Bell’s Palsy and the Pharmacist

US Pharm. 2019;(1):26-30.

ABSTRACT: Bell’s palsy is an uncommon neurologic disorder of uncertain etiology that causes numerous problems for patients. Symptoms usually remit completely in a short period of time, but they can be permanent. The hallmark symptom is hemifacial paralysis, causing facial deformity and disrupting speech. Drooping eyelids and impaired blinking result in dry eye. Patients also suffer dry mouth and inability to clear masticated foods from the oral cavity. Patient response to oral steroids and antivirals is variable. Pharmacist assistance in self-care includes recommending products for dry eye, dry mouth, oral cleansing, cheek injuries, and minor pains.

Bell’s palsy is an acute-onset, unilateral facial nerve weakness or paralysis without a definite cause.^1,2 This condition was named after Sir Charles Bell, a Scottish anatomist, who described multiple cases of facial nerve paralysis in the early 1800s.^2,3 It is the most common disorder affecting the facial nerve and is responsible for approximately 80% of all facial mononeuropathies.³

Incidence and Epidemiology

Bell’s palsy affects 11 to 40 persons per 100,000 worldwide, with 40,000 to 60,000 new cases diagnosed each year in the United States alone.^3-5 Peak incidence occurs between the ages of 15 and 50 years, although it can occur at any age. New cases are more frequently diagnosed in the spring and fall than at other times of the year.^4,6 The reasons for seasonal variations in onset remain unknown. Similar rates are seen between genders and among different ethnicities.^3,7 Pregnant women have been shown to have a higher incidence, with up to a three times greater risk than the general population.^3,8 Other susceptible groups include patients with recent respiratory tract infections, diabetes, hypothyroidism, or immunocompromise.^3,4,7 The reasons behind the apparent associations between Bell’s and these conditions (e.g., hypothyroidism) are not proven, although the hypothesized role of infectious agents may underlie the observed predilection for patients with respiratory infections and immunocompromised status. The link to diabetes may indicate that those patients suffer subclinical damage to the facial nerve that may eventually manifest as symptomatic Bell’s.⁴

Etiology

Although the definitive cause of Bell’s palsy remains unclear, current literature indicates the likely involvement of latent herpes viral infection and subsequent migration to the facial nerve. Herpes simplex virus-1 (HSV-1) and herpes zoster virus may be causative agents, but HSV-1 seems to be the more frequent cause.^3,9,10 Other infectious disease-related etiologies include cytomegalovirus, Epstein-Barr virus, adenovirus, rubella virus, mumps, influenza B, and the coxsackie virus.^3,11 Familial occurrence has also been documented, with 4% to 8% of Bell’s palsy patients reporting a family history. Alternative theories related to vascular ischemia and autoimmune disease have also been advanced.³

Symptoms and Complications

Numerous victims of Bell’s palsy report that a prodrome of pain, dull aching, or discomfort behind the ear precedes the full spectrum of symptoms.^12,13 Symptoms begin suddenly, often in the morning, and reach a peak in 48 hours.¹⁴ When symptoms begin, they can range in severity from mild to severe, although this varies considerably from person to person.^12,14 Most patients experience improvement within a few weeks, with complete recovery in 3 to 6 months. For some patients, symptoms last for a year or more, and a few patients have permanent disfigurement. The seemingly unrelated set of symptoms reflects the broad range of functions for which the seventh cranial (facial) nerve is responsible.

Facial Paralysis and Asymmetry: The hallmark symptom of Bell’s palsy is hemifacial paralysis, ranging from mild weakness to complete immobility (only rarely are both sides of the face affected).^14-16 In the more severe variants, profound facial flaccidity causes complete loss of normal facial aspects such as the forehead frown lines, the nasolabial fold, and smile lines around the mouth, all limited to the affected (ipsilateral) side.¹³ Facial paralysis may be so severe that the patient is completely unable to move the musculature with normal mental commands.

The patient most often notices onset of the paralysis early in the morning, shortly after awakening. Many patients are aware that sudden paralysis of any part of the body is characteristic of a stroke. Some visit an emergency room for diagnosis and treatment. When an examination demonstrates that the arms, legs, hands, and feet are not affected, the diagnosis points to Bell’s palsy, which can be further confirmed with an MRI.

Ophthalmic Involvement: Loss of control of the muscles of the ipsilateral eyelids (both lower and upper) causes them to fall into an unnaturally lowered position, enhancing the facial asymmetry.¹⁷ The upper eyelid develops ptosis, a noticeable droop, while the lower eyelid sags outward/away from the eye, a condition known as ectropion.¹⁵ The patient can neither completely close the eye nor blink. Blinking carries tears upward to cover the surface of the eye, and also allows tears to drain into the tear ducts.¹⁸ Inability to blink causes tears to accumulate in the sagging lower eyelid. The patient notices a watery eye from which accumulated tears leak out to run down the cheek.¹⁵ Loss of tears in this manner along with tear evaporation due to inability to blink or completely close the eyelid results in dry eye (xerophthalmia).¹⁹ Dry eye is one of the condition’s most dangerous symptoms.¹⁴ Tears are critical in washing particles from the eye.¹⁹ Retained particles can cause irritation, burning, itching, and/or redness. Dry eye can also cause blurred vision, a gritty or scratchy sensation, and light sensitivity.^19-21 If it persists, it can lead to extremely painful corneal ulceration and/or scarring, which can cause visual impairment or irreversible visual loss.^22,23

Oral Complications: Loss of ability to control the muscles of the mouth and cheek is also problematic. Half of the lip sags, deviating the angle of the mouth into an uneven slant, so that the patient is unable to pucker the lips.¹³ This leads to speech problems and an inability to eat without solid or liquid food falling out.¹² The patient complains of drooling while eating, loss of fluid while using mouthwash, and inability to use a straw, whistle, or smoke cigarettes.²⁴ The cheek and its accompanying musculature are immobile. Therefore, food that the cheek would normally move around the intraoral cavity during mastication is trapped in the upper and lower buccal pouches.²⁴ The salivary glands are also partially controlled by the seventh cranial nerve, and its dysfunction results in dry mouth (xerostomia) and also contributes to intraoral food retention following a meal.²⁵ Longstanding xerostomia and retained food particles can lead to plaque, caries, gingival disease, periodontitis, and tooth loss. A related issue arises from laxity of the cheek and lip muscles. As the patient chews, the affected cheek tends to sag inwards, so that it can be caught between the chewing surfaces of the jaws during mastication. Similarly, the lip can be accidentally bitten as the patient chews. Once bitten, the tissues are inflamed, which causes them to protrude even further, increasing the risk of reinjury. Fortunately, the ability to swallow food is seldom affected by Bell’s.

Pain: Bell’s palsy can cause pain in several locations.¹⁸ These include headache, pain around the jaw and behind or in the ear, and the prodromal pain mentioned above.^14,16

Additional Problems: Bell’s can also cause twitching of the facial muscles, facial numbness or tingling, and dysgeusia on the anterior ipsilateral portion of the tongue. Otic involvement may include tinnitus, deafness, or sounds being louder (hyperacusis).^12,16,26 These are usually confined to the ipsilateral ear but may affect both. Some patients are also bothered by dizziness and inability to maintain normal balance. The triad of deafness, tinnitus, and vertigo leads to confusion of Bell’s palsy with Meniere syndrome. However, Meniere does not produce the hemifacial paralysis that is characteristic of Bell’s palsy. 

Prescription Interventions

Many patients with Bell’s do not require treatment because the condition often begins to improve rapidly after onset.¹² Given the unclear etiology, there currently is no method available to prevent or cure Bell’s palsy. Furthermore, the degree to which pharmacologic agents improve the condition is unknown. Nevertheless, corticosteroids are often prescribed in the hope that they will decrease inflammation of the facial nerve, improve function, and decrease recovery time.^4,12,27 Current guidelines recommend that new cases of Bell’s palsy in patients over age 16 years be prescribed oral corticosteroids within 72 hours of symptom onset. One regimen is prednisolone 50 mg daily for 10 days. Another is prednisone 60 mg daily for 5 days, subsequently reducing the dose by 10 mg each day for the next 5 days.^2,28 Potential side effects of these medications include gastrointestinal upset, peripheral edema, mood changes, hypertension, and elevated blood glucose levels.²

Antiviral medications with activity against herpes simplex virus have also been used in some patients, with mixed results.²⁹ Current guidelines recommend against the use of antivirals as monotherapy. However, there may be a small benefit in adding antiviral agents to corticosteroids in patients with severe facial palsy.^2,28 Acyclovir is prescribed, but valacyclovir may be preferred because of its improved bioavailability and less complicated and shorter dosing regimen. The optimal doses and regimens are not clear, but valacyclovir 1 g three times daily and acyclovir 400 mg five times daily are commonly administered in studies. Both antivirals are typically well tolerated, with gastrointestinal issues such as nausea, vomiting, and diarrhea being the most common adverse effects.²

The Role of the Pharmacist in Self-Care

Dry Eye: Self-care for dry eye of Bell’s palsy requires more care than dry eye due to other causes, because the typical Bell’s patient cannot completely close the affected eye, as described above. For daytime treatment of dry eye, the pharmacist has numerous choices of eye drops and gels. Safe and effective FDA-approved ingredients include celluloses, polyvinyl alcohol, glycerin, etc.³⁰ Products containing them include Refresh, GenTeal, Visine Dry Eye Relief, and Systane. Patients should instill 1-2 drops in the eye as needed during waking hours.

 Treatment of dry eye during the night is the great challenge for Bell’s palsy patients, owing to an inability to completely close the eye during sleep. The patient should be advised to apply liberal amounts of a mineral oil/white petrolatum ointment into the lower eyelid prior to bedtime. Examples of these products include Soothe Night Time, Refresh P.M., and Refresh Lacri-Lube. The patient should then use one hand to gently and completely pull the upper eyelid down to meet the lower eyelid.¹² The patient should then apply a strip of hypoallergenic paper tape to the junction line between the lids, ensuring that the lids do not open during sleep.³¹ It would be helpful to use two to three additional strips in an “X” pattern over the first strip of tape at the eyelid junction. If the eye is not taped shut, it will dry despite application of ointment. When selecting a dry eye drop, patients should be advised to avoid Rohto, as it contains menthol, which can irritate the eye.³² Similasan for dry eyes is homeopathic, and also should be avoided, as it is not known to be either safe or effective for dry eye.³³

Dry Mouth: Counseling patients regarding treatment of dry mouth is simpler than dry eye. Products available were not reviewed by the FDA, but seem to be effective. They include Salivart, Biotene, and MouthKote. Patients can be advised to use them liberally, as often as needed.³⁴

Cheek Injuries: An accidental bite of the cheek is a painful intraoral wound.³⁵ In some patients, the injury can also develop into an even more painful canker sore, which takes 10 to 14 days to heal. Pharmacists can advise patients with either type of intraoral wound to use two groups of products. The first is intended to cleanse the wound. These products contain carbamide peroxide (e.g., Gly-Oxide) or hydrogen peroxide (e.g., Peroxyl). The second group of products contains benzocaine and/or menthol to relieve the pain and discomfort of the wound. Products with 20% benzocaine include Orabase, Benzodent, Orajel for Mouth Sores, and Kank-A. Zilactin-B and Anbesol Regular contain 10% benzocaine. Orajel for All Mouth Sores Antiseptic Rinse contains 0.1% menthol and hydrogen peroxide.

Oral Hygiene: Inability to clear the buccal pouches of food facilitates growth of the oral microbiota. As time passes, a film of plaque covers tooth surfaces. Eventually, it develops into a solid material known as plaque or tartar. Plaque is responsible for caries and gingivitis, and it can lead to periodontal disease and tooth loss. Xerostomia also increases the risk of caries, since saliva raises the oral pH, reducing acidic degradation of dental enamel. For these reasons, it is critical for the Bell’s palsy patient to institute a strict regimen of oral care. Following each meal or snack, the patient must dislodge food particles from crevices by rinsing thoroughly. A Water-Pik or similar device can also help. The patient should remove any plaque by brushing carefully, perhaps using a sonic-powered toothbrush such as SoniCare. Patients should floss once daily and consider the use of a fluoride-containing rinse once daily, using a product such as ACT Rinse, Phos-Flur, or Listerine Fluoride Defense. A dentist or periodontist may also recommend a periodontal cleaning device such as Proxabrush.

Pain: The pain of Bell’s palsy is usually not severe, sharp, or stabbing. The pharmacist can recommend nonprescription internal analgesics such as acetaminophen, ibuprofen, or naproxen. Each ingredient’s label carries numerous instructions necessary for safe use, as well as vital warnings and contraindications.

Conclusion

Patients with Bell’s palsy undergo significant bodily changes as the condition develops and worsens. Informed pharmacists can provide assistance on several fronts. Chief among these is proper care of the eye, but pharmacists can also help patients select products and devices for dry mouth, cheek bites, oral hygiene, and various pains.

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