Mononucleosis- Causes, Symptoms, Diagnosis, Treatment and Ongoing care

Basics

Description

Infectious mononucleosis (IM) is an acute illness owing to Epstein-Barr virus (EBV) infection that occurs mainly in adolescents and young adults.

Epidemiology

Incidence

Not a reportable disease, but by age 5 years, approximately half of all Americans have been infected; 90% by age 25 years.IM accounts for fewer than 2% of pharyngitis cases in adults. The vast majority of adults are not susceptible to infection because of prior exposure.The incidence is approximately 30× higher in whites than in blacks in the US.No seasonal peak

Prevalence

Approximately 50% of people who are infected with the virus will develop symptoms; others can carry the virus, not knowing they have it.

Risk Factors

Age between 10 and 30 yearsPopulations with many young adults, such as active-duty military personnel, high school and college students

Genetics

Unknown

General Prevention

No blood donation for at least 6 monthsAvoid saliva of infected person.Vaccine is under research.

Pathophysiology

EBV replicates primarily in B-lymphocytes but also replicates in the epithelial cells of the pharynx and parotid duct. It is spread by saliva (i.e., coughing, sneezing, kissing, and sharing drinks and utensils). The incubation period is 4–8 weeks.EBV also has been isolated in both cervical epithelial cells and in male seminal fluid, suggesting that transmission also may occur sexually.

Etiology

EBV is a double-stranded DNA herpesvirus.

Commonly Associated Conditions

Streptococcal pharyngitis may be associated in 30% of the patients.

Diagnosis

History

Individuals between 10 and 30 years of age with a history of sore throat and significant fatigueThe syndrome is often heralded by malaise, headache, and low-grade fever before development of the classic triad of fever, tonsillar pharyngitis, and lymphadenopathy.

Physical Exam

Lymphadenopathy (100%): It is typically symmetric and more commonly involves the posterior cervical chain, but it also may become more generalized. It peaks in the 1st week and then subsides gradually over 2–3 weeks.Fever (98%)Pharyngitis (85%)Splenomegaly (50–60%)

Diagnostic Tests & Interpretation

Lab

Initial lab tests

Complete blood count (CBC): An increase in total lymphocyte >35% and atypical lymphocytes of at least 10%Elevated aminotransferases: Seen in the vast majority of patients but typically self-limitedHeterophile antibodies (monospot test): In 40% of patients, positive in 1st week; 90% of patients in 3rd week; may remain positive for 2 years for up to 20% of infected individualsEBV-specific antibodies: Viral capsid antigen (VCA): IgG and IgM peak at 3–4 weeks. IgG then declines but persists for life. IgM declines rapidly and is undetectable by 3 months.EB nuclear antigen (EBNA): Develops after 2 months and persists indefinitely; presence early in the course of illness excludes acute EBV infection.Early antigen (EA): IgG to EA is present at the onset of clinical illness and persists for 2–3 months.

Follow-Up & Special Considerations

In a patient with compatible syndrome and a negative heterophile antibody, the monospot test can be repeated because this test can be negative during the 1st week of clinical illness.EBV-specific antibodies should be determined if the patient has a repeatedly negative monospot test.

Imaging

Initial approach

Imaging not indicated initially

Follow-Up & Special Considerations

Ultrasound if clinically important to diagnose or follow splenomegalyCT scan of abdomen is preferred to rule out splenic rupture.

Differential Diagnosis

CytomegalovirusToxoplasmosisRubellaAdenovirusHerpesvirusesDrug adverse effectsStreptococcal pharyngitisViral tonsillitisDiphtheriaViral hepatitisLymphoma or leukemiaHuman herpesvirus 6RoseolaMumpsPrimary HIV infection

Pregnancy Considerations

Differentiating between IM caused by EBV and a similar syndrome owing to cytomegalovirus (CMV) or HIV infection often is not possible clinically, and it is particularly important if the patient is pregnant because CMV, HIV, and Toxoplasma infections can have significant adverse effects on pregnancy outcomes.

Pediatric Considerations

EBV acquired during childhood years is often subclinical.

Treatment

Medication

First Line

AcetaminophenNonsteroidal anti-inflammatory drugs (NSAIDs)LozengesGargling with 2% lidocaine (Xylocaine) solution

Second Line

Acyclovir (Zovirax): Not recommended; no clinical benefitCorticosteroids: Recommended in patients with significant pharyngeal edema that threatens respiratory compromiseSteroids are not recommended for routine treatment but do improve fever and hematologic abnormalities and may shorten length of infirmary stay (1)[B].

Additional Treatment

General Measures

Symptomatic treatment, the mainstay of care, includes adequate hydration, analgesics, antipyretics, and adequate rest. Complete bed rest is unnecessary.

Issues for Referral

Emergent ENT consultation for an impending airway obstructionSurgery consultation if suspicious of splenic rupture; the typical manifestations are abdominal pain and/or a falling hematocrit.

Additional Therapies

The preferred treatment for splenic rupture is nonoperative with intensive supportive care and splenic preservation, but some require splenectomy.

Surgery/Other Procedures

In-Patient Considerations

Initial Stabilization

Outpatient usually; 95% of patients recover uneventfully without specific complication.

Admission Criteria

Suspicion of splenic rupture or airway obstruction

Ongoing Care

Follow-Up Recommendations

A generalized maculopapular, urticarial, or petechial rash is seen occasionally. Rash is more common following the administration of ampicillin or amoxicillin.

Diet

Soft diet followed by gradually advanced diet if severe sore throat

Patient Education

For athletes planning to resume noncontact sports, training can be restarted gradually 3 weeks from symptom onset. For strenuous contact sports or activities associated with increased intraabdominal pressure, patient should wait a minimum of 4 weeks after illness onset (2)[B].There is no set time to go back to school or work. Individuals with IM tend to be most contagious during the incubation period, the 4–6 weeks before they get sick, and during the acute phases of their illness. Some people even may shed EBV when they are no longer sick.Because the EBV resides in the body for life, it can reactivate, but in most cases it won’t cause symptoms unless the immune system becomes severely compromised.

Prognosis

Fatigue, myalgias, and need for sleep may persist for several months after the acute infection has resolved.

Complications

Chronic EBV infections (i.e., chronic fatigue syndrome, the diagnosis of which remains highly controversial)Splenic rupture (rare, 0.1–0.5% of patients with proven IM)Hemolytic anemia (mild)ThrombocytopeniaHemolytic-uremic syndromeSeizures and other neurologic abnormalitiesNerve palsiesMeningoencephalitisReye syndromeMyocarditis/electrocardiographic (ECG) changesAirway obstructionAcute interstitial nephritis

References

1. Dickens KP, Nye AM, Gilchrist V, et al. Clinical inquiries. Should you use steroids to treat infectious mononucleosis? J Fam Pract. 2008;57:754–5.

2. Eichner ER. Sports medicine pearls and pitfalls–defending the spleen: return to play after infectious mononucleosis. Curr Sports Med Rep. 2007;6:68–9.

Additional Reading

Ebell MH. Epstein-Barr infectious Mononucleosis. Am Fam Phys. 2004;70:1279–87.

Putukian M, O’Connor FG, Stricker P, et al. Mononucleosis and athletic participation: an evidence-based subject review. Clin J Sport Med. 2008;18:309–15.

Torre D, Tambini R. Acyclovir for treatment of infectious mononucleosis: a meta-analysis. Scand J Infect Dis. 1999;31:543–7.

Wick MJ, Woronzoff-Dashkoff KP, McGlennen RC. The molecular characterization of fatal infectious mononucleosis. Am J Clin Pathol. 2002;117:582–8.

Codes

ICD9

075 Infectious mononucleosis

Snomed

271558008 infectious mononucleosis (disorder)

Clinical Pearls

IM should be suspected in patients 10–30 years of age who present with sore throat and significant fatigue, palatal petechiae, posterior cervical or auricular adenopathy, marked axillary adenopathy, or inguinal adenopathy.Patients with suspected IM, based on history and physical exam, should have a CBC with differential and a heterophile antibody test. In addition, patients also should have a diagnostic evaluation for streptococcal infection by culture or antigen test.In a patient with a compatible syndrome and a negative heterophile antibody test, the monospot test can be repeated because this test can be negative during the 1st week of clinical illness. EBV-specific antibodies (e.g., VCA IgM and IgG and EBNA) should be determined if the patient has repeatedly negative monospot tests.The presence of IgG EBNA or the absence of IgG and IgM VCA excludes primary EBV infection and should prompt consideration of alternative etiologies of a mononucleosis-like illness.An increase in monocytes does not suggest mononucleosis; an increase in total lymphocytes >35% and atypical lymphocytes >10% does suggest mononucleosis.