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Mononucleosis

Definition

Mononucleosis is a viral infection causing fever, sore throat, and swollen lymph glands, especially in the neck.

See also: Infectious mononucleosis (acute CMV infection)

Alternative Names

Mono; Kissing disease

Causes, incidence, and risk factors

Mononucleosis, or mono, is often spread by saliva and close contact. It is known as "the kissing disease," and occurs most often in those age 15 to 17. However, the infection may develop at any age.

Mono is usually linked to the Epstein-Barr virus (EBV), but can also be caused by other organisms 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. The lymph nodes in the neck are frequently swollen and painful.

A pink, measles-like rash can occur and is more likely if you take the medicines ampicillin or amoxicillin for a throat infection. (Antibiotics should NOT be given without a positive Strep test.)

Symptoms of mononucleosis include:

Less frequently occurring symptoms include:

Signs and tests

The doctor or nurse will examine you. This may show that you have:

  • Swollen lymph nodes in the front and back of your neck
  • Swollen tonsils with a whitish-yellow covering
  • Swollen liver or spleen
  • Skin rash

Blood tests will be done, including:

  • White blood cell (WBC) count - will be higher than normal
  • Monospot test  - will be positive for infectious mononucleosis.
  • Antibody titer  - tells the difference between a current and previous infection
Treatment

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

Antiviral drugs such as acyclovir have little or no benefit.

To relieve typical symptoms:

  • Drink plenty of fluids.
  • Gargle with warm salt water to ease a sore throat.
  • Get plenty of rest.
  • Take acetaminophen or ibuprofen for pain and fever.

You should also avoid contact sports while the spleen is swollen (to prevent it from rupturing).

Expectations (prognosis)

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

Complications
Complications of mononucleosis may include:
  • Bacterial infection of the throat
  • Hemolytic anemia
  • Hepatitis with jaundice (more common in patients older than 35)
  • Inflammation of the testicles (orchitis)
  • Nervous system problems (rare), such as:
  • Spleen rupture (rare; avoid pressure on the spleen)
  • Skin rash (Gianotti-Crosti syndrome - acrodermatitis ofchildhood)

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

Calling your health care provider

The initial symptoms of mono feel very much like a typical viral illness. It is not necessary to contact a health care provider unless symptoms last longer than 10 days or you develop the following:

  • Abdominal pain
  • Breathing difficulty
  • Persistent high fevers (more than 101.5°F)
  • Severe headache
  • Severe sore throat or swollen tonsils
  • Weakness in the arm or legs
  • Yellow discoloration of your eyes or skin

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

  • Sharp, sudden, severe abdominal pain
  • Significant difficulty swallowing or breathing
  • Stiff neck or severe weakness
Prevention

Persons with mononucleosis 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.

References

Frye R, Bailey J, Blevins AE. Clinical inquiries. Which treatments provide the most relief for pharyngitis pain? J Fam Pract. 2011;60(5):293-294.

Weber R. Pharyngitis. In: Bope ET, Kellerman RD, eds. Conn’s Current Therapy 2012. 1st ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 1.

Jenson HB. Epstein-Barr virus. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed.Philadelphia, Pa: Saunders Elsevier; 2011:chap 246.

Schooley RT. Epstein-Barr virus infection. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier;2011:chap 385.

Mononucleosis, photomicrograph of cells
This so-called "Downy cell" is typical of lymphocytes infected by EBV (Epstein Barr Virus) or CMV (Cytomegalovirus) in infectious mononucleosis. Downy cells may be classified as types I, II, or III. This is a type II Downy cell.
Mononucleosis, photomicrograph of cells
This is a lymphocyte that has been infected by the Epstein-Barr Virus (EBV) or Cytomegalovirus (CMV) in infectious mononucleosis and is referred to as a "Downy cell". Downy cells may be classified as types I, II, or III; this is a type I Downy cell.
Infectious mononucleosis #3
Infectious mononucleosis is caused by the Epstein-Barr virus. It is a viral infection causing high temperature, sore throat, and swollen lymph glands. Infectious mononucleosis can be contagious if the infected person comes in close or intimate contact with another person through saliva or sexual contact.
Acrodermatitis
Acrodermatitis enteropathica is a skin condition peculiar to children that may be accompanied by mild symptoms of fever and malaise. It may also be associated with hepatitis B infection or other viral infections. The lesions appear as small coppery-red, flat-topped firm papules that appear in crops and sometime in long linear strings, often symmetric.
Splenomegaly
Splenomegaly is an enlargement of the spleen.
Infectious mononucleosis
Swollen lymph nodes, sore throat, fatigue and headache are some of the symptoms of mononucleosis, which is caused by the Epstein-Barr virus. It is generally self-limiting and most patients can recover in 4 to 6 weeks without medications.
Mononucleosis, photomicrograph of cell
This picture shows large, atypical lymphocytes (white blood cells). These cells are seen in viral infections, most commonly caused by the Epstein-Barr virus (infectious mononucleosis), cytomegalovirus diseases, and occasionally infectious hepatitis. This is an example of a type I Downy cell.
Gianotti-Crosti syndrome on the leg
Gianotti-Crosti disease is also called acrodermatitis of childhood. These red, elevated lesions do not contain pus and can occur on the limbs, buttocks, face, and neck.
Mononucleosis - view of the throat
Infectious mononucleosis causes a sore throat, enlarged lymph nodes, and fatigue. The throat may appear red and the tonsils covered with a whitish material. Mononucleosis and severe streptococcal tonsillitis appear quite similar. Unless there are other findings to suggest mononucleosis, a throat culture and blood studies may be necessary to make an accurate diagnosis.
Mononucleosis - mouth
Infectious mononucleosis is caused by the Epstein-Barr virus. In teenagers and young adults, there is frequently a sore throat and red tonsils with whitish spots (exudate), as seen in this picture. Enlarged lymph nodes and fatigue are also common.
Antibodies
Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.

Review Date: 5/15/2012
Reviewed By: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

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