DefinitionMononucleosis is a viral infection causing fever, sore throat, and swollen lymph glands, especially in the neck.See also: Infectious mononucleosis (acute CMV infection)Alternative NamesMono; Kissing diseaseCauses, incidence, and risk factorsMononucleosis, or mono, is often spread by saliva and close contact. It is known as “the kissing disease,” and occurs most often in those age 15 to 17. However, the infection may develop at any age.Mono is usually linked to the Epstein-Barr virus (EBV), but can also be caused by other organisms such as cytomegalovirus (CMV).SymptomsMono may begin slowly with fatigue, a general ill feeling, headache, and sore throat. The sore throat slowly gets worse. Your tonsils become swollen and develop a whitish-yellow covering. The lymph nodes in the neck are frequently swollen and painful.A pink, measles-like rash can occur and is more likely if you take the medicines ampicillin or amoxicillin for a throat infection. (Antibiotics should NOT be given without a positive Strep test.)Symptoms of mononucleosis include:DrowsinessFeverGeneral discomfort, uneasiness, or ill feelingLoss of appetiteMuscle aches or stiffnessRashSore throatSwollen lymph nodes, especially in the neck and armpitSwollen spleenLess frequently occurring symptoms include:Chest painCoughFatigueHeadacheHivesJaundice (yellow color to the skin)Neck stiffnessNosebleedRapid heart rateSensitivity to lightShortness of breathSigns and testsThe doctor or nurse will examine you. This may show that you have:Swollen lymph nodes in the front and back of your neckSwollen tonsils with a whitish-yellow coveringSwollen liver or spleenSkin rashBlood tests will be done, including:White blood cell (WBC) count – will be higher than normalMonospot test – will be positive for infectious mononucleosis.Antibody titer – tells the difference between a current and previous infectionTreatmentadvertisementThe goal of treatment is to relieve symptoms. Steroid medicine (prednisone) may be given if symptoms are severe.Antiviral drugssuch as acyclovir have little or no benefit.To relieve typical symptoms:Drink plenty of fluids.Gargle with warm salt water to ease a sore throat.Get plenty of rest.Take acetaminophen or ibuprofen for pain and fever.You should also avoid contact sports while the spleen is swollen (to prevent it from rupturing).Expectations (prognosis)The fever usually drops in 10 days, and swollen lymph glands and spleen heal in 4 weeks. Fatigue usually goes away within a few weeks, but may linger for 2 to 3 months.Complications Complications of mononucleosis may include:Bacterial infection of the throatHemolytic anemiaHepatitis with jaundice (more common in patients older than 35)Inflammation of the testicles (orchitis)Nervous system problems (rare), such as:Guillain-Barre syndromeMeningitisSeizuresTemporary facial paralysis (Bells palsy)Uncoordinated movements (ataxia)Spleen rupture (rare; avoid pressure on the spleen)Skin rash (Gianotti-Crosti syndrome – acrodermatitis ofchildhood)Death is possible in people who have aweakened immune system.Calling your health care providerThe initial symptoms of mono feel very much like a typical viral illness. It is not necessary to contact a health care provider unless symptoms last longer than 10 days or you develop the following:Abdominal painBreathing difficultyPersistent high fevers (more than 101.5F)Severe headacheSevere sore throat or swollen tonsilsWeakness in the arm or legsYellow discoloration of your eyes or skinCall 911 or go to an emergency room if you develop:Sharp, sudden, severe abdominal painSignificant difficulty swallowing or breathingStiff neck or severe weaknessPreventionPersons with mononucleosis may be contagious while they have symptoms and for up to a few months afterwards. How long someone with the disease is contagious varies. The virus can live for several hours outside the body. Avoid kissing or sharing utensils if you or someone close to you has mono.ReferencesFrye R, Bailey J, Blevins AE. Clinical inquiries. Which treatments provide the most relief for pharyngitis pain? J Fam Pract. 2011;60(5):293-294.Weber R. Pharyngitis. In: Bope ET, Kellerman RD, eds. Conn’s Current Therapy 2012. 1st ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 1.Jenson HB. Epstein-Barr virus. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed.Philadelphia, Pa: Saunders Elsevier; 2011:chap 246.Schooley RT. Epstein-Barr virus infection. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier;2011:chap 385.Review Date:5/15/2012Reviewed By:Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.