Paediatrics: Bulimia nervosa

Bulimia nervosa

Epidemiology

Bulimia nervosa is rare before the age of 13yrs. Although onset of the disorder is generally in mid- to late teens, it is unusual to present for help before early twenties. In teenagers, bulimia may occur alongside other externalizing teenage behaviours such as sexual promiscuity, drug taking drinking, and self-harming. 90% + of cases are female and is distributed right across the social classes. In adult women, the incidence is 1–1.5% and it is 2–3 times more common than anorexia nervosa in adolescents. Bulimia is associated with westernized lifestyle with a lower prevalence in developing countries and rural areas. There may, or may not be, a preced-ing history of anorexia nervosa.

Causes

Similar factors contribute to the aetiology of bulimia nervosa as are found for anorexia nervosa. Additional risk factors include:

·  adverse family life events;

·  family history of obesity;

·  parental substance misuse;

·  family history of affective disorder;

·  poor social network;

·  critical parents.

In contrast to anorexia nervosa, bulimia is associated with high expression of emotions, impulsivity, and a chaotic lifestyle.

Diagnostic features

·  Persistent preoccupation with eating. Craving for food with recurrent episodes of binge eating, associated with feeling out of control.

·  Regular use of mechanisms to reduce weight gain from binging (e.g. vomit-induction, laxatives, diuretics, appetite suppressants, excessive exercise).

·  Morbid fear of fatness.

·  Body weight higher than required for the diagnosis of anorexia.

Repeated vomiting and/or laxative abuse may result in serious electrolyte disturbance, seizures, tetany, haematemesis, or stomach rupture.

Management

Usually best managed by a multidisciplinary team and including the family from the start. Cognitive behavioural therapy including educational input about healthy eating, starvation, and binging. Motivational interviewing and family therapy can also be helpful. Pharmacotherapy, e.g. fluoxetine, rarely used, but may reduce food craving.

Prognosis

Full recovery occurs in up to 50% of cases. Between 66–75% show at least partial recovery at 10-yr follow up. Bone density follow up shows no oste-openia or osteoporosis in recovered bulimic patients.