Aphthous stomatitis countries. Within nations, it is more common in higher socioeconomic groups. Males and females are affected in an equal ratio, and the peak age of onset between 10 and 19 years. About 80% of people with aphthous stomatitis first developed the condition before the age of 30. There have been reports of ethnic variation. For example, in the United States, aphthous stomatitis may be three times more common in white-skinned people than black-skinned people. "Aphthous affectations" and "aphthous ulcerations" of the mouth are mentioned several times in the treatise "Of the Epidemics" (part of the Hippocratic corpus, in the 4th
Philosophy of medicine populations in order to study their causes as well as how to manage, control, ameliorate the problems identified under study. Clinical medicine, as presented above, is part of a reductionist approach to disease, based ultimately on Cartesian dualism which says that the proper study of medicine is an investigation of the body when the latter is viewed as machine. A machine can exhaustively be broken down into its component parts and their respective functions; in the same way, the dominant approach to clinical research and treatment assumes the human body can be broken down/analysed in terms of its component parts