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.