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
Anthroposophic medicine part it complements conventional medicine, and in part it substitutes for it. In 2008, Ernst wrote that it was being promoted as an "extension to conventional medicine". Ernst writes that Steiner used imagination and insight as a basis for his ideas, drawing mystical knowledge from the occult Akashic Records, a work which is supposedly situated on the astral plane, and which Steiner said was accessible to him via his intuitive powers. On this basis, Steiner proposed "associations between four postulated dimensions of the human body (physical body, etheric body, astral body, and ego), plants, minerals, and the cosmos". Steiner also