Herpes zoster is a painful, blistering rash that typically manifests in a dermatomal distribution and is caused by reactivation of varicella-zoster virus infection. A classic presentation of herpes zoster involving the right T4 dermatome is illustrated in Figure 1. The patient was a 90-year-old man who experienced severe pain on the right side of his neck and chest followed by development of maculopapular lesions. The lesions, which ranged from macular to vesicular, resolved with no scarring or postherpetic neuralgia following 10 days of therapy with oral acyclovir and intramuscular injections of γ-globulin.
Figure 1 – These images illustrate a classic rash indicative of herpes zoster.
The location of the macular and vesicular lesions suggests involvement of the T4 dermatome. (Images and case supplied by William A. Hayes, MD.)
Figure 2 also depicts herpes zoster involving the T4 dermatome, but the T10 dermatome is involved as well. Typically, a single dermatome is affected; involvement of 2 distinct dermatomes is rare. This case occurred in a 66-year-old man who had been hospitalized because of left-sided chest pain. Cardiac evaluation revealed no abnormalities. The patient was discharged; however, that evening, painful, vesicular lesions on erythematous bases simultaneously began to develop along the left T4 and T10 dermatomes. The pain and rash resolved within a week of management with acyclovir at a dosage of 800 mg qid.
Another unusual case of herpes zoster is depicted in Figure 3. When vesicles developed on the right sole of a 35-year-old man, he thought he was having a recurrence of athlete's foot. The pain and tenderness in the area suggested herpes zoster. Note that the vesicles and erosions correspond to the S1 dermatome.