What is it?
Mononucleosis, or “mono,” is a viral infection caused by the Epstein Barr virus (EBV). Most adults are infected with EBV in their lifetimes, typically during adolescence or young adulthood. The virus is transmitted by oral secretions, leading to its common name “the kissing disease,” but sneezing and sharing cups or food may lead to transmission as well.

Symptoms
• Fever • Fatigue • Sore throat • Swollen lymph nodes • Rash

Sports Medicine Evaluation and Treatment
Athletes with the symptoms described above should seek further evaluation by a physician. A sports medicine physician will perform a thorough history and physical exam, looking for fever, swollen tonsils, swollen lymph nodes, and a rash. The physician will also perform an exam of the abdomen to evaluate for an enlarged spleen. The spleen is an organ in the upper left portion of the abdomen, and it is commonly swollen during a mono infection. Occasionally, the patient can have liver inflammation as well, and this can cause tenderness when pressing on the upper right portion of the abdomen. Liver inflammation can also cause itching, and yellowing of the skin (“jaundice”) and the whites of the eyes (“scleral icterus”). The physician may perform lab testing to evaluate for infection, and to look specifically for mononucleosis and liver inflammation. Ultrasound has been used to evaluate for spleen enlargement, but it is not necessary for the management of mono infections. The symptoms of mono can last for weeks to months. Interestingly, some EBV infections are relatively minor with minimal symptoms, and the athlete may never know he or she was ever infected. Treatment for the acute symptoms include rest, medications and interventions for inflammation and/or pain control (acetaminophen, ibuprofen, throat lozenges or sprays, and salt water gargles, for example), and adequate hydration. Mono is a viral infection, not a bacterial infection, so antibiotics are not effective treatments for the infection.

Prevention
The best way to prevent a mono infection is to avoid contact with the oral secretions of a patient who is infected. This includes avoiding the use of an infected person’s cup or water bottle, or avoiding eating his or her food. Frequent hand washing is also recommended.

Return to Play
Return to play can be difficult with mono infections. The spleen can enlarge during the infection, and be at an increased risk of rupturing. Most reported splenic ruptures have occurred in athletes returning to activity within three weeks of their illness. Based on this information, many sports medicine physicians restrict all exercise for the first three weeks of reported symptoms. After three weeks, and once the athlete’s fever is resolved and he or she is feeling better, consideration can be given to gradually returning to exercise and athletics. Return to full activity is often a shared decision between the physician, the athlete, and sometimes, the athlete’s family.

AMSSM Member Authors
Kyle V. Goerl, MD; Cindy J. Chang, MD

References
Hosey RG, Kriss V, Uhl TL, DiFiori J, Hecht S, Wen DY. Ultrasonographic evaluation of splenic enlargement in athletes with acute infectious
mononucleosis. Br J Sports Med. 2008;42(12):974–7. doi:10.1136/bjsm.2008.050807.

Lawee D. Mild infectious mononucleosis presenting with transient mixed liver disease: case report with a literature review. Can Fam Physician. 2007;53(8):1314–6. Available at: http://www.pubmedcentral.nih.gov/ articlerender.fcgi artid=1949255&tool=pmcentrez&rendertype=abstract.
Accessed March 26, 2014.

Putukian M, O’Connor FG, Stricker P, et al. Mononucleosis and athletic participation: an evidence-based subject review. Clin J Sport Med.
2008;18(4):309–15. doi:10.1097/JSM.0b013e31817e34f8.