A 69-year-old man with excessive sweating of the right hemithorax.

The pure autonomic failure is a rare entity, with only a few cases reported in the literature. The authors describe a case with compensatory excessive sweating of the right hemithorax as an initial manifestation of a pure autonomic failure, and the authors review the clinical characteristics of this disease. A 69-year-old man presented excessive sweating of the right hemithorax. Physical examination revealed orthostatic hypotension. No other neurological features were present. The autonomic study showed a low heart rate response to the Valsalva maneuver and reduced supine plasma norepinephrine levels. A pure autonomic failure was diagnosed. Treatment did not improve patient's symptoms. Anhidrosis with asymmetrical compensatory hyperhidrosis can be the only symptom of a pure autonomic failure. The authors highlight an unusual form of presentation of a rare disease, difficult to diagnose if it is not taken into consideration.