A lady presenting with segmental anhidrosis and heat intolerance.

Sir,

Anhidrosis can be the presenting symptom in a plethora of disorders, more common ones being leprosy, diabetic neuropathy, thyroid dysfunction, Sjögren syndrome, ectodermal dysplasia, autoimmune diseases, following anticholinergic medications etc., Herein we present the case of a middle-aged female who reported that the right side of her face was warmer than the left along with increased tendency for sweating.

A 35-year-old lady presented with the complaints of increased sweating on right side of her face and upper trunk since eight years with heat intolerance since last three years. Symptoms started 3-4 months after childbirth. The vaginal delivery was notable for prolonged labor and her receiving 4 units of whole blood for postpartum haemorrhage. She developed increased sweating over the right hemiface with notable absence of sweating on the left half of her face. Over time, the area with absent sweating progressed to involve other parts of body. At the time of presentation, she complained of absence of sweating over the left hemiface, left half of the upper trunk, and patchy areas on the abdomen and extremities; the remaining areas showed increased sweating. She complained of progressively increasing heat intolerance. She was unable to stay outdoors during daytime and complained of discomfort while cooking and during physical activity. Her increased sweating was severe enough to cause social embarrassment and hampered her quality of life. There were no other symptoms suggestive of systemic involvement. Mucocutaneous and systemic examination was noncontributory. However, eyes were notable for disparity in pupil sizes. On enquiry, we found that she had headache while reading and seeing near objects. Ophthalmic evaluation revealed anisocoria with left pupil larger than the right one. Left pupil was not reacting to light [Figures 1 and 2]. Besides, neurological examination revealed a reflexive ankle jerk and hyporeflexive knee-jerk on both sides. Neurological examination was otherwise noncontributory.

Figure 1

Photograph showing dilated pupil of the left side (Photograph taken by TOPCON TRC 50 DX retinal camera)

Figure 2

Photograph showing normal pupil of the right side (Photograph taken by TOPCON TRC 50 DX, retinal camera)

Autonomic testing revealed abnormal sudomotor responses manifested by patchy areas of anhidrosis affecting the face and trunk. This was documented by starch-iodine test [Figure 3a and b]. The diagnosis of Adie's tonic pupil was made, and it was confirmed by constriction response to (0.1%) diluted pilocarpine drops. Magnetic resonance imaging of the brain and cervical spine were noncontributory. Skin biopsy was performed from left and right cheek, and it did not reveal any significant difference. Sweat glands in the sample from left cheek too appeared normal in morphology and number. Considering the segmental anhidrosis (and hyperhidrosis), Adie's tonic pupil and absent deep tendon reflexes, a diagnosis of Ross syndrome (RS) was made. Patient was counseled about the limited therapeutic resources available for this condition and was offered botulinum toxin therapy for the hyperhidrotic areas, which she declined due to financial constraints.

Figure 3

Clinical photograph after starch iodine test showing increased sweating over the right hemiface (a) and absence of sweating over the left hemiface (b)

Ross syndrome (RS) is characterized by a triad of unilateral or bilateral segmental anhidrosis, hyporeflexia or areflexia and Adie's tonic pupils. It is not clear whether this condition is distinct from Holmes-Adie syndrome (tonic pupil and hyporeflexia) and Harlequin syndrome (segmental hypohidrosis without pupillary abnormalities).[1]

The exact etiopathogenesis is unknown. It could be due to an underlying apoptotic process involving the neurons derived from neural crest.[2] However, a few authors are of the opinion that microvascular ischemia mediated by an infectious agent or autoimmune process could be responsible.[3] Cytomegalovirus[4] and hepatitis C virus[5] have been documented in patients with RS. Interestingly, RS has also been described in a background of autoimmune thyroid disorder, Sjogren syndrome and antinuclear antibody positivity, suggesting an autoimmune etiology.[6] Disease process is known to be progressive and involvement of multiple segments has been documented.[1]

Ross syndrome appears to result from injury to sympathetic and parasympathetic ganglion cells or to their postganglionic projections. This explains tonic pupil and sweating disturbances; however, pathogenesis of diminished or absent deep tendon reflexes is unknown. Perretti et al. have shown impairment of mechanical pain perception in three patients of RS and believe that epidermal sensory fibers, both myelinated and unmyelinated too are involved, albeit late.[7]

The diagnosis is often clinical and is made by presence of characteristic triad. Demonstration of anhidrosis can be done by starch iodine test or infrared thermography.[8] Tonic pupil may be demonstrated by increased sensitivity and response to diluted pilocarpine (0.1%) eye drops.[9] Neurological examination can establish diminished or absent deep tendon reflexes.

There is no effective therapeutic management for Ross syndrome. Heat intolerance may be managed by wearing wet clothing during physical activity in order to prevent hyperthermia. Hyperhidrosis may be managed by iontophoresis and botulinum toxin injection. Recently, topical glycopyrrolate was found to be safe and effective in controlling hyperhidrosis.[10]