Eponyms are names or phrases derived from or including the name of a person or place. These terms are used in a descriptive or adjectival sense1 in medical and scientific writing to describe entities such as diseases, syndromes, signs, tests, methods, and procedures. These eponymous terms should be distinguished from true possessives (eg, Homer’s Iliad). Medical eponyms are numerous (a website2 devoted to medical eponyms lists more than 7000), are frequently used in medical publications, and are treated in dictionaries of eponyms covering general medicine3 and some specialties, eg, neurology.4
Eponyms historically have indicated the name of the describer or presumptive discoverer of the disease (eg, Alzheimer disease) or sign (eg, Murphy sign), the name of a person or kindred found to have the disease described (eg, Christmas disease), or, when based on the name of a place (technically, toponyms), the geographic location in which the disease was found to occur (eg, Lyme disease). Traditionally, eponyms named after the describer or discoverer took the possessive form (-'s) and those named for other persons or for places took the nonpossessive form. As the use of the possessive form for all eponyms has become progressively less common (see 16.2, Nonpossessive Form), this formal distinction has faded.
Correct use of eponyms should be considered with a view toward clarity and consistency, the awareness that meanings can change over time and across cultures, and a desire to minimize misunderstanding in an increasingly global medical community.