Behavioral Sciences 1 out of 244
A 16-year-old girl is brought to the physician because her mother is concerned about her lack of appetite and poor weight gain. She has had a 7-kg (15-lb) weight loss over the past 3 months. The patient states that she should try to lose more weight because she does not want to be overweight anymore. She maintains a diary of her daily calorie intake. Menarche was at the age of 13 years, and her last menstrual period was 3 months ago. She is on the high school track team. She is sexually active with 2 male partners and uses condoms inconsistently. She is at the 50th percentile for height and below the 5th percentile for weight and BMI. Her temperature is 37.0°C (98.6°F), pulse is 58/min and blood pressure is 96/60 mm Hg. Examination shows fine hair over the trunk and extremities. Which of the following is the most likely diagnosis?
Obsessive compulsive disorderPatients with obsessive compulsive disorder (OCD) can also present with obsessions and compulsions regarding food intake but are usually not significantly underweight. OCD does commonly coexists with other illnesses such as substance abuse or eating disorders. Type 1 diabetes mellitusWhile type 1 diabetes mellitus may also present with weight loss and a thin appearance, this patient lacks further symptoms such as polyuria, polydipsia, and polyphagia. Moreover, the age of onset of type 1 DM is typically before adolescence. This girl's attitude about her body image, menstrual abnormalities, and lanugo hair suggest a different diagnosis.
Body dysmorphic disorderPatients with body dysmorphic disorder may be obsessed and concerned with their physical appearance, but the concerns typically involve features of the face or head (e.g., nose size) and not the body weight. Moreover, body dysmorphic disorder does not manifest with significant weight loss and lanugo hair. Anorexia nervosaThis patient's presentation of a BMI below the 10th percentile for her height and age, fear of gaining weight, and body image disturbance (“not be overweight anymore”) indicate anorexia nervosa, a condition mainly affecting adolescent girls and young women, and often resulting in lanugo hair and secondary amenorrhea. Weight loss is achieved intentionally either through reduced food intake and/or excess physical activity (restrictive type) or by vomiting or laxative abuse (binge-eating/purging type). Severe complications include refeeding syndrome, osteoporosis and stress fractures, electrolyte imbalances, arrhythmias, and sudden cardiac death. Anorexia nervosa is also associated with other psychological conditions (e.g., depression, obsessive-compulsive disorder, anxiety disorders) and a higher rate of suicide.
The most important acute therapeutic measure is a stepwise increase in food intake to counteract life-threatening cachexia. Long-term treatment involves ensuring the patient's stable condition through psychotherapy and education. Bulimia nervosaWhile bulimia nervosa also mostly affects young women that are counteracting weight gain and have a distorted self-perception, it is mainly characterized by a normal or increased BMI > 10th percentile for gender and age and generally has its onset in late adolescence or early adulthood. HyperthyroidismWhile hyperthyroidism may also manifest with weight loss and amenorrhea, this patient lacks a goiter and further symptoms of a hypermetabolic state such as heat intolerance (sweating), palpitations (tachycardia), and diarrhea (increased bowel movements). This patient's condition rather manifests with a hypometabolic state, hypotension, and bradycardia to conserve limited resources. Additionally, this girl's attitude about her body image suggests a different diagnosis. HIV infectionWhile an HIV infection may also manifest with weight loss, this patient lacks further symptoms of an acute or latent HIV infection such as fever, fatigue, myalgia, generalized rash, oral thrush, nontender lymphadenopathy, diarrhea, and/or HIV-associated conditions. Moreover, patients with HIV usually do not fear gaining weight and do not have a distorted body image. Since this patient is sexually active with 2 male partners and uses condoms inconsistently, it is important to screen for sexually transmitted diseases.
Back Next