Idiopathic segmental anhidrosis in an older patient presenting with recurrent dizziness

Dizziness is one of the most common complaints encountered in the outpatient clinic, which is difficult to diagnose, especially in older patients because of the multifactorial nature of the disease. Although not commonly recognised, anhidrosis can also cause dizziness.We report a case of a woman in her 70s who presented with long-term recurrent dizziness. She had a history of frequent hospitalisations for heatstroke. Physical examination revealed markedly less sweating in the left axilla and soles than in the right. Minol test revealed that most of the left side of her body, including the face, was anhidrotic. She was diagnosed with idiopathic segmental anhidrosis. We administered steroid pulse therapy without observing any significant effects.Although anhidrosis is a rare disorder, a careful interview and physical examination should be conducted to confirm a history of heatstroke and the absence of sweating to avoid missing the disease.