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Salem Health: Infectious Diseases & Conditions, 2nd Edition

Bell’s palsy

by Patricia Stanfill Edens, , R.N., Ph.D., FACHE

Category: Diseases and conditions

Anatomy or system affected: Central nervous system, head, mouth, muscles

Also known as: Facial palsy, idiopathic peripheral facial palsy

Definition

Bell’s palsy occurs when the seventh cranial nerve that controls muscles in the face swells or becomes inflamed. One side of the face may droop, causing a crooked smile. The eye on the affected side may not close, and normal facial movements are difficult. Tears, taste, and saliva may also be affected, as may a bone in the middle ear. Bell’s palsy is temporary and usually goes away in three to six months. In some people, prolonged facial drooping may occur or a second episode may develop.

Causes

Viral infections are the primary cause of Bell’s palsy. The herpes simplex virus associated with genital herpes and cold sores is the primary cause, but other viruses can also lead to problems. These viruses include herpes zoster, which causes chickenpox and shingles; Epstein-Barr virus, which causes mononucleosis; and cytomegalovirus.

Risk Factors

Bell’s palsy is seen in the latter stages of pregnancy or soon after birth in women, in people with respiratory infections or influenza, and in people with diabetes. There may be a genetic tendency for Bell’s palsy, and episodes may be seen among family members.

Symptoms

A sudden onset of drooping on one side of the face is the most common symptom of Bell’s palsy, but in rare cases drooping may occur on both sides of the face. Jaw pain and ear pain on the affected side often occurs. Headache and sensitivity to noise, changes in the taste of food or drink, and noticeable changes in saliva and tears may also be seen.

Screening and Diagnosis

There is no screening test for Bell’s palsy. Diagnosis is made by evaluating symptoms and taking a careful history to determine if there has been a recent viral infection. Because the symptoms of Bell’s palsy may resemble stroke, tumors, Lyme disease, and other infections, a doctor may order a computed tomography scan, magnetic resonance imaging, or electromyography, which measures nerve impulses to the muscle.

Treatment and Therapy

There are some treatments for Bell’s palsy that may cause symptoms to subside more rapidly, but recovery usually occurs with or without treatment. Antiviral medicines such as acyclovir or valcyclovir may be used if the cause is linked to a viral infection. Steroids may be used alone, or in combination with an antiviral drug, to decrease inflammation of the nerve. In rare cases, surgery may be used to widen the bony corridor where the nerve passes through to the face. Physical therapy may be ordered by the doctor to keep the facial muscles in shape during the disease. The patient is taught how to exercise and massage the facial area.

Because the affected eye may not close completely, lubricating drops or ointments and eye protection may be used. Moist wet heat applied to the face may ease discomfort. Medications for pain may be prescribed.

Prevention and Outcomes

There is no single known cause for Bell’s palsy, so the best prevention is to avoid infection. Helpful preventive measures are careful handwashing, avoiding contact with sick people, and practicing safer sex.

Further Reading

1 

Bradley, Walter G., et al., eds. Neurology in Clinical Practice. 5th ed. Philadelphia: Butterworth Heinemann/Elsevier, 2007.

2 

Hazin, R., B. Azizzadeh, and M. T. Bhatti. “Medical and Surgical Management of Facial Nerve Palsy.” Current Opinion in Ophthalmology 20, no. 6 (November, 2009): 440-450.

3 

Parker, James N., and Philip M. Parker, eds. The Official Patient’s Sourcebook on Bell’s Palsy. San Diego, Calif.: Icon Health, 2002.

4 

Woodson, Gayle E. Ear, Nose, and Throat Disorders in Primary Care. Philadelphia: W. B. Saunders, 2001.

Web Sites of Interest

All Bell’s Palsy

http://allbellspalsy.info

National Institute of Neurological Disorders and Stroke

http://www.ninds.nih.gov

See also: Acute cerebellar ataxia; Autoimmune disorders; Bacterial endocarditis; Creutzfeldt-Jakob disease; Endocarditis; Gerstmann-Strôussler-Scheinker syndrome; Guillain-Barré syndrome; Herpes simplex infection; Inflammation; Meningococcal meningitis; Myocarditis; Pericarditis; Pregnancy and infectious disease; Rheumatic fever; Tetanus; Viral infections.

Citation Types

Type
Format
MLA 9th
Edens, Patricia Stanfill. "Bell’s Palsy." Salem Health: Infectious Diseases & Conditions, 2nd Edition, edited by H. Bradford Hawley, Salem Press, 2020. Salem Online, online.salempress.com/articleDetails.do?articleName=Infect2e_0067.
APA 7th
Edens, P. S. (2020). Bell’s palsy. In H. B. Hawley (Ed.), Salem Health: Infectious Diseases & Conditions, 2nd Edition. Salem Press. online.salempress.com.
CMOS 17th
Edens, Patricia Stanfill. "Bell’s Palsy." Edited by H. Bradford Hawley. Salem Health: Infectious Diseases & Conditions, 2nd Edition. Hackensack: Salem Press, 2020. Accessed December 14, 2025. online.salempress.com.