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Mononucleosis

Mono; Kissing disease; Glandular fever

Mononucleosis, or mono, is a viral infection that causes fever, sore throat, and swollen lymph glands, most often in the neck.

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Mononucleosis - photomicrograph of cells
Mononucleosis - photomicrograph of cells
Infectious mononucleosis #3
Acrodermatitis
Splenomegaly
Infectious mononucleosis
Mononucleosis - photomicrograph of cell
Gianotti-Crosti syndrome on the leg
Mononucleosis - view of the throat
Mononucleosis - mouth
Antibodies

Causes

Mono is often spread by saliva and close contact. It is known as "the kissing disease." Mono occurs most often in people ages 15 to 17, but the infection may develop at any age.

Mono is caused by the Epstein-Barr virus (EBV). Rarely, it is caused by other viruses, such as cytomegalovirus (CMV).

Symptoms

Mono may begin slowly with fatigue, a general ill feeling, headache, and sore throat. The sore throat slowly gets worse. Your tonsils become swollen and develop a whitish-yellow covering. Often, the lymph nodes in the neck are swollen and painful.

A pink, measles-like rash can occur, and is more likely if you take the medicine ampicillin or amoxicillin for a throat infection. (Antibiotics are typically not given without a test that shows you have a strep infection.)

Common symptoms of mono include:

Less common symptoms are:

Exams and Tests

Your health care provider will examine you. They may find:

Blood tests will be done, including:

Treatment

The goal of treatment is to relieve symptoms. Steroid medicine (prednisone) may be given if your symptoms are severe.

Antiviral drugs, such as acyclovir, have little or no benefit.

To relieve typical symptoms:

Also avoid contact sports if your spleen is swollen (to prevent it from rupturing).

Outlook (Prognosis)

The fever usually drops in 10 days, and swollen lymph glands and spleen heal in 4 weeks. Tiredness usually goes away within a few weeks, but it may linger for 2 to 3 months. Nearly everyone recovers completely.

Possible Complications

Complications of mononucleosis may include:

Death is possible in people who have a weakened immune system.

When to Contact a Medical Professional

The early symptoms of mono feel very much like any other illness caused by a virus. You do not need to contact a provider unless your symptoms last longer than 10 days or you develop:

Call 911 or the local emergency number or go to an emergency room if you develop:

Prevention

People with mono may be contagious while they have symptoms and for up to a few months afterwards. How long someone with the disease is contagious varies. The virus can live for several hours outside the body. Avoid kissing or sharing utensils if you or someone close to you has mono.

Related Information

Non-Hodgkin lymphoma
Seizures
Movement - uncoordinated
Guillain-Barre syndrome
Bell palsy
Hepatitis
Hemolytic anemia
Orchitis

References

Ebell MH, Call M, Shinholser J, Gardner J. Does this patient have infectious mononucleosis?: the rational clinical examination systematic review. JAMA. 2016;315(14):1502-1509. PMID: 27115266 pubmed.ncbi.nlm.nih.gov/27115266/.

Johannsen EC, Kaye KM. Epstein-Barr virus (infectious mononucleosis, Epstein-Barr virus-associated malignant diseases, and other diseases). In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 138.

Weinberg JB. Epstein-Barr virus. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 281.

Winter JN. Approach to the patient with lymphadenopathy and splenomegaly. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 159.

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Review Date: 3/10/2022  

Reviewed By: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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