Descriptions of the clinical entity varicella, also known as chickenpox, and of zoster, also known as shingles, were found in the writings of the ancient Greek physicians. The name varicella is a word that is a diminutive form of the word for variola, which refers to the viral disease smallpox. We recognize today that the relationship between these two diseases is more literary than medical, ... [Show full abstract] although both viral agents produce vesicular eruptions that present as exanthema and these lesions are somewhat similar in appearance. That the lesions of smallpox are often larger and more numerous than those of varicella no doubt contributed to the mistaken notion that the latter disease was a diminutive form of the former. There is, however, no significant physical, chemical, or antigenic relationship between the viral agents that produce these two diseases. How varicella also became known as chickenpox is unclear. This popular name for this disease unfortunately also suggests a relationship to smallpox. By contrast, zoster is derived from a Greek word which means belt or girdle, an obvious reference to the localized type of infection associated with the intercostal clinical manifestations of this disease.