Mono may begin slowly with fatigue, a general ill feeling, headache, and sore throat. The sore throat slowly gets worse. Your tonsils become swollen and develop a whitish-yellow covering. The lymph nodes in the neck are frequently swollen and painful.

A pink, measles-like rash can occur and is more likely if you take the medicines ampicillin or amoxicillin for a throat infection. (Antibiotics should NOT be given without a positive Strep test.)

Symptoms of mononucleosis include:

• Drowsiness
• Fever
• General discomfort, uneasiness, or ill feeling
• Loss of appetite
• Muscle aches or stiffness
• Rash
• Sore throat
• Swollen lymph nodes, especially in the neck and armpit
• Swollen spleen

Less frequently occurring symptoms include:

• Chest pain
• Cough
• Fatigue
• Headache
• Hives
• Jaundice (yellow color to the skin)
• Neck stiffness
• Nosebleed
• Rapid heart rate
• Sensitivity to light
• Shortness of breath

During a physical examination, the doctor may find swollen lymph nodes in the front and back of your neck, as well as swollen tonsils with a whitish-yellow covering.

The doctor might also feel a swollen liver or swollen spleen when pushing on your belly. There may be a skin rash.

Blood work often reveals a higher-than-normal white blood cell (WBC) count and unusual-looking white blood cells called atypical lymphocytes, which are seen when blood is examined under a microscope. Atypical lymphocytes and abnormal liver function tests are a hallmark sign of the disease.

• A monospot test will be positive for infectious mononucleosis.
• A special test called an antibody titer can help your doctor distinguish a current (acute) EBV infection from one that occured in the past.