Because of the COVID19 pandemic, you are practicing telemedicine. You are shown a photograph of a 38-year-old woman taken after she completed her daily run of about one kilometer. She says she always looks this way after vigorous exercise, but normally her skin color is the same on both sides of her body. She is otherwise healthy and asymptomatic.
What is your diagnosis, what test(s) would you order to confirm your suspicions, and what treatment, if any, do you recommend?
DIAGNOSIS: Harlequin syndrome (HS) due to a thoracic sympathetic ganglion tumor (see radiograph arrow above).
A rare autonomic nervous system disorder, HS is characterized by hemifacial cutaneous sympathetic denervation with consequent anhydrosis and lack of facial rubor on the involved side. Occassionally patients present with a complete Horner's syndrome including myosis, ptosis, and enophthalmos on the affected side. Paradoxically, as in the presented case, there is compensatory flushing and sweating on the unaffected side. The syndrome becomes clinically evident in the setting of exercise, heat and emotional stress. Most cases are primary without demonstrable anatomical abnormalities, or, as in the presented case, may be associated with tumors involving cervical sympathetic ganglions. The syndrome may be congenital, follow sugical interruption of sympathetic pathways, or, rarely, occur in strokes involving the hypothalamus.The treatment in the presented case was surgical, but in most cases it is supportive