|Abstract||This Guidance Note describes the identification of infection with those viruses that are capable|
of causing red rash as a major symptom of disease. Rashes may occur either as a direct
result of infection of the skin, or as a secondary phenomenon due to the host immune
response or an interaction between host immune response and virus in the skin. For the most
part the rashes that arise from viruses that replicate in the skin are typically vesicular
(poxviruses, herpes simplex, varicella-zoster), or nodular (papillomavirus) lesions.
Rashes may be morbilliform (erythematous macules and papules) or scarlatiniform (confluent
Viral rashes and drug reactions are usually morbilliform, while scarlatiniform rashes tend to be
seen in bacterial infections which produce exotoxins.