Eating Disorders

Question 1

What is anorexia nervosa?

Answer 1

The most fatal of mental illnesses. There is a compulsive need to control eating and body shape. Weight loss becomes an overvalued idea.

Question 2

How are ‘ideal body shapes’ in anorexia achieved?

Answer 2

Food refusal (initially diet-restriction)
Over-exercising
Induced vomiting
Laxative abuse

Question 3

Can binge-eating be seen in anorexia nervosa?

Answer 3

Yes.

Theses are followed by remorse, vomiting and concealment

Question 4

What is the diagnostic criteria for anorexia nervosa?

Answer 4

1. Weight <85% predicted/BMI = 17.5
2. Intense fear of gaining weight/becoming fat with persistent behaviour that interferes with weight gain
3. Feeling fat when thin

Question 5

What is the epidemiology of anorexia nervosa?

Answer 5

More common in women by 4x

Typical onset mid-adolescence

Question 6

What are the risk factors for eating disorders?

Answer 6

Biological: genetics, serotonin dysregulation
Psychological: depression, anxiety, OCD, perfectionism, low self-esteem, absent sense of identity
Developmental: adverse life events, difficult relationships, dietary/feeding problems in early life, parents preoccupied with food
Socio-cultural: substance abuse, negative body images due to media exposure, image-aware activities (like ballet), teasing/criticism for fatness

Question 7

What are the physical signs of anorexia? (mainly due to starvation and vomiting)

Answer 7

General: fatigue, decreased cognition, altered sleep cycle, sensitivity to cold, dizziness
GI: constipation, fullness after eating
Reproductive: amenorrhoea, subfertility, psychosexual problems
Haematology: low WCC, anaemia, low platelets
Endocrine/metabolic: glucose abnormalities, low potassium, low phosphate, high bicarbonate, raised LFTs, raised amylase, raised T4, low TSH, low LH/O, high GH, high cortisol, high CCK, decreased renal function, osteoporosis
CVS: low BP, prolonged QT, arrhythmias
Neuro: reduced vision-spatial ability, reduced visual memory, peripheral neuropathy
Dental: caries
Derm: dry skin, brittle hair, lanugo hair

Question 8

What can be used to screen for eating disorders?

Answer 8

The SCOFF questionnaire

A score of over 2 indicates a likely eating disorder

Question 9

What are the differentials for eating disorders?

Answer 9

Depression
Crowns/coeliac disease
Hypothalamic tumours

Question 10

What are the red flags of eating disorders?

Answer 10

BMI<13
Weight loss > 1kg/wk
Temp <34.5
BP <80/50
Pulse <40
O2 <92%
Limbs blue and cold
Unable to get up without arms for leverage 
Skin purpura
Low potassium, sodium, phosphate
Long QT and flat T waves