What should be done for a girl with a potential eating disorder, who is misusing diuretics and not eating well?

Immediate Evaluation and Management of Suspected Eating Disorder with Diuretic Misuse

This girl requires urgent medical evaluation with vital signs, orthostatic measurements, ECG, and comprehensive metabolic panel to assess for life-threatening electrolyte abnormalities and cardiac complications from diuretic abuse, followed by immediate referral to a multidisciplinary eating disorder team. 1, 2

Critical Initial Assessment

The discordance between the girl's self-report ("I am well") and her mother's concern, combined with an empty diuretic bottle, represents a classic presentation of eating disorder denial and high-risk purging behavior. 1

Immediate Medical Evaluation Required

Obtain vital signs at this visit to identify medical instability: 1, 2, 3

• Temperature (hypothermia <36°C indicates severe malnutrition requiring hospitalization) 4
• Resting heart rate (bradycardia <50 bpm daytime or <45 bpm nighttime requires admission) 4
• Blood pressure and orthostatic measurements (orthostatic hypotension or tachycardia indicates cardiovascular compromise) 2, 4
• Height, weight, and BMI compared to previous growth chart data (rapid decline or BMI <5th percentile suggests eating disorder) 1

Emergency Laboratory Testing

Order immediately: 2, 3

• Comprehensive metabolic panel to detect hypokalemia, hyponatremia, hypochloremic alkalosis from diuretic abuse 2, 3, 5
• Complete blood count for anemia, leukopenia, thrombocytopenia 2, 3
• ECG to assess QTc prolongation (predicts sudden cardiac death risk) 2, 4

Critical pitfall: Diuretic abuse can cause severe, life-threatening hyponatremia (as low as 91 mEq/L reported), which if corrected too rapidly can cause central pontine myelinolysis. 5 Normal laboratory values do NOT exclude serious illness—approximately 60% of anorexia nervosa patients show normal values despite severe malnutrition. 2

Physical Examination Findings to Document

Look specifically for: 1, 3

• Parotid gland enlargement (swollen cheeks/jawline from purging) 3
• Russell's sign (calluses on knuckles from self-induced vomiting) 2, 3
• Dental erosion (from gastric acid exposure) 3
• Lanugo hair (fine body hair from malnutrition) 3

Hospitalization Criteria—Assess Immediately

Admit to hospital if ANY of the following are present: 4

• Heart rate <50 bpm (daytime) or <45 bpm (nighttime) 4
• Orthostatic vital sign changes 4
• Temperature <36°C 4
• QTc prolongation on ECG 4
• Severe electrolyte abnormalities (particularly hypokalemia, hyponatremia) 2, 5
• Weight <75% ideal body weight or BMI <16 kg/m² 4
• Inability to control purging behaviors 4

For adolescents, apply MORE aggressive hospitalization criteria at higher weight percentiles than adults, as early aggressive treatment provides the best prognosis. 4

Psychiatric Assessment

Screen for: 1, 3

• Suicidality (25% of anorexia nervosa deaths are from suicide; eating disorders have the highest mortality of any psychiatric disorder) 2, 3
• Comorbid depression, anxiety, obsessive-compulsive disorder 3
• History of physical or sexual abuse 3
• Degree of denial and insight into illness 3

Treatment Approach

If Medically Stable for Outpatient Management

Refer immediately to multidisciplinary eating disorder team including: 1, 2

• Psychiatrist or psychologist for eating disorder-focused psychotherapy 2
• Registered dietitian experienced in eating disorders 1, 2
• Medical provider for ongoing monitoring 1, 2

For adolescents with involved caregivers, family-based treatment (FBT) is first-line therapy. 2, 4 In FBT, parents take responsibility for weight restoration while separating the child from the illness using a non-authoritarian approach. 1

If Medically Unstable

Hospitalize for medical stabilization before specialized eating disorder treatment: 4

• Initiate slow, cautious refeeding with phosphorus supplementation to prevent fatal refeeding syndrome 2, 4
• Monitor QTc intervals serially 2
• Correct electrolytes slowly (sodium correction <0.55 mEq/L/hour to prevent central pontine myelinolysis) 5
• Nasogastric or IV nutrition may be required if oral intake insufficient 2

Critical Management Principles

Do NOT delay intervention based on patient denial—eating disorders are life-threatening conditions requiring aggressive early intervention. 2 The girl's statement that she is "well" is characteristic of the illness itself and should not reassure you. 1

Diuretic abuse specifically places her at risk for: 5, 6

• Severe hyponatremia with risk of seizures and central pontine myelinolysis 5
• Hypokalemia with cardiac arrhythmia risk 6
• Renal dysfunction 6

Early diagnosis and intervention are associated with improved outcomes. 1 Most medical complications are reversible with nutritional rehabilitation and cessation of purging behaviors, but cardiac complications can cause sudden death before treatment begins. 2, 7