Bulimia nervosa (BN) is an eating disorder characterized by recurrent and compulsive episodes of overeating (binge eating) and feelings of loss of control over food intake. Driven by a distorted sense of body image, patients with BN attempt to prevent weight gain through harmful practices such as self-induced vomiting, abuse of medications (eg, laxatives, diuretics, and "diet pills"), irregular meal intervals, and/or excessive exercise. These behaviors result in extreme food cravings that restart the binge-purge cycle. Depending on frequency and severity, there may be significant medical and psychological consequences. Cutaneous manifestations are characteristic and a strong indicator of an underlying eating disorder in patients.

Patients with BN will typically be normal to slightly overweight but have a history of large fluctuations in their body mass index (BMI) over time. The purging behaviors of BN affect nearly every organ system in the body.

This summary focuses on the mucocutaneous manifestations; the most common signs and symptoms are:

• Acne – Hormonal changes during binge episodes and periods of weight gain are linked to outbreaks of acne. There is also evidence of increased incidence of polycystic ovary syndrome (PCOS) and hyperandrogenism in BN patients, conditions also associated with acne.
• Eyes and nose – Unexplained subconjunctival hemorrhage, facial petechiae, and recurrent episodes of epistaxis without any history of nasal pathology may be signs of prolonged episodes of retching.
• Oral mucosa – Epithelial erosion from acidic vomitus and frictional trauma from self-induced vomiting result in inflammation and redness of the gingiva, palate, and throat. Atrophic glossitis, mucosal atrophy, and cheilitis (lip inflammation) may also be a sign of vitamin B group deficiency. Vitamin B1, B6, and B12 deficiencies are especially associated with decreased epithelial cell turnover. Patients may also complain of burning or painful sensations of the tongue, referred to as glossodynia.
• Dental – Acidic vomitus leads to poor dentition, including teeth discoloration, frequent dental caries, and tooth sensitivity.
• Salivary – Patients develop sialadenosis, a painless, noninflammatory enlargement of salivary glands, most noticeably the parotid, due to autonomic neuropathy from repetitive vomiting. Salivary dysfunction also leads to complaints of xerostomia (dry mouth). Some patients may develop necrotizing sialometaplasia, a self-limited ulcerative lesion on the posterior hard palate, due to salivary gland necrosis. This resolves on its own in 6-10 weeks.
• Hands – Callus formations on the dorsum of the hand, known as Russell's sign, from repetitive trauma and abrasion to the skin from inducing vomit. Nail biting of varying degrees is also common. Excessive abuse of senna-based laxatives may result in reversible clubbing of fingers.
• Hair loss – Physiological stress and abnormal food intake of BN may result in hair prematurely entering the telogen phase. This thinning or shedding of hair is referred to as telogen effluvium.
• Photosensitivity – Drug-induced phototoxicity may occur from abuse of furosemide and thiazide diuretics.

BN usually begins during adolescence or young adulthood, and women are up to 15 times more likely than men to develop BN. Risk factors include childhood obesity, early pubertal maturation, family history of eating disorders, psychiatric comorbidities (eg, mood disorders), and participation in activities that encourage losing or restricting weight, such as acting, modeling, dancing (eg, ballet), and athletics (eg, running, gymnastics, or wrestling).

Careful examination and recognition of risk factors and cutaneous signs can help make an early diagnosis of hidden eating disorders such as BN.

Patients with this disorder may have an increased risk of various general medical conditions.