Bulimia Nervosa

Definition | Aetiology | Risk Factors | Clinical Presentation | Investigations | Management | When to Refer | References

Definition

Bulimia Nervosa is a serious eating disorder characterised by recurrent episodes of binge eating followed by compensatory behaviours, such as self-induced vomiting, misuse of laxatives, fasting, or excessive exercise, to prevent weight gain. Individuals with bulimia nervosa often have a distorted body image and a strong preoccupation with body weight and shape.

Aetiology

The exact cause of bulimia nervosa is not fully understood, but it is believed to result from a combination of genetic, biological, psychological, and environmental factors:

• Genetic Factors: A family history of eating disorders or other mental health conditions may increase the risk, suggesting a genetic predisposition.
• Biological Factors: Neurobiological abnormalities, including imbalances in neurotransmitters such as serotonin, may contribute to the development of bulimia.
• Psychological Factors: Low self-esteem, perfectionism, and impulsivity are common psychological traits associated with bulimia nervosa.
• Environmental Factors: Societal pressures, cultural ideals of thinness, and exposure to dieting or weight-related teasing can contribute to the development of bulimia.
• Trauma: A history of trauma, such as abuse or significant loss, may also play a role in the onset of bulimia nervosa.

Risk Factors

Several factors increase the likelihood of developing bulimia nervosa:

• Gender: Females are more commonly affected than males, though the incidence in males is rising.
• Age: Bulimia nervosa typically begins in adolescence or early adulthood, though it can occur at any age.
• Family History: Having a close relative with an eating disorder, depression, or substance abuse increases the risk.
• Personality Traits: Traits such as impulsivity, perfectionism, and low self-esteem are often seen in individuals with bulimia.
• Dieting and Weight Concerns: Engaging in dieting or weight control behaviours, particularly during adolescence, can increase the risk of developing bulimia.
• Societal Pressures: Exposure to cultural ideals of thinness and the promotion of unrealistic body standards in the media.

Clinical Presentation

Bulimia nervosa presents with a range of psychological, behavioural, and physical symptoms:

Psychological and Behavioural Symptoms

• Binge Eating Episodes: Recurrent episodes of eating an excessive amount of food in a discrete period, often accompanied by a sense of loss of control.
• Compensatory Behaviours: Recurrent inappropriate behaviours to prevent weight gain, such as self-induced vomiting, misuse of laxatives or diuretics, fasting, or excessive exercise.
• Distorted Body Image: A perception of being overweight, even when at a healthy weight, and an intense preoccupation with body shape and weight.
• Secrecy and Shame: Behaviours are often performed in secret, leading to feelings of shame, guilt, and distress.
• Mood Swings: Individuals may experience mood swings, irritability, anxiety, or depression.
• Social Withdrawal: Avoidance of social situations, particularly those involving food, due to fear of eating or being judged.

Physical Symptoms

• Fluctuations in Weight: Frequent changes in weight, though individuals with bulimia nervosa often maintain a weight within the normal range.
• Gastrointestinal Issues: Chronic sore throat, acid reflux, or gastrointestinal distress due to frequent vomiting or laxative abuse.
• Dental Erosion: Erosion of tooth enamel due to repeated exposure to stomach acid from self-induced vomiting.
• Swollen Salivary Glands: Enlargement of the salivary glands, particularly the parotid glands, often resulting in a "chipmunk cheek" appearance.
• Calluses on the Knuckles: Known as "Russell's sign," these are caused by repeated contact with teeth during self-induced vomiting.
• Electrolyte Imbalances: Imbalances, particularly low potassium levels, which can lead to serious complications such as cardiac arrhythmias or heart failure.
• Fatigue and Weakness: General feelings of tiredness and lack of energy, often due to malnutrition or electrolyte disturbances.

Investigations

The diagnosis of bulimia nervosa is primarily clinical, based on a detailed history and physical examination. Additional investigations are often required to assess the physical complications of the disorder:

• Blood Tests: Full blood count (FBC), electrolytes, renal function tests, and liver function tests (LFTs) to assess for malnutrition-related complications and electrolyte imbalances.
• Electrocardiogram (ECG): To detect cardiac abnormalities such as arrhythmias that may result from electrolyte imbalances or prolonged vomiting.
• Dental Examination: Assessment by a dentist to evaluate the extent of dental erosion and other oral health issues.
• Psychiatric Assessment: A comprehensive mental health evaluation to assess for co-occurring mental health conditions such as depression, anxiety, or substance abuse.
• Nutritional Assessment: Evaluation of dietary intake and nutritional status by a dietitian to guide nutritional rehabilitation.

Management

The management of bulimia nervosa requires a multidisciplinary approach involving medical, nutritional, and psychological interventions:

Medical Management

• Monitoring and Management of Medical Complications: Regular monitoring of vital signs, electrolytes, and cardiac function to manage complications such as electrolyte imbalances and arrhythmias.
• Pharmacotherapy: Selective Serotonin Reuptake Inhibitors (SSRIs), particularly fluoxetine, are the first-line pharmacological treatment for bulimia nervosa and can help reduce binge-purge cycles and associated mood symptoms.

Psychological Therapies

• Cognitive Behavioural Therapy (CBT): The most effective psychological treatment for bulimia nervosa, focusing on changing distorted beliefs about body image, weight, and food, and developing healthier eating behaviours.
• Interpersonal Therapy (IPT): Addresses interpersonal issues that may contribute to the development or maintenance of bulimia nervosa.
• Dialectical Behaviour Therapy (DBT): May be used to help individuals with emotional regulation and reduce impulsive behaviours such as binge eating and purging.
• Family-Based Therapy (FBT): Particularly useful for adolescents, FBT involves the family in supporting the individual’s recovery and managing eating behaviours.

Nutritional Rehabilitation

• Dietitian Involvement: A registered dietitian can provide a structured meal plan, education on balanced nutrition, and support for normalising eating patterns.
• Addressing Malnutrition: Gradual reintroduction of a balanced diet to correct nutritional deficiencies and promote healthy weight stabilisation.
• Monitoring Nutritional Intake: Close monitoring of food intake, weight, and physical health to ensure progress and prevent complications.

When to Refer

Referral to a specialist eating disorder service or inpatient treatment may be necessary in the following situations:

• Severe electrolyte imbalances or cardiac complications requiring hospitalisation.
• Failure to respond to outpatient treatment or worsening of symptoms despite intervention.
• Presence of co-occurring mental health conditions such as severe depression, anxiety, or suicidality that require intensive treatment.
• Need for specialised psychological therapies, such as CBT or DBT, that are not available in primary care settings.
• Significant physical health risks, including severe malnutrition or weight loss.

References

1. NHS (2024) Bulimia Nervosa. Available at: https://www.nhs.uk/conditions/bulimia/ (Accessed: 26 August 2024).
2. National Institute for Health and Care Excellence (2024) Eating Disorders: Recognition and Treatment. Available at: https://www.nice.org.uk/guidance/ng69 (Accessed: 26 August 2024).
3. British Medical Journal (2024) Bulimia Nervosa: Clinical Review. Available at: https://www.bmj.com/content/350/bmj.h3725 (Accessed: 26 August 2024).

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