Difference Between Mononucleosis and Strep Throat

Sore throat is a common presentation in the clinical practice. Mild sore throat is usually caused by viral infections such as in common cold, but if it is severe, has to consider mononucleosis or streptococcal infection as differential diagnosis. This article points out the differences between these two conditions, which would be helpful in making the diagnosis.


It is a viral infection commonly seen in young adults. The disease is caused by Epstein-Barr virus (EBV), which is transmitted by respiratory droplets or contact with infected saliva. Incubation period may vary from 4-5 weeks. The disease is not highly contagious, so that isolation is not necessary.

Clinically the patient presents with sore throat associated with fever, anorexia, malaise, lymphadenopathy especially posterior cervical, palatal petechiae, spleenomagelly, and clinical or biochemical evidence of hepatitis. Unnecessary use of antibiotics such as penicillin may cause severe rash.

Patient should be investigated with a blood film, which shows atypical lymphocytes with lymphocytosis. Other tests include monospot or paul-Bunnell test and the immunological studies.

This is a self-limiting condition, which resolves in 2weeks time. So the management is largely symptomatic. Aspirin gargles can be given to relieve sore throat. Prednisolon is given in case of severe pharyngeal edema. Antibiotics should be avoided because they commonly induce a macula-papular rash.

Complications of this disease is rare but may develop depression, malaise, thrombocytopenia, splenic rupture and hemorrhage, upper air way obstruction, secondary infections, pneumonitis, lymphoma and auto immune haemolyticanaemia.

In most of the patients, the condition gets resolved completely; only 10% can get chronic relapsing syndrome.

Strep Throat

It is a bacterial infection caused by group A streptococci, which is commonly seen in children and teens. The disease is transmitted by direct contact with an infected person; thus, crowding becoming a major risk factor.

Clinically the patient may present with sore throat with associated fever, lymphadenopahty, and other constitutional symptoms. Tonsillitis is a feature. Tonsils may be enlarged and red and white patches may be seen on the surface.

Throat culture with sensitivity is the gold standard in the diagnosis of the streptococcal pharyngitis. Complications of the disease include rheumatic fever, retropharyngeal abscess and post streptococcal glomerulonephritis.

Management of the disease involves antibiotics where the patient feels better in 1-2 days.


What is the difference between mononucleosis and strep throat?

• Mononucleosis is a viral infection while strep throat is a bacterial infection.

• In mononucleosis patient develops severe sore throat that can be associated with lymphadenopahty, palatal petechiae, splenomegally and mild hepatitis while sore throat in strep is usually associated with tonsillitis.

• Throat culture is the gold standard in diagnosing streptococcal infection while lymphocytosis with atypical lymphocytes and positive monospot test may suggest mononucleosis.

• Mononucleosis is a self-limiting condition where antibiotics should be avoided, but strep throat should be treated with antibiotics.

• Complications are rare with mononucleosis but, in strep throat, they can develop rheumatic fever and post streptococcal glomerulonephritis.