Eating disorders are common and dangerous conditions. They affect millions of Americans, across all racial and socioeconomic lines, occurring in both males and females. Eating disorders consistently challenge patients, families, and medical professionals.¹ The management of eating disorders, whether treatment is in an inpatient or outpatient setting, requires a coordinated multidisciplinary team of individuals—ideally consisting of a physician (the patient’s primary care physician if he or she is comfortable in that role, a physician specializing in eating disorders, or a hospitalist physician), a registered dietician, a mental health provider, and a caregiver or parent.² Although most patients with eating disorders are managed in an outpatient setting, this chapter provides a practical framework for the general pediatrics hospitalist to stabilize and initiate management of a patient hospitalized for an eating disorder.

EPIDEMIOLOGY

Eating disorders pose a considerable public health concern and are associated with severe medical and psychiatric morbidity.^3,4 Eating disorders are increasing in incidence and prevalence, and thus being diagnosed in adolescents with increasing frequency.⁵ Therefore it is of paramount importance that pediatricians and hospitalists are familiar with how to best detect and subsequently manage these disorders.¹

The three major subgroups of eating disorders described in the literature are defined in the Diagnostic and Statistical Manual of Mental Disorders Fourth edition (DSM-IV) as anorexia nervosa (AN), bulimia nervosa (BN), and eating disorder not otherwise specified (EDNOS).⁵ These diagnostic categories and criteria have recently been updated in the DSM-5, as described later in this text.⁶ AN is estimated to affect 1% of adolescents and young adults, while BN has a higher prevalence of 3%.⁷ The majority of adolescents and adults presenting for eating disorder treatment are diagnosed with EDNOS,⁸ with an estimated prevalence between 0.8% and 14%.⁹ In addition, disordered eating behaviors are very common, with up to 25% of high school girls and 11% of boys reporting disordered eating severe enough to need evaluation, and 9% of high school girls and 4% of boys induce vomiting to control their weight.⁷

Females account for the majority of cases of AN and BN, but these disorders also occur in males. Males with eating disorders are increasing in prevalence, ranging from 10% to 25% of reported cases¹ in recent reports. Eating disorders occur in all races and socioeconomic strata.^10-12 Although the exact etiology of these disorders is unknown, they are thought to be multifactorial in origin, with strong evidence for neurobiological predispositions and gene–environment interactions.^13,14

A patient presenting with weight loss, poor growth, pubertal cessation, restrictive attitudes about weight, unexplained vomiting, or abnormal eating behaviors should prompt a consideration of the diagnosis of eating disorder. AN usually presents with a refusal to maintain a minimally normal body weight. BN classically presents as recurrent episodes of binge eating followed by unhealthy behaviors to avoid weight gain, such as induced vomiting or laxative use.¹⁵ The consequences of the weight loss or purging activity can lead to medical instability requiring hospitalization, even though these signs may not be obvious on initial presentation. Presenting signs and symptoms (Table 44-1) may include syncope, hematemesis, orthostatic hypotension, chest pain, menstrual irregularities or other symptoms of hypogonadism, and constipation, to name a few.^1,16-18 Some patients with eating disorders are overweight or obese and may therefore not be recognized. Similarly, eating disorders are often missed in adolescent males at first presentation, and it is important to consider these diseases when boys present with symptoms that may reflect an eating disorder. Younger patients (for example, pre-teens) with eating disorders may also present in a more atypical manner. Some may not lose weight, but may instead fail to grow in either weight and/or height.⁷

ANOREXIA NERVOSA

For a patient with anorexia nervosa, restriction of energy intake leading to a weight that is significantly low for developmental stage is essential to the clinical picture. Other diagnostic criteria involve either a fear of weight gain or behaviors that persistently sabotage weight gain. Amenorrhea is no longer a criterion in the DSM-5.⁶ There is often a history of overactivity or excessive exercise. Many patients also exhibit elaborate rituals pertaining to food or an intense interest in para-eating behaviors, such as collecting recipes, preparing food for the family, or watching food-related television programs. Patients often have an unrealistic perception of their body image and display little concern over their weight loss, and actually often report that they “feel fine.” They are often described as being excellent students or overachievers, possibly related to a genetic predisposition to a myriad of trait disturbances including behavioral rigidity and perfectionism.^13,14,19 Postmenarchal females with anorexia nervosa may be amenorrheic, and premenarchal children may have delayed linear growth. Patients may have some of the following physical complaints: early satiety; abdominal bloating, post-prandial discomfort, or pain; nausea or vomiting; constipation; dizziness or fainting; cold intolerance; dry or yellow skin; fatigue, weakness, or muscle cramps.²⁰

BULIMIA NERVOSA

The key distinguishing feature of bulimia nervosa is repeated episodes of binge eating. These episodes are characterized by (1) the consumption of an amount of food in a fixed period that is larger than what most people would eat and (2) a sense of loss of control over the eating episode. In response to an episode of bingeing, the individual often displays maladaptive behaviors to prevent weight gain. These behaviors take one of two forms: (1) purging: the patient engages in self-induced vomiting or the use of laxatives, enemas, or diuretics, or (2) nonpurging: the patient engages in fasting or excessive exercise as compensatory methods. An individual with bulimia is usually aware that his or her eating pattern is abnormal and may go to great lengths to conceal it.^{1,16-18,21-24}

BINGE-EATING DISORDER

Binge-eating disorder is characterized by binge-eating episodes as described in BN, but without any episodes of purging. Binge-eating disorder, while a debilitating and common disorder, rarely requires inpatient medical stabilization, so is not discussed in detail in this chapter.^1,16-18,21

AVOIDANT-RESTRICTIVE FOOD INTAKE DISORDER

Another newer category in the DSM-5 is Avoidant-Restrictive Food Intake Disorder (ARFID). ARFID is meant to encompass restrictive eating disorders that do not involve a fear of weight gain or distorted cognitions but cause significant physical and emotional impairment. ARFID can include but is not limited to swallowing, vomiting, and choking phobias, highly selective eating, and textural aversions that reach a level of clinical significance.^21-24

OTHER SPECIFIED FEEDING AND EATING DISORDERS AND UNSPECIFIED FEEDING AND EATING DISORDERS

These two diagnostic categories are meant to further differentiate subgroups within what used to be characterized as “eating disorders not otherwise specified” (EDNOS) in the DSM-IV. EDNOS was a problematic category, as 60% to 80% of treatment populations would meet criteria for EDNOS rather than AN or BN, and thus it was a very common but heterogeneous diagnostic group.²⁵ The DSM-5 has attempted to rectify this by introducing “Other Specified Feeding and Eating Disorders” (OSFED), which refers to atypical AN, subthreshold BN and binge-eating disorder, purging disorder, and night-eating syndrome.²⁶ Unspecified feeding and eating disorders is a category that now contains eating disorders considered to be clinically significant but which do not fall into these other categories.

It is important to note that eating disorders that do not meet full criteria for AN or BN can nonetheless cause significant medical compromise and psychiatric morbidity.²⁵ They require equally aggressive care, both medically and psychologically, and have been shown to have poor outcomes if not treated early.^21-24

The initial assessment of a patient with a suspected eating disorder should be sufficiently complete to ensure that a thorough differential diagnosis has been considered, and no alternate cause of the symptom of concern (e.g. weight loss, vomiting) is present. Table 44-2 provides a list of conditions that may present mimicking an eating disorder.^{1,16,18,23,27-29}

The diagnostic criteria for eating disorders are published in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).^{6, 30} In assessing an individual with a suspected eating disorder, the provider must first determine the patient’s current weight, the history of weight loss (peak weight and rate of loss), and how the current weight compares with an expected body weight.

There are several methods for determining how a patient’s weight compares with an expected body weight. One method is to examine pre-illness growth curves, and to restore patients to their previous growth trajectory. If patients were always underweight, or overweight, and the clinician feels they should therefore not return to their prior trajectory, or if growth records are unavailable, the 50th percentile body mass index (BMI) for age and gender published by the Centers for Disease Control and Prevention can be a helpful starting point. This BMI is then multiplied by the current height to calculate a median body weight.³¹ However, it is understood that this is a rough reference point, as body weight is very individualized, and not everyone will need to achieve exactly the median BMI-for-age. In addition, if a patient has had significant linear growth stunting, it may be necessary to calculate a goal weight using the projected height that the patient should have achieved had she continued along a pre-eating disorder growth trajectory, in order to catch up missed linear growth.^32,33 Because of this, current guidelines recommend determining treatment goal weights while carefully incorporating patients’ individual pre-illness growth and pubertal trajectories.³⁴

It is important to note that weight criteria should be used only as guidelines when assessing pediatric patients. An eating disorder may initially appear when a child fails to make expected gains in growth parameters. The diagnosis should also be considered within the context of normal pubertal growth and adolescent development.⁵

The evaluation of a patient with a suspected eating disorder includes a complete history and physical examination. Special attention should be paid to questions regarding dieting, body image, weight-control measures, and associated psychiatric conditions. Table 44-3 suggests pertinent questions for a patient with a suspected eating disorder,²⁷ and Table 44-1 lists the potential physical findings in a patient with an eating disorder. It is important to interview both the patient and their caregivers, as some adolescents with eating disorders can under-report their symptoms significantly. Finally, when speaking with parents, remembering to show empathy and making it clear that their child’s illness is not their fault is very helpful in working with families, as they often feel an enormous burden of guilt that their child became ill. Typically parents are helpful members of the treatment team, and should be allowed and encouraged to participate in meals and care while their child is hospitalized.⁷