- 1/3 of patients make a complete recovery
- 1/3 make only partial recovery and have many relapses
- And approximately 10-25% of patients will die. This can be from suicide, pneumonia or hypokaleamia (leading to arrhythmias).
Epidemiology and Aetiology
- Affects 1% of the population
- Most commonly affects girls (10:1)
- Incidence is rising in boys
- Typically affects intelligent, diligent and highly motivated individuals – they must be perfectionists to be able to have the willpower to avoid eating.
- Usually, patients come from happy families with little conflict – it is not an ‘attention seeking’ reaction to a ‘broken home’.
- Usually the girl will deny any weight loss, and disagree that she is too thin.
Phobia of normal body size and weight
Methods of reducing weight:
- Restricting calorie intake
- Use of laxatives
- Use of diuretics
Very low body weight
- There is a ‘critical weight’ (usually around 48Kg) below which amenorrhoea will occur. If the girl is not completely through puberty, she may regress to a pre-pubertal state
The control of weight may give the patients a sense of power – puberty can be a difficult time of maturity, when many patients feel they are ‘losing control’ of their local environment. Anorexia gives control over weight which may be comforting
Obsession and pre-occupation with food and cooking – many girls take up cooking as a hobby, although never eat any of their own food
- Low metabolic rate
- Cold peripheries
- Vitamin deficiencies & electrolyte disturbances
- Lanugo hair – fine downy hair that may appear on the body
- Skin changes
- Falsely low T3 level – giving appearance of hypothyroidism
- Low plasma proteins
- Ankle oedema
- ↓LH and ↓FSH
- Self Harm
- Treat the psychological disorder
- Encourage weight gain
- Alter behaviours that lead to the development of anorexia
- Only a small percentage of girls will continue to lose weight after admission. In these cases, tube feeding may be used.
- On admission, the patient is usually fed 2000 calories per day. This is not usually in big meals, as these can cause difficulties.
- Once a normal weight has been achieved, a more psychotherapeutic level of care is adopted. Signs that indicate a good prognosis include:
- Good relationship with the parents
- Ability to discuss previous suppressed emotional difficulties – usually around pressures of adolescence, growing up and relationships.
- More common than anorexia
- More common in girls
- Prevalence is increasing
- Typically affects older teenagers than anorexia
- Typically occurs 3-4 days after eating beings
- The result of a change in metabolism, from metabolising fats to metabolising carbohydrates
- Protein is a particular aetiological factor (e.g. in meat, milk and cheese)
- There are severe electrolyte disturbances, typically thymine and phosphate deficiencies, and there may also be hypoglycaemia, and low potassium and glucose.
- Lack of phosphate can lead to muscle weakness, which can result in diaphragmatic insufficiency.
- These deficiencies occur because there is a massive cellular uptake of electrolytes and thus serum levels fall.
Treatment and prevention
- Typically thiamine and vitamin B complex supplements are given when feeding resumes in anorexia.
- Biochemistry should be closely monitored, and any abnormalities in potassium, magnesium and phosphate should be corrected