What physical examination findings are expected in a patient with anorexia nervosa?

Physical Examination Findings in Anorexia Nervosa

In a 16-year-old girl with suspected anorexia nervosa presenting with rapid weight loss and a BMI of 17.8, you should expect to find vital sign abnormalities (bradycardia, hypotension, hypothermia, orthostatic changes), signs of malnutrition (muscle wasting, loss of subcutaneous fat), and potentially cardiac complications on examination. 1

Vital Sign Abnormalities

The most consistently documented physical findings in anorexia nervosa involve vital sign derangements:

• Bradycardia occurs in approximately 41% of outpatients with anorexia nervosa and is one of the most common cardiac manifestations 2
• Hypotension is present in about 16% of cases 2
• Hypothermia affects approximately 22% of patients 2
• Orthostatic pulse and blood pressure changes should be assessed at every evaluation, as they indicate cardiovascular instability and dehydration 1, 3

The American Psychiatric Association specifically recommends measuring temperature, resting heart rate, blood pressure, orthostatic pulse, and orthostatic blood pressure as essential components of the initial physical examination 1.

Signs of Malnutrition

Physical examination should focus on identifying tissue wasting:

• Muscle wasting can be assessed by examining the temporalis muscle, prominence of clavicles, contour of shoulders (squared indicates malnutrition versus rounded for well-nourished), visibility of scapula and ribs, interosseous muscle mass between thumb and forefinger, and quadriceps muscle mass 1
• Loss of subcutaneous fat is evaluated by examining fat pads directly below the eyes (appearing "hollow" rather than as a slight bulge) and by gently pinching skin above the triceps and biceps to assess fold thickness 1
• Hair changes including alopecia, hair thinning, and fine lanugo-like hair growth on the face due to malnutrition 3

Signs Related to Purging Behaviors

Even in restrictive-type anorexia nervosa, assess for:

• Parotid gland enlargement appearing as swollen cheeks or jawline, which is pathognomonic for purging behavior (Russell's sign) 3
• Dental erosion and poor gum health from repeated acid exposure if any purging occurs 3

However, the British Journal of Sports Medicine notes that good dentition and thick hair would be inconsistent with eating disorders 3.

Cardiac Examination Findings

The cardiovascular system requires particular attention given that up to one-third of deaths in anorexia nervosa are cardiac-related 4:

• Sinus bradycardia is the most common electrocardiographic finding 4
• QTc interval prolongation predicts risk of sudden cardiac death and should be monitored with serial ECGs in patients with restrictive eating 1, 3, 5
• Pericardial effusion may be present and correlates with the rapidity of weight loss (Delta BMI) rather than absolute weight 6
• Cardiac muscle atrophy results from prolonged starvation 4

The American Psychiatric Association recommends performing an electrocardiogram in all patients with restrictive eating disorders 1.

Critical Clinical Caveat

Approximately 60% of patients with anorexia nervosa show normal laboratory values despite severe malnutrition 4. The rapid rate of weight loss appears more predictive of complications than the absolute amount of weight loss 6. In this patient's case, the 6-month timeframe of "rapid weight loss" is particularly concerning for cardiac complications, as Delta BMI (change in BMI Z-score) correlates with low systolic blood pressure and presence of pericardial effusion 6.

Additional Physical Findings

Beyond the core examination:

• Weight and BMI documentation is essential, with this patient's BMI of 17.8 indicating undernutrition 1
• Anemia is present in approximately 39% of outpatients 2
• Leukocytopenia occurs in about 34% of cases 2

The physical examination findings in anorexia nervosa reflect both the direct effects of malnutrition and the physiological adaptations to starvation. Most cardiac manifestations are completely reversible with appropriate nutritional rehabilitation 4, making early identification and treatment critical for preventing long-term morbidity and mortality.