A gangrenous ulcer due to a growth of bacteria in the tissues of the mouth. The majority of cases begin with simple ulcers of the gums which, if untreated with antiseptics or antibiotics, can progress towards noma proper through transmission to the soft tissues of the mouth and face in contact with the periodontal lesions. This involves extensive painful swelling, then full-scale establishment of the the gangrenous process and, when the outer scab falls off, a gaping hole in the face. If the victim does not receive hospital treatment, 80 percent die during these later stages, mostly from septicaemia. The survivors suffer the twofold affliction of disfigurement and functional handicap. The scar tissue restricts jaw movement; the loss of tissue may also include facial bones. Repair is lengthy, difficult and very expensive, so most survivors live with the sequelae and never again are able to speak or eat normally.
The disease occurs almost exclusively in weakly children suffering from chronic malnutrition and/or following severe infectious or parasitic disease, most commonly measles but also scarlet fever, chicken pox and, occasionally, a malaria attack. Poor dental hygiene and the presence of gingivitis are predisposing factors. The nutritional deficiencies most frequently observed to be related are vitamin and protein deficiencies and iron deficiency anaemia. The weaning period is regarded as extremely critical.
According to WHO, every year several hundred thousand children in developing countries under the age of six fall prey to noma. Peak incidence is between 3 and 4 years of age. African countries lead, and incidence there seems to be increasing. Latin America and Asia also report a significant number of cases.