To collect nationally representative epidemiological data on early-onset eating disorders (EOEDs) in children.

Prospective, active surveillance using the Australian Paediatric Surveillance Unit with key informant design.

Child health specialists in Australia (July 2002 to June 2005).

Incident cases of EOEDs in children aged 5–13 years.

Disease rates, demographic characteristics, clinical features and complications, hospitalisation, psychological comorbidity, and concordance of clinical features with Diagnostic and statistical manual of mental disorders, fourth edition (DSM-IV) criteria.

We identified 101 children aged 5–13 years with EOEDs (median age, 12.2 years; range, 5.5–13.9 years), of whom one in four were boys. Most were hospitalised (78%), and the mean duration of hospitalisation was 24.7 days (range, 1–75 days). More than 70% of inpatients were admitted to specialised eating disorder units in paediatric teaching hospitals. Among inpatients, 37% met DSM-IV diagnostic criteria for anorexia nervosa; although 61% had life-threatening complications of malnutrition, only 51% met weight criteria. Psychological symptoms were similar to those in adults with anorexia nervosa: 67% of inpatients met both psychological diagnostic criteria for anorexia nervosa (fear of weight gain/fatness and misperception of body shape). Of 19 postmenarchal girls, 18 had secondary amenorrhoea. Nasogastric feeding was used in 58% of inpatients, and 34% received psychotropic medications.

This is the first prospective national study of EOEDs. It demonstrates the limitations of applying DSM-IV diagnostic criteria for anorexia nervosa to young children; the high proportion of boys affected by EOEDs; and the significant psychological comorbidity and high frequency of hospitalisation associated with EOEDs. Potentially life-threatening medical complications are common at presentation, suggesting possible missed diagnoses and a need for education of health professionals. The study underlines the severity of EOEDs and the need for joint medical and psychiatric specialist management.