Mononucleosis

Physical exam

Your doctor may suspect mononucleosis based on your signs and symptoms, how long they've lasted, and a physical exam. He or she will look for signs such as swollen lymph nodes, tonsils, liver or spleen, and consider how these signs relate to the symptoms you describe.

Blood tests

Antibody tests. If there's a need for additional confirmation, a monospot test may be done to check your blood for antibodies to the Epstein-Barr virus. This screening test gives results within a day. But it may not detect the infection during the first week of the illness. A different antibody test requires a longer result time, but can detect the disease even within the first week of symptoms.

White blood cell count. Your doctor may use other blood tests to look for an elevated number of white blood cells (lymphocytes) or abnormal-looking lymphocytes. These blood tests won't confirm mononucleosis, but they may suggest it as a possibility.

There's no specific therapy available to treat infectious mononucleosis. Antibiotics don't work against viral infections such as mono. Treatment mainly involves taking care of yourself, such as getting enough rest, eating a healthy diet and drinking plenty of fluids. You may take over-the-counter pain relievers to treat a fever or sore throat.

Medications

Treating secondary infections and other complications. A streptococcal (strep) infection sometimes goes along with the sore throat of mononucleosis. You may also develop a sinus infection or an infection of your tonsils (tonsillitis). If so, you may need treatment with antibiotics for these accompanying bacterial infections.

Severe narrowing of your airway may be treated with corticosteroids.

Risk of rash with some medications. Amoxicillin and other antibiotics, including those made from penicillin, aren't recommended for people with mononucleosis. In fact, some people with mononucleosis who take one of these drugs may develop a rash. The rash doesn't necessarily mean that they're allergic to the antibiotic, however. If needed, other antibiotics that are less likely to cause a rash are available to treat infections that may go along with mononucleosis.