UMEM Educational Pearls

Return to Play After Infectious Mononucleosis (IM)

-Long incubation period make it difficult to determine source or onset

Presentation often atypical with nothing more than fatigue, decreased energy or decreased athletic performance.

DDX: Herpes simplex, HIV, CMV, toxo and strep (simultaneous infection may be seen in up to 30%)

Classic 3 to 5 day prodromal period (malaise, fatigue, anorexia)

Symptoms then progress into the classic “triad” of IM

                Fever, pharyngitis, lymphadenopathy (esp. posterior cervical nodes)

May also have posterior palantine petechiae ( of cases), jaundice, exudative pharyngitis, rash and splenomegaly)

Rash (10% to 40%), transient, generalized maculopapular, petechial or urticarial)

                Most commonly seen in patients treated with PCN antibiotics

Splenomegaly is an important complication in the athletic population

Mononucleosis makes the spleen susceptible to rupture (traumatic or spontaneous)

                - Lymphocytic proliferation enlarges the spleen beyond protection from the ribs

                - Physical examination has been shown to be unreliable for determining splenomegaly

                - Highest risk is in the first 21 days (rare after 28 days)

Ultrasound is the modality of choice

                -Splenomegaly peaks at 2 to 3 weeks and resolves in the majority between 4 to 6 weeks

Return to play is generally allowed after 4 weeks from diagnosis in the absence of splenomegaly and resolution of symptoms.