Mononucleosis: Symptoms in Adults and Children, Rash and Sore Throat

Mononucleosis (infectious mononucleosis) is a viral infection that most often occurs in adolescents and young adults. The illness resolves without specific treatment but can last for weeks and be very draining. Below is what is known about the symptoms, rash, and sore throat in adults and children.

Mononucleosis: What Kind of Illness It Is and Who Gets It Most Often

Mononucleosis is caused by various viruses, most often the Epstein-Barr virus (EBV). It is widespread throughout the world: most people become infected with it at some point in their lives, but symptoms of mononucleosis appear in only some. People aged 15–24 are most often affected; among students, mononucleosis occurs especially often.

The viruses are transmitted through biological fluids, primarily saliva: through kissing, shared dishes, utensils, food, drinks, lip balm. Less commonly — through blood transfusion, organ transplantation, and through blood and semen during sexual contact. A person is contagious for approximately up to 7 weeks before symptoms appear and may remain contagious for several months after feeling better. There is no vaccine against mononucleosis.

Main Symptoms of Mononucleosis in Adults

The incubation period is usually 4–6 weeks. Symptoms develop gradually and rarely appear all at once. Headache and body aches are also possible, and less commonly — enlargement of the liver, spleen, or both organs.

• severe fatigue, up to exhaustion;
• high temperature, fever;
• sore throat;
• enlarged lymph nodes in the neck, armpits, head area, elbows, or groin;
• rash.

Most people recover within 2–4 weeks. In some people, fatigue persists for several more weeks; sometimes symptoms remain for six months or longer.

How Mononucleosis Manifests in Children and Young Children

In children, EBV infection usually occurs without symptoms. If symptoms are present, they are difficult to distinguish from other common childhood illnesses — for example, influenza. The typical picture of mononucleosis is more common in adolescents and young adults, while in young children symptoms may appear earlier than 4–6 weeks after infection.

Mononucleosis and the Throat: What a Sore Throat Looks Like

Sore throat is one of the main symptoms, sometimes very severe: swallowing is painful and difficult. On examination, the doctor checks the lymph nodes, tonsils, liver, and spleen — their enlargement provides a clue. A blood test helps rule out other illnesses with a similar picture, such as tonsillitis. Mononucleosis is caused by viruses, so antibiotics do not work against it; however, a bacterial infection such as streptococcal tonsillitis sometimes develops alongside it.

Rash in Mononucleosis and Rash After Antibiotics

Rash is among the possible symptoms of mononucleosis, and on dark skin it can be harder to notice. A separate matter is rashes associated with antibiotics: in people with mononucleosis, penicillin antibiotics such as ampicillin or amoxicillin can cause a rash, so they are not given for mononucleosis. The diagnosis is made based on symptoms, examination, and, if necessary, a blood test.

How the Diagnosis Is Confirmed and When a Doctor Is Needed

The diagnosis is made based on symptoms and physical examination, in some cases with the help of a blood test that checks for the presence of the Epstein-Barr virus and rules out other illnesses. Medical attention is sought for very high temperature, a feeling of heat, cold, or chills, severe sore throat, swelling on both sides of the neck, extreme fatigue and exhaustion, and also if the sore throat does not go away.

Most people recover without complications, but sometimes the following are possible: hepatitis and other liver problems, inflammation of the heart, kidney problems, decreased platelet levels and sepsis, neurological conditions (Guillain-Barré syndrome, Bell's palsy), splenic rupture, prolonged fatigue.

Mononucleosis by itself is not a reason to call an ambulance. Calling 103 or 112 is necessary if a person cannot swallow even their own saliva, has severe difficulty breathing — gasping, choking, unable to utter words — or has severe abdominal pain.

This material is for reference: it does not replace consultation with a doctor, who will examine the throat and lymph nodes and, if necessary, refer for a blood test.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer