02-07-2025
Think Beyond Stroke in Sudden Facial Droop
Infectious mononucleosis (IM), also known as the kissing disease or 'mono,' is typically caused by the Epstein-Barr virus (EBV). It is a clinical condition characterised by fever, lymphadenopathy, and pharyngitis.
Bell's palsy is a condition that causes sudden, temporary facial paralysis or weakness on one side of the face. It can have various aetiologies, such as congenital, neurologic, infectious, neoplastic, or traumatic.
This report describes the case of a woman who was diagnosed with Bell's palsy, a rare neurologic complication of EBV-associated IM.
The Patient and Her History
An 18-year-old woman with a medical history of low back pain and sinusitis presented to the clinic with complaints of fever, sore throat, and left-sided facial drooping. She reported noticing these symptoms 1 week prior. The neck pain had progressively worsened and radiated to the left ear. The patient also experienced difficulty forming words and was unable to raise her left eyebrow or smile due to facial drooping. She noted no improvement with over-the-counter medications and denied recent travel.
Findings and Diagnosis
On physical examination, several 1-cm mobile tender anterior cervical lymph nodes were noted. Tonsillitis with white exudates and left ear tympanosclerosis with associated pain were observed. The left corner of the mouth was drooping, and the patient had difficulty making facial expressions and closing her left eye. The spleen was palpable and tender to touch. Neurologic examination showed that all other cranial nerves were grossly intact. The muscle strength was 5/5 in both the upper and lower extremities, and deep tendon reflexes were present throughout. The lungs were clear to auscultation, and pulses were palpable in all extremities. No oedema, cyanosis, or clubbing was observed. The skin was dry, and no rashes were observed.
Laboratory tests showed mild leucocytosis. Rapid antigen tests for streptococci, influenza, and COVID were negative. A rapid heterophile antibody test for EBV was positive.
The mononucleosis spot test was positive for reactive heterophile antibodies, a hallmark finding of IM. Immunofluorescence assays showed positive immunoglobulin M and immunoglobulin G antibodies against EBV, with the presence of immunoglobulin M antibodies indicating either a recent primary infection or a reactivated infection.
On the basis of these findings, a diagnosis of left-sided Bell's palsy due to EBV infection was confirmed. The patient was prescribed prednisone 60 mg for 1 week, with a plan to taper the dose. Tylenol was recommended for pain management as needed.
Artificial tears were prescribed to prevent corneal damage and dryness due to the inability to close the left eye. An ear, nose, and throat (ENT) referral was made for the evaluation of left ear tympanosclerosis and associated pain. The patient was counselled to avoid contact sports because of the risk for splenic rupture, a common complication of IM.
At the 2-week follow-up, the patient reported symptoms such as runny nose, fatigue, and ongoing ear pain, pending evaluation by an ENT specialist. At that time, there was no evidence of lymphadenopathy, fever, or splenomegaly. The patient's facial paralysis had improved by approximately 70%, and her speech was also markedly improved. The patient was counselled to rest, stay hydrated, and closely monitor for new symptoms.
Discussion
IM, most often caused by the EBV, is a viral illness that primarily affects teenagers and young adults. It is transmitted through saliva — which is why it is often referred to as the 'kissing disease' — but can also be spread via respiratory droplets, blood, or organ transplants. Symptoms may include sore throat, fever, swollen lymph nodes, and extreme fatigue, as well as swelling of the liver and spleen. A heterophile antibody test is typically sufficient to diagnose IM. Most people recover on their own with rest, fluids, and over-the-counter pain relievers. However, in rare cases, complications such as a ruptured spleen, neurologic issues, or liver inflammation can occur.
Neurologic complications, such as cranial nerve palsies, Guillain-Barré syndrome, meningoencephalitis, and mononeuritis multiplex, occur in approximately 1%-5% of all patients with acute EBV infection. In children, neurologic manifestations may be the only clinical sign that can occasionally delay diagnosis.
Acute peripheral facial paralysis is the most common acute mononeuropathy and often presents a diagnostic challenge for physicians. Its incidence has been reported as 21.1 per 100,000 per year in children younger than 15 years. Paediatric facial nerve paralysis can be congenital or acquired, but the idiopathic form, known as Bell's palsy, is the most frequent, accounting for 40%-75% of cases.
Bell's palsy is diagnosed by the abrupt onset of unilateral facial weakness or complete paralysis of all muscles on one side of the face. It may be accompanied by dry eyes, pain around the ear, an altered sense of taste, hypersensitivity to sounds, or decreased tearing.
Recovery time varies, but complete resolution of symptoms usually occurs within 2-3 weeks.
There is always a small possibility of permanent functional loss, which can result from structural damage to axons and myelin. Treatment is usually supportive, often involving a combination of steroids and, in some cases, physical therapy. Facial nerve palsy is most often idiopathic and related to microcirculatory changes but may also result from congenital defects, infections, trauma, neoplasms, or systemic illness. Infectious causes account for 5%-30% of cases and are the most common cause in young children. Common pathogens include herpes simplex virus 1, varicella-zoster virus, EBV, Borrelia burgdorferi , HIV, and influenza virus. The causes of facial palsy are classified as follows:
Genetic: Hereditary myopathies, gene mutations
Syndromic: Craniofacial malformations and brainstem disorders
Delivery-related: Prematurity, instrumental delivery, caesarean section
Infectious: Viral, bacterial, and fungal agents including chronic or acute otitis media
Inflammatory: Autoimmune and vasculitis conditions
Neoplastic: Tumours involving the facial nerve or surrounding structures
Traumatic: Skull fractures affecting the facial nerve
Iatrogenic: Injury during head and neck surgeries
Idiopathic: Bell's palsy
Timely diagnosis and stroke exclusion are critical to avoid permanent damage. Lyme disease should be ruled out, especially in patients with recent travel to endemic areas and a bull's eye rash.
