Herpes zoster in the T1 dermatome presenting with Horner's syndrome, radicular weakness, and postherpetic neuralgia.

Herpes zoster is caused by varicella zoster virus infection involving the dorsal root ganglia of spinal nerve roots. This common problem can be associated with multiple neurological abnormalities. We present a case of Herpes zoster affecting the T1 dermatome associated with ipsilateral Horner's syndrome and radicular weakness.