Approach
Patients with bulimia nervosa are often ashamed to admit they have the disease. Therefore, a high index of suspicion is important. Patients may present with symptoms related to bulimia, such as menstrual irregularity, fluctuations in weight, rapid onset of tooth erosion, or changes in mood. Alternatively, some will complain of a single issue, such as heartburn or swelling of the sides of the face, denying further symptoms at first.
Initial evaluation
The disease most commonly occurs in women aged 20 to 35 years. It is much less common in men. Unlike women, men usually want to gain weight in the form of muscle, but lose fat. Other factors in the history that would increase suspicion for a possible diagnosis of bulimia nervosa include:
perfectionism, body dissatisfaction, impulsivity
history of dieting
marked shifts in weight
history of depression and low self-esteem.
On specific questioning, patients may express concerns over their weight and shape, although this may be denied initially.
Physicians should be aware that abuse of laxatives and drug-seeking behavior for laxatives and appetite suppressants are common. Shoplifting may also be noted. Medications may be collected to use for suicide. In addition, the emetic ipecac is used by some patients to induce vomiting. Cardiomyopathy is rare in bulimia, but ipecac abuse use may lead to a cardiomyopathy. Other complications of bulimia that may present include cardiac arrhythmias, most commonly secondary to hypokalemia and hypomagnesemia, and pancreatitis.
Physical exam may be normal. There may be evidence of parotid hypertrophy, dental erosion, and scarring over the dorsum of the hands. The scars are a result of pressure from the teeth against the hand following insertion into the mouth to induce vomiting (Russell sign).[62][63][64][65] Patients are unlikely to reveal self-injurious behavior. Examination of the skin may reveal evidence of self-harm.[66] Puncture marks are uncommon, but may be present as evidence of self-phlebotomy (form of purging).
Features of serious complications
Suicide
When patients are being assessed for the risk of death from suicide, they should be questioned about hoarding of medications.
Arrhythmias
Arrhythmias are sensed by some patients, and those associated with loss of consciousness, syncope, or seizures require immediate evaluation.
Hematemesis
Usually not significant if it involves the vomiting of a total blood volume of <15 mL. Even larger volumes are usually due to a Mallory-Weiss tear, which typically requires no intervention. However, any patient who vomits >15 mL of blood should be evaluated in the emergency room.
Confirming the diagnosis
To confirm the diagnosis of bulimia nervosa, it is necessary to take a more detailed history using criteria such as those of the DSM-5-TR.[1]
DSM-5-TR criteria require the episodes of binge eating to have the following characteristics:
Eating must be in a discrete period of time and must be of an amount of food that is definitely larger than most people would eat during a similar period of time and under similar circumstances.
There must be a sense of lack of control over the eating during the episode.
The following factors are also considered part of DSM-5-TR criteria:
There is recurrent inappropriate compensatory behavior to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, enemas, or other medications; fasting; and excessive exercise.
Binge eating and inappropriate compensatory behaviors both occur at least once a week for 3 months, on average.
Self-evaluation is unduly influenced by body shape and weight.
The disturbance does not occur exclusively during episodes of anorexia nervosa.
Common pitfalls in history-taking are to:[67]
Underestimate the likelihood of errors in history due to shame and depression.
Describe the components of the history in terms that the patient misunderstands. For example, the patient is unlikely to understand the term "purge". Therefore, the following questions in this regard would be more appropriate:
Do you ever vomit or bring food up?
Does this happen after you eat?
Do you make the food come up?
How do you cause the food to come up?
Other simple questions that help to establish the diagnosis and avoid confusion include:
Do you ever eat a lot more than usual?
Please give me an example of how much you might eat. Could it be twice as much as you normally eat or 5 times as much, or 10 times as much?
Record the objective features of binge eating and purging without including the impact of the behaviors on mood and quality of life.
Concentrate on only the very recent history.
Laboratory testing
No laboratory investigations confirm the diagnosis. Laboratory tests screen for complications and establish baseline values. These include complete blood count, sodium, potassium, chloride, bicarbonate, aspartate aminotransferase, alkaline phosphatase, magnesium, phosphorus, B12, red blood cell folate, ferritin, urinalysis, pregnancy test, and electrocardiogram. Dual-energy x-ray absorptiometry bone density measurement is not routine, but can be requested if there is a suspicion of bone loss, for example, in the case of irregular menses.
Patients with diabetes
Patients with comorbid diabetes mellitus may have poor glycemic control. Some patients may skip insulin to control their weight.[4] This leads to marked fluctuations in blood sugar and a rapid onset of diabetic microvascular complications.
Pregnancy
Bulimia nervosa improves with pregnancy in about two-thirds of cases and worsens in about one third. Usually the diagnosis of bulimia nervosa is known before pregnancy. If this is the case, the patient often reports trying to get pregnant beforehand and asks how to prepare. Medications that should not be taken during pregnancy should be stopped before conception.[68]
Laboratory tests should be monitored to ensure that there are no deficiencies requiring correction. Vitamin intake and exercise should be discussed. If the patient is not known to have bulimia nervosa, the presentation may be mistaken for hyperemesis gravidarum. The presence of urinary ketones or hypokalemia, or fluctuations in weight, may be confusing. Clinicians should therefore be alert to the diagnosis.
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