It started with his eyes. A 30-year-old man sought medical care after suddenly noticing that his pupils were different sizes. Doctors diagnosed an Adie tonic pupil, a pupil that responds sluggishly to light. Further examination found patches of skin that no longer sweated, other areas that sweated excessively to make up for them and missing tendon reflexes. Together, those findings pointed to Ross syndrome, a rare disorder of the nerves that run automatic body functions.
The unusual part came later. Over 15 years of follow-up, the side of his face that had been sweating too much turned pale and lost hair, in a pattern bounded by the midline of his face. Physicians affiliated with Universidad Anáhuac México reported the case online Aug. 3, 2026, in the Journal of Dermatology.
