We read the article by Lewis and Holt1 with great interest. They described a patient with segmental hyperhidrosis, hyporeflexia, and tonic pupil. We agree with the diagnosis of Ross syndrome.
We would like to point out that segmental hyperhidrosis can also be secondary to herpes zoster.2 Chopra et al2 reported the case of a 31-year old, human immunodeficiency viruspositive man who developed herpes zoster in his left arm in the distribution of the left eighth cervical nerve 7 days before presentation. The herpes zoster resolved after 6 weeks. Two weeks later, he developed segmental hyperhidrosis evoked with heat stimuli in the same site as that of the herpes zoster. This isotopic response3 (the occurrence of a new disorder at the same site of an unrelated and healed skin condition) most commonly occurs when the original condition was herpes zoster.3 At the 6-month follow-up, the segmental hyperhidrosis had resolved.
Wu JJ, Murase JE, Huang DB, Tyring SK. A Unique Pattern of Hyperhidrosis and Herpes Zoster. Arch Dermatol. 2006;142(8):1065-1086. doi:10.1001/archderm.142.8.1069-a