Clinical features

The incubation period for this infection is about 4-8weeks (1).

Infants and young children may be asymptomatic or present with mild symptoms that are often difficult to recognize (2).

The classic triad of symptoms in glandular fever consists of (3):

• fever
• sore throat
• lymphadenopathy
  • posterior cervical adenopathy (1)
  • axillary adenopathy
  • inguinal adenopathy

In a study of 500 patients with glandular fever - at least 98 % had sore throat, lymph node enlargement, fever, and tonsillar enlargement (1).

Other clinical features seen in a patient with IM include:

• prodromal symptoms like chills, sweats, anorexia, fatigue, malaise, myalgias, headaches and abdominal fullness
• splenomegaly (soft) – seen in 50-60% of cases, peaks in the second week and resolves over the next 7–10 days (2,4)
• there may be a petechial haemorrhagic covering of the soft palate and whitish exudate covering the tonsils; the latter two features are suggestive of diphtheria
• a fine macular rash – may develop occasionally, the incidence of which is higher if the patient has been given ampicillin early in the illness skin rash - develops in 90 to 100% of IM patients who receive ampicillin (4)
• periorbital oedema (2)
• hepatomegaly – seen in 10-15% (2)
• jaundice (4)

Older adults are less likely to have sore throat and adenopathy but more likely to have hepatomegaly and jaundice (1)

Reference:

• (1) Mark H. Ebell. Epstein-Barr Virus Infectious Mononucleosis. Am Fam Physician 2004;70:1279-87,1289-90.
• (2) Charles PGP. Infectious mononucleosis. Australian Family Physician 2003;32(10)
• (3) Introduction. Infectious mononucleosis. Mayo Clinic-Mayo Foundation for Medical Education and Research.2008
• (4) Pulse 2003. Latest thinking on glandular fever