Your child has the telltale signs: extreme fatigue, swollen lymph nodes and a sore throat. Could it be mononucleosis (mono)?

A common and contagious viral infection, mono is usually caused by the Epstein-Barr virus (EBV). Other infections that can cause mono include rubella, hepatitis, adenovirus, cytomegalovirus, toxoplasmosis or HIV.

Most people are infected with EBV at some point in their lives, often by middle adulthood. Once infected, EBV stays in the body for life. It’s mostly inactive, but sometimes the dormant virus reactivates and is shed in the saliva and other bodily fluids. When this happens, it’s possible to pass it on to others who haven’t already been exposed, even if you don’t have symptoms.

How does someone get mono?

Mono is not as easy to catch as a common cold. Nicknamed the “kissing disease,” mono is spread through close contact, particularly contact with the saliva or mucus of an infected person. The virus also spreads from coughing, sneezing and sharing a straw, drinking glass, eating utensil or toothbrush. Less commonly, the virus is spread through breast milk, sexual intercourse and blood transfusions. 

Mono is most common in ages 15 to 30. That’s why we hear a lot about it in teens and college students. Still, anyone can get mono, including babies and young children. Mono is less common in adults over 40.

You can pass the virus to others through your saliva for a median duration of six months after symptoms subside.

How can you tell if your child has mono?

Symptoms of mono vary between age groups. Teens and young adults (ages 15-24) are most likely to have noticeable, classic mono symptoms that also tend to be more severe, while babies and young children often have no symptoms or very mild ones. Mono is sometimes mistaken for the common cold, the flu or strep throat.  Even with absent or minimal symptoms, the virus could still be carried in the saliva and be passed to others.

Symptoms may come on gradually about 4-6 weeks after someone is infected with the virus. When symptoms appear, they may be severe for a few days before slowly get milder. If symptoms linger or get worse, call your doctor.

Common symptoms of mono include:

• Constant fatigue or weakness
• Very sore throat (including white patches in the back of the throat)
• Swollen lymph nodes in the neck, groin, armpit
• Fever
• Headache and body aches
• Decreased appetite
• Night sweats, chills
• Skin rash

Less common but serious symptoms are swelling of the liver causing jaundice or swelling of the spleen (an organ in the upper left part of the belly) causing pain in the upper left part of the abdomen.About half of those with mono have enlargement of the spleen sometime during their illness.

The American Academy of Pediatrics  advises parents to call a doctor if your child is extremely fussy or drowsy, has a severe headache or sore throat, develops a rash, has a seizure or temperature of 104° Fahrenheit or above.

How long does mono last?

Most of the time, mono runs its course in a month or two, but the fatigue can last for several weeks or months. Children may recover faster, in one to three weeks. Once you've had mono, you will probably not get it again.

Complications from mono — although rare — can be very serious. Mono can enlarge the spleen for a few weeks or longer. An enlarged spleen can rupture and cause internal bleeding that can lead to death. Symptoms of a ruptured spleen include sudden, sharp severe pain in the upper left abdomen/left shoulder that feels worse when inhaling and sudden drop in blood pressure.

In rare cases, mono can also cause anemia, meningitis, hepatitis, heart inflammation (myocarditis), brain inflammation (encephalitis), Guillain-Barré syndrome and lymphoma, although cancer caused by EBV is rare.

How is mono diagnosed and treated?

Most doctors diagnose mono based on symptoms and a physical exam to check for common signs of the infection, such as swollen tonsils and an enlarged liver or spleen. Sometimes your doctor will order a blood test to look for antibodies that indicate an EBV infection (e.g., Monospot test).

There is no vaccine to protect against EBV or mono and, since it’s a viral disease (not bacterial), antibiotics don’t help. In fact, someone with mono who takes an antibiotic often ends up getting a rash.

Treatment for mono consists of plenty of rest, drinking lots of fluids (including cold liquids) to prevent dehydration, gargling with salt water, using throat lozenges and over-the-counter pain relievers for aches and pains. In severe cases of mono, steroid medications may decrease swelling in the throat.

While recovering from mono, contact sports and any type of rough play are typically off-limits for at least a month or longer until the swelling of the spleen subsides.

There are steps you can take to protect your kids from mono. To reduce the chance of getting the virus, or spreading it:

• Avoid close contact with anyone who has it.
• Don’t share drinking glasses, water bottles, eating utensils or lip balm/lipstick with others, even if they seem healthy.
• Wash hands well and often.
• Eat healthy, exercise daily and get good sleep.

Most of the time, mono goes away on its own, but if you’re ever concerned, contact your child’s doctor.

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