Mononucleosis ============= þ Mononucleosis Names þ Mononucleosis Etiology and Epidemiology - The incubation period for mononucleosis is 30-40 days. Ref: A Practical Approach to Emergency Medicine 2nd edition p 321 þ Mononucleosis Rash - 5% of patients with infectious mononucleosis will get a generalized erythematous maculopapular rash. However, nearly 100% of those with infectious mononucleosis who are given ampicillin will get this rash. Ref: Tintinalli 3rd ed. p 508