Endocrine Abstracts

A 30-year-old female reported a 2-year history of excessive sweating / flushing affecting the right hand side of the face and scalp along with the right arm. These symptoms were generally related to exercise and demonstrated a sharp midline demarcation, being present only on the right hand side.

Past medical history included hypothyroidism secondary to Hashimoto’s Thyroiditis. She was euthyroid on levothyroxine. She also reported unequal pupils since age 12.

On examination, she was normotensive with no postural change in blood pressure. A tachycardia of 132 bpm was confirmed on ECG. She had tonic pupils, the right larger than left, with absent knee and ankle reflexes. No goitre or thyroid nodules were palpable.

Urine collections were negative for metanephrines and 5-HIAA. MRI cervical spine showed normal cervical spine with no surrounding mass lesions or thyroid abnormality.

A diagnosis of Ross’ syndrome, with left sided anhidrosis and compensatory hyperhidrosis on the right, was established.

Ross’ syndrome is the triad of tonic pupils, hyporeflexia and segmental anhidrosis with compensatory hyperhidrosis. This encompasses Holmes Adie syndrome – tonic pupils and hyporeflexia. The cause is unknown but is thought to result from generalised injury to peripheral autonomic and dorsal root ganglia. Prognosis is unclear and although generally benign, progression of cardiovascular autonomic dysfunction and widespread autonomic involvement is described in 28–40% of patients. Females are more commonly affected with average age on onset of 32. Presentation may be with orthostatic hypotension, due to afferent baroreceptor failure.

The diagnosis can be confirmed by autonomic testing and pupillography. No specific treatment is possible for the hyperhidrosis, but this may respond to cervical or thoracic sympathectomy.

Ross’ syndrome is distinct from Harlequin’s syndrome where a Horner’s complex is usually present and abnormalities of the inferior thyroid artery are often found.