Makindo Medical Notes

📖 About

• Bulimia Nervosa is characterized by recurrent episodes of binge eating, typically followed by compensatory behaviours such as vomiting, fasting, or excessive exercise.

🧑‍⚕️ Clinical Features

• Often normal or low body mass but with recurrent purging.
• Poor dentition with marked dental erosion due to gastric acid exposure.
• Dehydration, halitosis, and dental caries.
• Enlarged salivary glands (sialadenosis) from repeated vomiting.
• Calluses on the back of the hand (“Russell’s sign”) from induced vomiting.

🔍 Differential Diagnoses

• Binge Eating Disorder (without compensatory behaviours).
• Anorexia Nervosa (binge–purge subtype).
• Other psychiatric disorders with abnormal eating (e.g., depression, borderline personality disorder).
• Gastrointestinal conditions causing vomiting or weight loss.

🧪 Investigations

• Low Urea: Suggestive of low body mass.
• Mild Hypocalcaemia: Secondary to nutritional deficiencies.
• Metabolic Alkalosis: Elevated HCO₃ from vomiting.
• Electrolyte Imbalances: Hypokalaemia and hyponatraemia common with purging.
• Urine Sodium: Appropriately low with concentrated urine (reflecting dehydration).
• ECG: May show prolonged QTc or arrhythmias due to electrolyte imbalance.

📑 Clinical Criteria for Binge Eating Episodes

• Binge Eating:
  • Eating, within a discrete period (e.g. 2 hours), an amount of food significantly larger than most people would eat.
  • Feeling a lack of control during the episode.
• Compensatory Behaviours: Vomiting, laxatives, diuretics, enemas, fasting, or excessive exercise.
• Frequency & Duration: At least twice per week for 3 months.
• Self-Evaluation: Body weight/shape unduly influences self-worth.
• Exclusion: Not occurring exclusively during episodes of anorexia nervosa.

🔄 Types of Bulimia Nervosa

• Purging Type: Regular self-induced vomiting, or misuse of laxatives, diuretics, or enemas.
• Non-Purging Type: Compensatory behaviours such as fasting or excessive exercise, without regular purging.

💡 Teaching Pearl

💭 Think “teeth, throat, and potassium”: acid erosion of teeth, throat soreness from vomiting, and hypokalaemia on bloods are classic exam clues for bulimia nervosa.