Mononucleosis, or mono, is caused by a virus. This infection is spread by saliva and close contact, thus acquiring the name, "the kissing disease." Mono can develop at any age group, but occurs most often in the ages of 15 to 17. The symptoms of mono feel like a typical viral illness at first, but will slowly worsen while additional symptoms emerge.
Initial Symptoms
The Mayo Clinic reports that the incubation period for mono is typically four to eight weeks, but can be shorter in young children. The medical symptoms of mono will start out as a general discomfort or ill feeling, fever, drowsiness, fatigue, headache, sore throat or a strep infection of the throat that isn't responding to antibiotics. The deterioration of these symptoms accompanied by additional signs is typical of a mono infection.
Swollen Lymph Nodes
A mono infection will cause the tonsils to become swollen and obtain a whitish-yellow covering. The lymph nodes in the neck and armpits will become swollen and painful.
Rash
A rash may occur if antibiotics are given while a mono infection is present. This may be pink in color and appear similar to a measles-type rash. Medline Plus advises against antibiotics administration unless a test is performed that shows a positive infection in addition to a mono infection, such as strep throat.
Other Symptoms
Physical examination by a physician may reveal a swollen liver or spleen while the abdomen is being palpated. Loss of appetite and muscle pain may be experienced. A blood test can check the white blood cell count (WBC). An increase in WBC activity is noted with mono, and under microscopic examination the white blood cells appear unusual and are called atypical lymphocytes. According to the University of Maryland Medical Center, atypical lymphocytes and abnormal liver function tests are characteristic medical symptoms of an active mono infection.
Less Common Symptoms
Additional symptoms may occur with a mono infection but are less frequently experienced. The symptoms may be chest pain, hives, yellowing of the skin or jaundice, stiff neck, nosebleed, rapid heart rate and a shortness of breath.
Duration of Symptoms
Medline Plus reports that symptoms of mono, such as fever, usually disappear within 10 days. The lymph nodes and spleen will be on the mend in about four weeks. Fatigue generally fades in a few weeks, but is common to last for two to three months. Individuals with a weakened or compromised immune system may experience a longer duration of symptoms and any possible complications that are associated with a mono infection.
