B27.01 Gammaherpesviral mononucleosis with polyneuropathy

Name of the Condition

• Gammaherpesviral mononucleosis with polyneuropathy

Summary

Gammaherpesviral mononucleosis with polyneuropathy is a viral infection caused by gammaherpesviruses, most commonly Epstein-Barr virus (EBV), that involves both typical mononucleosis symptoms and peripheral nerve involvement. The condition combines the classic signs of mononucleosis—such as fever, sore throat, and lymphadenopathy—with neurological symptoms related to polyneuropathy. It primarily affects adolescents and young adults but can occur in other age groups. Management focuses on addressing both the viral infection and neurological manifestations, with outcomes varying based on the severity of nerve involvement.

Causes

Gammaherpesviral mononucleosis with polyneuropathy is caused by infection with viruses in the gammaherpesvirus family, with Epstein-Barr virus (EBV) being the most frequent cause. The virus spreads through saliva, which can occur through kissing, sharing utensils or beverages, or other close contact. The polyneuropathy component may result from direct viral invasion of peripheral nerves, immune-mediated nerve damage, or both. Less commonly, other gammaherpesviruses may cause similar symptoms with associated nerve involvement.

Risk Factors

• Adolescents and young adults, particularly those in close-contact environments like college dormitories.
• Exposure to EBV, especially in settings with frequent interpersonal contact.
• Weakened immune system due to conditions like HIV/AIDS or immunosuppressive therapy.
• History of prior viral infections or autoimmune conditions that may predispose to nerve involvement.

Symptoms

• Persistent fatigue
• Fever
• Sore throat, often severe
• Swollen lymph nodes in the neck and armpits
• Numbness, tingling, or weakness in the extremities (polyneuropathy)
• Muscle weakness or pain
• Difficulty with coordination or balance
• Enlarged spleen or liver (in some cases)
• Rash (less common)

Diagnosis

Diagnosis typically involves a combination of clinical evaluation, laboratory testing, and neurological assessment. A physical exam may reveal swollen lymph nodes, sore throat, and signs of nerve dysfunction. Laboratory tests, such as a complete blood count (CBC) and EBV serology, help confirm the viral infection. Nerve conduction studies or electromyography (EMG) may be used to evaluate polyneuropathy. Imaging or additional tests may be ordered to rule out other causes of neurological symptoms.

Treatment Options

Treatment focuses on managing symptoms and addressing the underlying viral infection. Supportive care includes rest, hydration, and over-the-counter pain relievers for fever and sore throat. Antiviral medications may be considered in severe cases, though their role in gammaherpesviral infections is limited. For polyneuropathy, treatments may include pain management, physical therapy, or medications to address nerve-related symptoms. Corticosteroids or other immunosuppressants might be used if an autoimmune component is suspected.

Prognosis and Follow-Up

Most individuals recover fully with appropriate care, though recovery from polyneuropathy can be gradual and may take weeks to months. Follow-up is important to monitor for resolution of symptoms and to assess nerve function. In some cases, residual neurological symptoms may persist, requiring ongoing management. Regular check-ups help ensure complications are identified and addressed promptly.

Complications

• Persistent or chronic polyneuropathy
• Severe fatigue lasting beyond the acute infection
• Enlarged spleen (splenomegaly) with risk of rupture
• Liver inflammation (hepatitis)
• Rarely, more serious neurological complications like Guillain-Barré syndrome

Lifestyle & Prevention

• Practice good hygiene, such as avoiding sharing utensils or beverages.
• Limit close contact with individuals showing symptoms of mononucleosis.
• Get adequate rest during acute illness to support recovery.
• Maintain a balanced diet and hydration to aid immune function.
• Avoid activities that strain the body or increase injury risk, especially if the spleen is enlarged.

When to Seek Professional Help

Seek medical attention if you experience:

• Severe or worsening neurological symptoms, such as sudden weakness or numbness.
• High fever that does not improve with treatment.
• Difficulty breathing or swallowing.
• Abdominal pain (possible spleen enlargement).
• Symptoms that persist beyond a few weeks without improvement.

Tips for Medical Coders

When coding for gammaherpesviral mononucleosis with polyneuropathy, use ICD-10-CM code B27.01. Ensure documentation clearly links the mononucleosis diagnosis to the presence of polyneuropathy, including details on symptom onset, duration, and any neurological findings. Code assignment should reflect the combination of the viral infection and the specific neurological complication. Review clinical notes for confirmation of both components to support accurate coding.