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Anorexia Nervosa in PLAB 2- Symptoms, Red Flags, Key Questions, and Structured Managem

What is Anorexia Nervosa?

Anorexia nervosa is an eating disorder characterized by:

  • Restrictive eating

  • Fear of gaining weight

  • Distorted body image

  • Low body weight

Patients often have poor insight and may not recognize the seriousness of their illness.


Common Symptoms and Signs


Weight and Eating Behaviors

  • Significant weight loss

  • Skipping meals

  • Calorie counting

  • Avoiding carbohydrates/fats

  • Excessive exercise

  • Fear of weight gain

Typical patient statements:

  • “I still feel fat.”

  • “I feel guilty after eating.”

  • “I panic if I miss exercise.”



Physical Symptoms

  • Fatigue

  • Feeling cold

  • Dizziness/syncope

  • Constipation

  • Hair thinning

  • Amenorrhea



Examination Findings

  • Low BMI

  • Bradycardia

  • Hypotension

  • Postural drop

  • Lanugo hair

  • Dry skin

  • Muscle wasting



Structured History Taking


1. Weight History

  • “When did the weight loss begin?”

  • “How much weight have you lost?”

  • “Do you have a target weight?”


2. Eating Habits

  • “What do you eat in a typical day?”

  • “Do you avoid certain foods?”

  • “Do you count calories?”

  • “Do you skip meals?”


3. Body Image

  • “How do you feel about your body shape?”

  • “Do you feel overweight?”

  • “How do you feel when you look in the mirror?”


4. Exercise Behaviors

  • “How often do you exercise?”

  • “How do you feel if you miss exercise?”


5. Purging Behaviors

  • “Do you ever make yourself sick after eating?”

  • “Do you use laxatives, diuretics, or slimming tablets?”



SCOFF Questionnaire

SCOFF Questionnaire


S — Sick

“Do you make yourself sick because you feel uncomfortably full?”


C — Control

“Do you worry you have lost control over eating?”


O — One Stone

“Have you lost more than one stone recently?”


F — Fat

“Do you think you are fat when others say you are too thin?”


F — Food

“Would you say food dominates your life?”


Interpretation

Score ≥2 → likely eating disorder requiring further assessment.



Mental Health and Risk Assessment


Mood and Anxiety

  • “How has your mood been?”

  • “Do you feel anxious around food?”


Suicide Risk

  • “Have you had thoughts of harming yourself?”

  • “Have you felt life is not worth living?”



Important Red Flags

These may warrant urgent specialist assessment or admission.


Cardiovascular

  • Bradycardia

  • Hypotension

  • Syncope

  • Chest pain

  • Palpitations

  • QT prolongation


Nutritional

  • Rapid weight loss

  • Severe dehydration

  • Refusal to eat/drink

  • Severe weakness


Electrolyte Abnormalities

  • Hypokalemia

  • Hypophosphatemia

  • Hypomagnesemia


Psychiatric

  • Suicidal thoughts

  • Severe depression

  • Self-harm

  • Severe self-neglect



Refeeding Syndrome (Very Important)

Refeeding Syndrome may occur when feeding is restarted too quickly.


Features

  • Hypophosphatemia

  • Arrhythmias

  • Confusion

  • Heart failure


Prevention

  • Slow supervised refeeding

  • Thiamine supplementation

  • Electrolyte monitoring



Severity Classification and Management

Severity

BMI

Management

Mild

≥17

Outpatient management, CBT-ED/CBT-E, dietitian referral, monitoring

Moderate

16–16.9

Specialist follow-up, closer monitoring, intensive outpatient/day care

Severe

15–15.9

Urgent specialist assessment, possible admission, ECG and electrolyte monitoring

Extreme

<15

High medical risk, likely inpatient admission, supervised refeeding



Admission May Be Needed At Any BMI If:

  • Bradycardia

  • Hypotension

  • Syncope

  • Electrolyte abnormalities

  • Refusal to eat/drink

  • Rapid deterioration

  • Suicide risk

  • Severe weakness

  • High refeeding risk



Investigations


Blood Tests

  • FBC

  • U&E

  • LFT

  • TFT

  • Glucose

  • Magnesium

  • Phosphate

  • Calcium


ECG

Assess for:

  • Bradycardia

  • QT prolongation

  • Arrhythmias



Structured Management


1. Explain the Diagnosis

Explain simply that concerns about food and weight are affecting both physical and mental health.


2. Nutritional Management

  • Encourage regular balanced meals

  • Dietitian referral

  • Food diary

  • Gradual nutritional rehabilitation


3. Psychological Treatment

Adults

First-line:

  • Eating-disorder-focused Cognitive Behavioral Therapy (CBT-ED / CBT-E)

Adolescents

  • Family-based therapy



Medication

No medication directly treats anorexia nervosa itself.

Sometimes used:

  • Fluoxetine

  • Olanzapine

for:

  • Depression

  • Anxiety

  • Obsessive symptoms



Lifestyle Advice

  • Reduce excessive exercise

  • Smoking cessation

  • Improve sleep

  • Encourage family support



Safety Netting

Seek urgent medical help if:

  • Chest pain

  • Palpitations

  • Fainting

  • Severe weakness

  • Confusion

  • Persistent vomiting

  • Suicidal thoughts



Important PLAB 2 Communication Tip

Patients are often ambivalent.

Example:

“Part of you may feel these habits help you stay in control, while another part may recognize they’re affecting your health.”

This demonstrates empathy and insight.



High-Yield PLAB/MSRA Pearls


Underweight + fear of weight gain + distorted body image

→ Think anorexia nervosa.


Amenorrhea + excessive exercise + food restriction

→ Strongly suggestive.


Hypophosphatemia after feeding

→ Think refeeding syndrome.


BMI alone does not determine severity.

Always assess:

  • vitals,

  • ECG,

  • electrolytes,

  • psychiatric risk,

  • and functional impairment.


📚 References

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