Why Does Bulimia Cause Swelling & “Chipmunk Cheeks”?

Bulimia Nervosa & Chipmunk Cheeks

There are many words for it: “chipmunk cheeks,” “bulimia cheeks,” or “bulimia face.” It’s a ubiquitous, and often embarrassing, marker of an eating disorder. The swelling of the face experienced in this setting is common, but can often be a source of anxiety and shame for patients. Why does it happen?

Purging and Non-Purging Behaviors

Compensatory behaviors are purging or non-purging behaviors with the intent to compensate for food intake and prevent weight gain.¹Purging behaviors involve elimination in order to compensate for food intake. Purging behaviors include laxative misuse, diuretic misuse, enemas and the most common form of purging, self-induced vomiting. Non-purging behaviors include any type of compensatory behavior that does not involve purging, which may include food restriction, excessive exercise or diet pills.^2,3,4

The Impact of Self-Induced Vomiting

Self-induced vomiting can cause a myriad of different medical complications, affecting the mouth, lips, esophagus and teeth. Some other related complications are gingivitis, periodontal disease, enamel erosion, tooth damage, chronic dry mouth and bad breath.

Identifying Bulimia Nervosa

Chipmunk cheeks are often associated with bulimia nervosa. Bulimia nervosa (BN) is an eating disorder characterized by cyclical episodes of binge eating and compensatory behavior. A binge eating episode is characterized by eating an amount of food in a discreet period of time that is definitively larger than what most individuals would eat in a similar amount of time under similar circumstances while also feeling that one cannot stop eating or control what or how much they are eating. Binge eating and compensatory behaviors occur, on average, at least once a week for 3 months.¹

Purging in Other Eating Disorders

While chipmunk cheeks are closely associated with bulimia nervosa, it can occur in any patient that has a purging eating disorder, like those with anorexia nervosa binge eating/purging subtype (AN-BP) or those with other specified feeding or eating disorder (OSFED), like purging disorder.

Anorexia Nervosa Binge Eating/Purging Subtype

Anorexia nervosa is divided into two subtypes: restricting type (AN-R) and AN-BP. AN-BP shares the same diagnostic criteria as AN-R, and also includes regular engagement in binge-eating or purging within the last 3 months instead of or alongside restricting behaviors.¹

Purging Disorder

Unlike bulimia nervosa and AN-BP, purging disorder is not an independent diagnosis, but instead a descriptor of those with OSFED engage in purging behaviors like self-induced vomiting or laxative and diuretic misuse, without experiencing eating binges or being underweight.¹

“Chipmunk Cheeks”: A Common Sign of Purging

“Chipmunk cheeks” are one of the telltale signs an individual has been purging via self-induced vomiting. Chipmunk cheeks – medically known as acute sialadenosis – is caused by the enlargement of the salivary glands. Sialadenosis consists of puffy, swollen or otherwise enlarged salivary glands in the face, giving a bloated appearance to the sides of the face. Between 10-50% of patients with self-induced vomiting report sialadenosis.⁵

For people struggling with an eating disorder, sialadenosis can feel especially triggering, but the appearance of swollen salivary glands are a direct result of the mechanics of purging through self-induced vomiting.

Why Do the Salivary Glands Swell?

The human body contains three major salivary glands: the parotid glands, the submandibular glands and the sublingual glands. In pairs of two, they are located under the ear, under the tongue and along the mandible. The salivary glands are responsible for producing saliva, which aids in digestion and other bodily functions. Sometimes, like in the case of those with eating disorders, one or more of these salivary glands can become swollen. Sialadenosis most commonly affects the parotid glands but can affect any of the salivary glands in the cheeks.¹ Sialadenosis is commonly described as a relapsing, bilateral, asymptomatic, non-inflammatory, non-neoplastic (benign) salivary gland enlargement and does not affect the gland functioning.⁶

The exact mechanism for salivary gland enlargement is unknown, but some evidence suggests peripheral autonomic neuropathy as a main factor. Peripheral autonomic neuropathy increases acinar protein production and/or an interrupted granular release. The accumulation of zymogen granules in the acinar cells causes parotid gland enlargement and impaired salivary secretion. The degenerative alteration in myoepithelial cells and postganglionic sympathetic neurons may be the cause of sialadenosis, as they control salivary synthesis and secretion.^7,8

Another hypothesis is that sialadenosis is the result of either regurgitation of acidic contents, consumption of carbohydrate dense foods over a short period of time in binge-eating episodes or the result of pancreatic proteolytic enzymes coming back into the mouth during vomiting and stimulating lingual receptors.^7,8,9

The enlargement of salivary glands may be associated with elevations ins serum amylase levels.¹ There are several studies of patients with BN evaluating salivary content. Some studies have found elevated levels of amylase in both unstimulated and stimulated salivary samples of the patients with BN, but other studies have reported an insignificant differences compared to controls. ^9,10 One study suggests that the oral changes in eating disorders result primarily due to cariogenic dietary patterns and binge eating and purging habits and not due to physiologic salivary alterations.⁷ 

Treatment for Salivary Gland Enlargement

While salivary gland enlargement is typically asymptomatic, painless and benign, the appearance of “chipmunk cheeks” can compound already existing body image disturbances in eating disorder patients. Therefore, it remains important to offer options for relief and guide patients through this phase of recovery.

Good News: “Chipmunk Cheeks” is Largely Temporary

Thankfully, salivary gland enlargement is temporary. While select cases can persist for months or years following recovery, most patients will notice their swelling subside within a couple weeks after purging stops. Unfortunately, they do not shrink immediately, so it’s important to emphasize patience.

If patients are experiencing pain or discomfort over the counter pain relievers, such as ibuprofen or acetaminophen, can help. Applying heating pads to the area can also provide some relief. Sialagogues (lemon drops or other tart candies) can also be used to alleviate symptoms by stimulating saliva production.

In persistent cases, a medication called pilocarpine may be used to reduce the size of the salivary glands,11 but patients should be monitored for serious side effects that may affect their recovery, like diarrhea, vomiting, tachycardia (elevated heart rate), bradycardia (low heart rate) or irregular heartbeat.

In extremely rare occasions, surgical procedure called a parotidectomy (partial or complete removal of the parotid gland) may be necessary to slim the face.

References

1. American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Washington, DC: APA.

2. Abebe, D. S., Lien, L., Torgersen, L., & Von Soest, T. (2012). Binge eating, purging and non-purging compensatory behaviours decrease from adolescence to adulthood: A population-based, longitudinal study. BMC Public Health, 12(1). https://doi.org/10.1186/1471-2458-12-32
3. Nitsch, A., Dlugosz, H., Gibson, D., & Mehler, P. S. (2021). Medical complications of bulimia nervosa. Cleveland Clinic Journal of Medicine, 88(6), 333–343. https://doi.org/10.3949/ccjm.88a.20168
4. Mehler, P. S., & Andersen, A. E. (2017, November 29). Eating Disorders: A Guide to Medical Care and Complications (third edition). Johns Hopkins University Press.
5. Mehler PS. Medical complications of bulimia nervosa and their treatments. Int J Eat Disord. 2011;44:95–104.
6. Arya S, Pilania A, Kumar J, Talnia S. Diagnosis of bilateral parotid enlargement (Sialosis) by sonography: A case report and literature review. J Indian Acad Oral Med Radiol. 2019;31:79–83.
7. Donath K, Seifert G. Ultrastructural studies of the parotid glands in sialadenosis. Virchows Arch A Pathol Anat Histol. 1975;365:119–35.
8. Coleman H, Altini M, Nayler S, Richards A. Sialadenosis: A presenting sign in bulimia. Head Neck. 1998;20:758–62.
9. Riad M, Barton JR, Wilson JA, Freeman CP, Maran AG. Parotid salivary secretory pattern in bulimia nervosa. Acta Otolaryngol. 1991;111:392–5
10. Tylenda CA, Roberts MW, Elin RJ, Li SH, Altemus M. Bulimia nervosa. Its effect on salivary chemistry. J Am Dent Assoc. 1991;122:37–41.
11. Mehler, P. S., & Wallace, J. A. (1993). Sialadenosis in bulimia: a new treatment. Archives of Otolaryngology-head & Neck Surgery, 119(7), 787–788. https://doi.org/10.1001/archotol.1993.01880190083017

Last Reviewed: June 2023 by Dennis Gibson, MD, FACP, CEDS