Mononucleosis infecciosa

The familiar nickname for mononucleosis (or mono), “the kissing disease,” is somewhat misleading. While it is true that the Epstein-Barr virus (EBV) is responsible for 85 percent of mono diagnoses and can be contracted from another person’s saliva, a teenager might acquire it through drinking out of the same glass or sharing a straw with a person who is infected. Because mono also travels via droplets of mucus, exposure can also come from sitting too close to an EBV carrier in the midst of a coughing spell or from sneezing. 

An additional 10 percent of cases are caused by a second highly common virus from the herpes family: cytomegalovirus (CMV). Both CMV and EBV are opportunistic infections. They may stow away in a person’s body for an entire lifetime without incident. It is only when the immune system isn’t up to par that these viruses stir up trouble. “Once you’ve had mono, you usually don’t get it again,” explains Dr. Meg Fisher of St. Christopher’s Hospital for Children, in Philadelphia. “However, you may never stop being contagious.”

Mononucleosis can occur at almost any age, but the peak incidence is between ages fifteen and thirty. The rate of mono is high among college students, undoubtedly because they live in close quarters and tend to get run-down, particularly around finals time. 

Signs and Symptoms that Suggest Infectious Mononucleosis May Include:

• Fever (101 to 104 degrees F) and chills
• Sore throat
• Fatigue
• Enlarged lymph glands in the groin and armpit, and particularly in back of the neck
• Achiness
• Appetite loss
• White patches at the back of the throat
• Headache
• Hypersensitivity to light
• Puffy eyelids
• Enlarged spleen and/or liver
• Anemia
• Rarely, yellow jaundice or a rash

The early symptoms of mononucleosis are often nondescript in teenagers and young adults. Many exhibit no symptoms at all. Adults and young children may develop atypical symptoms, which complicates the diagnostic process. Most adolescents, though, come down with the classic quartet of features: sore throat, fever, fatigue and swollen glands. The lymph nodes, tender yet firm to the touch, can grow to the size of small eggs. 

How Infectious Mononucleosis is Diagnosed

Physical examination and thorough medical history, plus one or more of the following procedures:

• Complete blood count (CBC), looking for increased numbers of white blood cells called lymphocytes
• Epstein-Barr virus antibody-titer blood test, to detect the presence of EBV antibodies
• Heterophile antibody-agglutination blood test, to screen for heterophile antibodies, a type of antibody common to EBV; also called the Monospot Test

How Infectious Mononucleosis is Treated

Bed rest, plenty of fluids, well-balanced diet: There is no treatment for mono, per se. The therapies described in the table below are strictly for controlling the associated pain, fever and inflamed throat. The symptoms typically run their course within one to three weeks. Some youngsters, though, remain sick for months. “Mononucleosis is an incredibly variable disease,” says Dr. Fisher, a member of the American Academy of Pediatrics' committee on infectious diseases. Even after the early effects disappear, fatigue and weakness may linger for several weeks or more. 

Mono patients used to be confined to bed for four to six weeks, followed by another three months of limited activity. “Now,” says Dr. Fisher, “some teenagers feel better in a week and can go back to their full daily routines.” Well, almost. Half of all patients develop an enlarged spleen. The gland like organ, located in the upper-left portion of the abdomen, stores and filters the blood. If overexertion or traumatic impact to the body should cause the spleen to rupture, the internal hemorrhaging can be fatal. Fortunately, this complication is extremely rare. But as a precaution, adolescents recovering from mono must avoid heavy lifting, straining and competitive sports for approximately one month, or until their pediatrician gives them the go-ahead. A sudden, violent pain in the upper-left abdomen that doesn’t go away after five minutes warrants an immediate trip to the hospital emergency department or a phone call to the local emergency medical service.

Keeping Young Patients Comfortable: Treating the Common Symptoms of Mononucleosis