The unilateral herpes zoster vesicles are typically confined to one or two dermatomes. This is a T4 distribution. The primary lesion is an umbilicated vesicle. Pain often precedes the eruption.

Herpes zoster vesicles turn cloudy; central umbilication evident. The grouped lesions are nearly confluent. The area may ultimately turn necrotic if there is underlying immunocompromise.

An obvious dermatomal distribution of vesicles on an erythematous base is classic of herpes zoster. The area may itch or be very painful or uncomfortable to even fine touch.