Segmental Pallor and Hair Loss in a Patient With Ross Syndrome: Case Report.

A 30-year-old male sought medical consultation due to sudden anisocoria. Clinical examination confirmed Adie's tonic pupil. Subsequently, the presence of segmental anhidrosis with compensatory hyperhidrosis and areflexia established the diagnosis of Ross syndrome. In a 15-year follow-up, uncommon manifestations developed in the facial territory affected by compensatory hyperhidrosis: unilateral facial pallor and alopecia following a midline-defined pattern. This case emphasizes the importance of recognizing neurocutaneous manifestations in dermatology practice and suggests that Ross syndrome may encompass a broader spectrum of dermatological findings than currently recognized.