1. Infectious mononucleosis
Is a clinical syndrome characterized by pharyngitis,cevical lymphadenopathy, fever and lymphocytosis ,it is caused by Epstein Barr virus EBV ,subclinical infection in childhood is universal ,the virus is transmitted via direct contact through saliva. The incubation period is 4-6 weeks

2. CLASSICAL Clinical features
1-prodrome of headache,fever,and malaise.
2-severe pharyngitis which may include tonsillar exudate.
3-non tender anterior and posterior cervical lymphadenopathy.
4-palatal and periorbital edema, soft splenomegaly, inguinal and axillary lymphadenopathy and macular rash,petechiae ,erythema multiforme may occurred.

3. Clinical features
THE CLINICAL PICTURE IS DEPENDENT ON AGE .most infections in infant and young children either asymptomatic or present with mild pharyngitis with or without tonsillitis, in contrast 75% of infections in adolescents present as I.M
I.M in elderly present as nonspecific symptoms of prolonged fatigue, myalgia and malaise, the classical picture in elderly is rare.

4. Causes of death: ruptured spleen, thrombocytopenia causing hemorrhage, respiratory obstruction from pharyngeal edema.

5. Long term complications
1-nasopharyngeal carcinoma
2-Hodgkins disease
3-burkitts lymphoma

6. 1-paull –bunnell test and monospot test detect heterophiles antibody.
Investigations:
1-paull –bunnell test and monospot test detect heterophiles antibody.
2- atypical lymphocytes occurred also in mumps and rubella ,HIV,viral hepatitis.
3-serology.
4-Throat culture.

7. Heterophils antibodies is the antibodies that agglutinate sheep or horse RBC.
Leukocytosis is a rule in infectious mononucleosis mainly due to atypical lymphocytosis more than 10%,in I.M THE ATYPICAL LYMPHOCYTES IS USUALLY MORE THAN 20% ,thrombocytopenia and neutropenia might occurred. Elevation in transaminases is very common but clinical hepatitis is unusual.

8. Differential diagnosis of infectious mononucleosis(mononucleosis like syndrome)
1-CMV
2-HIV
3-TOXOPLASMOSIS
3-STREPTOCCOCAL PHARYNGITIS
4-VIRAL HEPATITIS
5-RUBELLA
5-LYMPHOMA
DRUGS(PHENYTOIN,CARBAMAZEPINE,SULPHONAMIDESA,MINOCYCLINE)

9. management 1- treatment is largely symptomatic
2-if throat culture confirm b-hemolytic streptococcus penicillin should be given
3-if penicillin is given to patient with infectious mononucleosis maculopapular rash occurred and should be avoided.
4- antiviral agents is not effective
5-short course of prednisolone 30 mg for 5 days is given only to patient with pharyngeal odema.

10. Indications of steroid
1- immune hemolytic anemia.
2-immune thrombocytopenia.
3-upper airway obstruction.
4-C.N.S COMPLICATION.

11. Common complication of infectious mononucleosis:
1- severe pharyngeal edema.
2- prolonged post viral fatigue.
3-antibiotic induced rash.
4-hepatitis.
5-jaundice.

12. Uncommon complications
1-polyneurotitis. 2-minengoencephalitis. 3-transverse myelitis. 4-cranial nerve palsy. 5-hemolytic anemia. 6-thrombocytopenia 7-pericarditis 8-myocarditis. 9-rare but significant is rupture spleen.