Eating disorders Flashcards
ICD-10 diagnostic criteria for anorexia nervosa
- Low weight: BMI<17.5 (weight loss or lack of weight gain in children, <5thcentile)
- Weight loss is self-induced by avoidance of “fattening foods”
- Self-perception of being “too fat” leading to low weight threshold, even when thin
- Irrational fear of fatness
- Amennorhoea
Definition of atypical anorexia nervosa
Fulfills some but not all features of AN (e.g. may have weight loss behaviours in absence of endocrine changes/dread of being fat)
ICD-10 criteria for bulimia nervosa
- Recurrent episodes of overeating: 1000-4000 kcal, loss of control
- Compensatory behaviours e.g. purging, starvation, exercise, drugs
- Preoccupation with eating
- Perception of being too fat/dread of fatness
Time criterion for bulimia nervosa
>=2 episodes of overeating per week, for 3 months
Criteria for binge-eating disorder (DSM-V)
- Recurrent episodes of binge-eating: characterised by lack of control
- Distress: regarding binge-eating (depression frequently co-morbid)
- No compensatory behaviour: BMI >25
Time criteria for binge-eating disorder
>=1 per week for 3 months
Features of binge eating episodes in binge-eating disorder
>=3 of:
- Eating until uncomfortably full
- Eating when not physically hungry
- Eating alone due to shame/embarrasment
- Eating more rapidly than normal
- Feelings of disgust, guilt, depression afterwards
Biological predisposing factors for eating disorder
- Female
- Genetics (56% AN, up to 80% BN)
- Early menarche (BN)
- Obesity (BN)
- +ve FHx (?biological)
Psychological predisposing factors for ED
- Perfectionism (AN)
- Low self-esteem
- Sexual abuse (less common in ED, little evidence)
- Anxiety
- Impulsivity (BN)
- FHx of obesity (BN)
- PPH of eating disorder (AN –> BN)
Social predisposing factors for ED
- Adverse parenting (arguments, expectations, contact)
- Western society
- Specific groups (e.g. models)
Biological precipitating factors for ED
- Dieting/lent
- Illness/infection
- Puberty
Psychological precipitating factors for ED
- Emotional stress
- Bullying/critical comments
Social precipitating factors for ED
- Family dieting
- Peer group/lifecycle transition
Biological perpetuating factors for ED
Neuroendocrine dysregulation
e.g. 5-HT disturbance makes psychopathology worse
Psychological perpetuating factors for ED
- Over-valued intrusive ideas re: weight
- Abnormal weight perception
- Co-morbid mood disorder (esp depression)
Social perpetuating factors for ED
+ve reinforcement from friends/family
Average age of onset for EDs
AN: 15-16 years old
BN:20
BED: 23
F:M prevalence ratio for eating disorders
6:1 in community, 10:1 in clinical samples
Prevalence of ED
AN: 1%
BN: 1%
BED: 1-2%
Physical symptoms in anorexia nervosa
- Sensitivity to cold
- Amennorhoea/delayed onset of puberty
- Reduced sex drive
- Dizziness, fatigue
- Poor concentration
- Poor sleep
- GI symptoms: constipation, bloating
Physical signs of anorexia nervosa
- Cold extremities
- Sarcopenia
- Bradycardia, postural hypotension, arrhythmia
- Dry skin, sometimes orange (hypercarotinaemia)
- Brittle hair/nails
- Lanugo on back, forearms, cheeks
- Peripheral oedema
- Proximal myopathy
- Osteoporosis/osteopaenia
- Poorly developed 2ry sexual characteristics
Endocrine abnormalities in anorexia nervosa
Low: LH, FSH, T3, estradiol
High: Cortisol, GH
Metabolic abnormalities in anorexia nervosa
Hypoglycaemia
Hypercholesterolaemia
Electrolyte abnormalities in anorexia nervosa
Hyponatraemia, hypokalaemia, metabolic alkalosis
MAY PRESENT AS ASYMPTOMATIC HYPOGLYCAEMIA DUE TO RESERVE
ECG abnormality in anorexia nervosa
Prolonged Q-T interval, arrhythmias, bradycardia
Physical signs in bulmia nervosa
- Pitted teeth
- Calluses on knuckles (Russell’s sign)
- Enlarged salivary glands
- Hoarse voice
Blood abnormalities in bulimia nervosa
Renal dysfunction, electrolyte abnormalities from diuretics
Metabolic alkalosis from vomiting
Colonic hypomotolity from laxatives
Psychiatric differential for anorexia
- Depressive disorder
- OCD
- Body-dysmorphic disorder
- Substance misuse
Physical differential for anorexia
- IBD, IBS
- Diabetes insipidus/mellitus
- Hypopituitarism
- Pituitary brain tumour (headache + non-induced vomiting)
- Cancer
- Malabsorption syndromes
- Amphetamine use
Differential for bulimia
- Binge-eating disorder
- Atypical depression (psychogenic overeating)
- Anorexia nervosa
- Medical causes of vomiting
Short-term management of anorexia nervosa
- Physical + psychosocial assessment –> assess immediate risk to consider admission to hospital
- If moderate anorexia –> secondary care referral
- Slowly begin refeeding –> monitor electrolytes prior to refeeding and regularly to avoid refeeding syndrome
- Use Pabrinex, multivitamin supplements
- Agree on goals/need for treatment to work towards
- aim for 0.5-1kg weight gain per week
- Psychoeducation + self-help resources
Long-term management of eating disorders
CBT
Family therapy (esp in adolescents)
Regular physical monitoring (electrolytes, height, weight, dental review)
Use of nutritional supplements (e.g. multivitamins)
Monitor drugs (esp for prolonged Q-T)
Weight gain 0.5-1kg per week) –> improves psychopathology
Consider SSRI (for BN/BED, or comorbidity)
Risk factors for refeeding syndrome
Low initial electrolytes
BMI <13
Significant comorbidity (intercurrent infection, alcoholism, uncontrolled diabetes, cardiac failure)
Criteria for considering admission to hospital for AN
- Risk of suicide/severe self-harm
- Home environment impedes recovery
- Rapid weight loss, BMI <15
- Bradycardia, hypoglycaemia, severe intercurrent infeciton, pronounced oedema, electrolyte abnormalities
Components of hospital management of severe eating disorder
- Medical: life-saving treatment, refeeding + avoid refeeding syndrome, manage complications
- Psychological: intensive individual, family, and group therapy
Treatment of bulimia nervosa
- Self-help programmes
- CBT: Break vicious cycle between bingeing, purging + preoccupation with weight + shape
- interpersonal therapy (emphasises the role of relationships, takes longer)
- Trial of fluoxetine (high doses needed, 60mg)
Success rate of CBT in bulimia
60-70% disease-free at 5 years
Prognosis for BN
30% residual symptoms at 10y
Evidence unclear
Poor prognostic factors for bulimia
Low self-esteem
premorbid hildhood obesity
Co-morbid personality disturbance
long duration prior to prersentation
Poor prognostic factors in anorexia
Long duration prior to presentation
Adult onset (20-29)
Severe weight loss (ost prognostic)
Vomiting/purging subtype
10-year mortality of anorexia nervosa
10-20%
60% due to starvation (mainly cardiac failure due to dilation/thin walls, reversible with weight gain)
27% due to suicide
Anorexia red flags that raise risk
- BMI <13
- ECG: Long Q-T or flattened T-waves
- Skin: purpura
- Vascular: BP <80/50, pulse <40, Sats <92%
- Temperature <34.5
- Wt loss >1kg/week
- Electrolyte abnormalities
- Proximal myopathy (not using arms for leverage unable to get up
Signs of refeeding syndrome
- Falling PO4, K+, Mg2+
- Falling BP
- Rhabdomyolysis
- Cardiac/respiratory failure
- Arrhythmias
- Seizures
Prognosis for anorexia nervosa
1/3 complete recovery
1/3 partial recovery
1/3 chronic illness
0.5% mortality per year
Psychosocial assessment in suspected eating disorder
- Motivation to change eating habits
- Causes of eating habits
- Views on consequences of eating habits
- Suicide risk
- Psychiatric comorbidities: Depression, OCD, anxiety
Physical assessment in suspected eating disorder
- Height + weight
- Core body temperature
- Cardiovascular incl. postural drop
- Muscle power
- Skin signs
Questions to ask about weight control behaviours
- Typical day’s dietary intake
- Exercise: type and frequency
- Induced vomiting
- Laxatives, diuretics (incl. coffee), amphetamines
- Binges: loss of control + feelings afterwards
Questions to ask about attitude to weight + shape
- Current weight + frequency of weighing behaviour
- How do you feel about your body shape/weight?
- How would you feel if you were a size bigger?
- Do you think you’re fat?
- Have other people said you’re thin? Do you believe them
Screening questions for eating disorder
SCOFF (>2=further assessment)
- Do make yourself SICK?
- Do you feel like you’ve lost CONTROL of your eating?
- Have you lost more than ONE stone (6-7kg) in the last 3 months?
- Do you think you’re FAT even when others tell you you’re thin?
- Do you often think about FOOD?
Anorexia nervosa subtype with worse mortality
Binge-purging
Co-morbidity in AN
40-60% depression
Also anxiety, OCD, PD
