Infectious Mononucleosis

Airway first, every time - Airway obstruction from tonsillar and pharyngeal lymphoid edema occurs in 1% to 3.5% of cases and hits children hardest. Before induction, look and listen: tonsils meeting in the midline, muffled voice, drooling, stridor, or a patient who will not lie flat all say the obstruction is already partial. Plan for a spontaneous-ventilation induction with ENT present and a tracheostomy set open, not a routine dose of paralytic.

Steroids are the exception here, not the rule - Corticosteroids are not recommended in routine mononucleosis because of the immunosuppression concern, but airway obstruction is the accepted indication. If the airway is threatened, steroids belong in the plan alongside ENT involvement and definitive airway management.

Splenomegaly and rupture risk - The spleen is enlarged in up to half of patients with active disease, and rupture, though rare, is life-threatening. Palpate for it and read any recent ultrasound rather than assuming. Avoid anything that loads the abdomen: rough transfers, unsupported lateral or prone positioning, and abdominal insufflation while the patient is still in the acute phase.

Rupture presents as shock - Splenic rupture has been reported as early as six days after symptom onset. Abdominal pain with anemia and hemodynamic instability in a patient with mononucleosis is a ruptured spleen until proven otherwise — large-bore access, type and cross, and be ready for splenic artery embolization or splenectomy.

Timing elective surgery - Athletes are held from sport for a minimum of three weeks and until splenomegaly has fully resolved. The same logic applies to elective abdominal and laparoscopic surgery: if the spleen is still enlarged, the case can usually wait.

Check the counts and the liver enzymes - Expect lymphocytosis with a lymphocyte fraction above 50% and atypical lymphocytes above 10%; leukocytosis and thrombocytopenia also occur, and liver enzymes are frequently elevated. Send a CBC and LFTs before neuraxial anesthesia or any case where the platelet count matters.

Do not let amoxicillin through - A generalized maculopapular rash classically follows amoxicillin in mononucleosis, and other antibiotics can do the same. If surgical prophylaxis is ordered and the diagnosis is mononucleosis, flag the aminopenicillin before it goes in the line.

Myocarditis and the other complications - EBV causes myocarditis, encephalitis, hemophagocytic lymphohistiocytosis, pancreatitis, autoimmune hemolytic anemia, and acalculous cholecystitis. Encephalitis, psychosis, cranial nerve palsies, peripheral neuritis, and Guillain-Barré have all been reported. A young patient with mononucleosis and unexplained tachycardia or a new rhythm deserves an ECG before you take them back.

Rule out acute HIV - The most important entity to exclude is primary HIV infection, which presents with the same fever, lymphadenopathy, and pharyngitis. Mucocutaneous ulceration and a prominent rash point toward HIV rather than EBV. Which one it is changes the workup and the precautions the patient gets.

Know the limits of the monospot - The heterophile antibody test is close to 100% specific but only about 85% sensitive, and it is falsely negative early in the illness. A negative monospot in the first week does not clear the patient — repeat it, and send a rapid strep antigen or throat culture if the diagnosis is still open.

They shed for months - High-level oral shedding continues for a median of six months after illness onset. Gloves and standard precautions for airway manipulation apply well past the point the patient feels sick.

Infectious mononucleosis is the symptomatic form of Epstein-Barr virus (EBV) infection — a herpesvirus carried by roughly 95% of adults worldwide and spread in saliva. EBV infects oropharyngeal epithelium and then B lymphocytes, and the resulting lymphoid hyperplasia produces the clinical picture: fever, exudative tonsillar pharyngitis, posterior cervical lymphadenopathy, and hepatosplenomegaly. Peak incidence is 15 to 24 years old and the incubation period runs three to six weeks, so most patients cannot name an exposure.

Two features make it an anesthesia problem out of proportion to how mild it usually feels. Splenomegaly is present in up to half of patients with active clinical disease and is the substrate for splenic rupture. Pharyngeal and tonsillar lymphoid swelling obstructs the airway in 1% to 3.5% of cases, most often in children. Like every herpesvirus, EBV then persists for life with periodic reactivation.