Cervical dermatomal zona misdiagnosed as ulnar nerve entrapment.

Herpes zoster is a secondary reactivation of primary contagious varicella-zoster virus in the dorsal root ganglia. While thoracic zona is common, cervical dermatomal zona is a rare segmental complication of herpes zoster and can be easily misdiagnosed as other diseases. This article describes a patient with initial neuralgia without dermatomal lesions that was treated as ulnar nerve entrapment syndrome until manifestation of herpetiform cutaneous lesions appeared. It is important that clinicians should be aware of the possibility of zoster infection when evaluating the onset of neuralgia in a dermatomal distribution in the upper limb, especially without rash.