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
History of medicine in the Philippines Rodrigo de San Miguel's "Manual de Medicina Domestica" (Manual on Domestic Medicine), and Fr. Manuel Vilches' "Manuel del Mediquillo Visaya" (Manuel of the Visayan Traditional Healers). Philippine National Artist and painter Carlos "Botong" V. Francisco recorded and depicted the history of medicine in the Philippines by creating four mural-like four-panel oil paintings collectively titled "The Progress of Medicine in the Philippines", which traced the practice of medicine from the times of the "babaylans" ("medicine men and women") up to a period in the modern-day era. The first painting depicts pre-colonial medicine, the second portrays medicine during the Spanish colonial period,