflexia in the absence of any sensory or motor disorders. By illuminating the right eye, we observed a delay in ipsilateral pupillary contraction, whereas we observed an absence of the consensual photomotor reflex of the right eye by illuminating the left eye (Adie's tonic pupil, Fig. 1B and C, and Supplementary file 1). However, she did not complain of reduced visual acuity. Ross syndrome is a rare autonomic disorder caused by a selective degenerative process of the postganglionic cholinergic sudomotor neurons [[1]Sommer C. Lindenlaub T. Zillikens D. Toyka K.V. Naumann M. Selective loss of cholinergic sudomotor fibers causes anhidrosis in Ross syndrome.Ann Neurol. 2002; 52: 247-250Google Scholar]. Ross syndrome is diagnosed by the presence of a triad of symptoms associating segmental anhidrosis (with compensatory hyperhidrosis), Adie's tonic pupil and areflexia [[2]Mishra A.K. Kharkongor M. Kuriakose C.K. George A.A. Peter D. Carey R.A.B. et al.Is ross syndrome an autoimmune entity? A case series of 11 patients.Can J Neurol Sci. 2017; 44: 318-321Google Scholar]. The main complaint of patients is generally the segmental compensatory hyperhidrosis, the anhidrosis in contrast is not even noticed. The two other signs must be specifically examined for to make the diagnosis. The deep tendon hyporeflexia or areflexia affects the four limbs, whereas the tonic pupil is observed on the pathological and anhidrotic side of the face. It has been proposed to treat hyperhidrosis with botulinum toxin [[3]Bergmann I. Dauphin M. Naumann M. Flachenecker P. Müllges W. Koltzenburg M. et al.Selective degeneration of sudomotor fibers in Ross syndrome and successful treatment of compensatory hyperhidrosis with botulinum toxin.Muscle Nerve. 1998; 21: 1790-1793Google Scholar], but this treatment may theoretically increase the heat intolerance and the risk of faintness during sport. Even if the disorder is benign, the objective is to avoid any faintness. Clinicians should advise patients with Ross syndrome to wear light clothing for sports and to avoid excessive heat exposure.