Evaluation of pustular rash

A pustular rash is defined as the occurrence of a rash that is composed of pustular lesions. A pustule is a vesicle or bulla containing purulent material. It varies in size and may occur at different levels within the epidermis: subcorneal, intraepidermal, or basement membrane zones.

When the pus is contained within the dermis, the lesion is called an abscess or furuncle. If it is deep and dissects through tissue planes it is called a carbuncle. The pustules may or may not be sterile and are normally filled with neutrophils.

This monograph covers purely pustular rashes as well as vesicular eruptions that develop into pustular rashes.