Healthy Living

Mono Rash: Get the Facts

Symptoms of Mono: Infectious Mononucleosis Treatment

What is mono?

Infectious mononucleosis or "mono" for short is a viral infection caused by the Epstein-Barr virus (EBV). Although mono can affect people of all ages, it usually occurs in teenagers. The virus is transmitted and spread through infected saliva. For this reason, the infection is regarded as the "kissing disease". 

Many people contract the virus during childhood, usually after their first birthday. However, mono may not be easily recognized in young children since they are often asymptomatic or only have mild symptoms. Once you get infected with the virus, you will probably be immune for the rest of your life. 

Have a question aboutInfectious Mononucleosis?Ask a doctor now

However, according to the Centers for Disease Control and Prevention (CDC), plenty of children in developed countries, such as the USA, do not get infected with mono during their early childhood years. Instead, mono is commonly seen in adolescents (high school students) and young adults (college students). 

Mono causes high fever, sore throat, and swelling of the lymph nodes in the neck. However, most cases of mono are usually mild and require minimal medical treatment. This viral infection tends to resolve on its own within 1-2 months. 

How does the rash develop?

Around 15-20 percent of mono cases have skin-related symptoms. Most of the time, a mono rash is similar to that of measles. The maculopapular (small, flat and red patches) rash is widespread and may last for a week or more. The rash usually begins on the trunk of the body and then spreads on the arms and face. 

The rashes also tend to develop when patients with mono are being given antibiotics, such as amoxicillin and cephalosporins. These rashes often indicate that the patients are hypersensitive to such antibiotics.



At times, streptococcal infections may also develop in patients with mono. Patients may also develop tonsillitis and sinus infections. Although mono is not typically serious, the following complications may develop in rare cases:

  • Jaundice (yellowing of the skin and whites of the eye)
  • Hepatitis (inflammation of the liver)
  • Splenomegaly (enlarged spleen)
  • Thrombocytopenia (abnormally low platelet count in the blood)
  • Anemia (low RBC count in the blood)
  • Myocarditis (inflammation of the heart)
  • Neurological complications (meningitis and Guillain-Barré syndrome)
  • Arthritis (inflammation of the joints)


Mono is caused by the Epstein-Barr virus (EBV), which belongs to the herpes virus family. EBV is one of the most common viruses that infect humans worldwide. The virus is easily transmitted through direct contact with the saliva and other body fluids of an infected person. It is commonly spread through kissing, sexual contact, and organ transplantation. You can also get the virus by inhaling droplets from an infected person's cough or sneeze and by sharing food or drinks with someone who has the virus.

If you are infected with EBV, the symptoms usually take about 4-8 weeks before they develop. Around 35-50 percent of mono cases in adolescents and adults cause noticeable symptoms. However, the infection is often undetected in young children.


Since the symptoms of mono resemble those of other viral infections such as hepatitis A, doctors usually rule out other possibilities through the following tests:

Physical Examination

During your doctor's appointment, you will be asked about your symptoms and how long you've had them. Individuals who are 15-25 years old may be asked if they have been in contact with anyone who has mono. For diagnosing mono, age is an important factor including common mono symptoms, such as sore throat, fever, and swollen glands. 

Your body temperature will be checked along with the glands in your armpits, neck, and groin. To check if your spleen is enlarged, the doctor might check the upper left portion of your abdomen. 

Blood Tests

  • Complete Blood Count (CBC): A CBC is a laboratory test that is usually requested by doctors to help them determine the severity of the infection. A complete blood count will show various levels of blood cells. A high lymphocyte count usually indicates mono. 
  • White Blood Cell (WBC) Count: If you have mono, your body tends to produce more WBCs to fight off the infection. Although an elevated WBC count cannot confirm a mono infection, its result often suggests a strong possibility of the infection. 
  • Monospot Test: According to the Centers for Disease Control and Prevention (CDC), the monospot test is not generally recommended when it comes to diagnosing mono cases. The reason is that the antibodies detected in the test can be due to other conditions instead of mono. Studies have also shown that this test may yield both false positive and false negative results. Although the test could indicate a case of mono, it cannot confirm an EBV infection. Even though the test does not always produce accurate results, it is quite easy to do. The results of this test are also released within an hour or less. 
  • EBV Antibody Test: If the monospot test is negative, the doctor might request for an EBV antibody test, which looks for specific EBV antibodies. An EBV antibody test can detect an early mono infection if you have symptoms. However, it may take a long time for the results to be released. 


Currently, there is no specific medication for the treatment of mono. Antibiotics are also ineffective in most viral infections including mono. Doctors usually recommend plenty of rest and fluid intake to help recover from the infection. 

Home remedies can be done when it comes to relieving a sore throat. One effective natural remedy is gargling using salt water. When it comes to fever and pain, over-the-counter pain relievers such as acetaminophen and ibuprofen can be used. Your doctor may also prescribe corticosteroid medications to relieve the swelling of the throat or tonsils. 

Seek immediate medical help if your symptoms get worse or when you have extreme abdominal pain. 

How long does a mono rash last?

Although everybody is different, the rash usually lasts for about 7 to 10 days. A mono rash often appears on the trunk and upper arms. After a few days, the rash spreads to the face and forearms. If the lesions become worse and become a problem, seek immediate medical help.