Infectious mononucleosis syndrome

Cervical lymphadenopathy in infectious mononucleosis (marked by arrows)

Infectious mononucleosis syndrome is a disease that is clinically very similar to infectious mononucleosis, but does not meet all laboratory criteria and is characterized by a lack of heterophile antibodies. Clinically, it manifests as cervical lymphadenopathy followed by other symptoms that are less common (such as throat-related findings, hepatosplenomegaly).

Causative agents

• human Cytomegalovirus,
• rarely HIV, rubeola virus, adenoviruses, Toxoplasma gondii, HHV-6 and HHV-7 .

Source, transmission and incubation period depend on the causative agent. We determine the diagnosis based upon lymphadenopathy, atypical lymphocytes in peripheral blood, increase in aminotransferases enzymes in the blood without increase in lactate dehydrogenase at the same time and serological evidence of the causative agent. The prognosis is good, we are able to treat the symptoms (rest and liver disease diet).

The differentiation of etiological agents is not very significant, except for the recognition of primary HIV infection, which has a crucial importance for the patient and his surroundings.

Comparison of infectious mononucleosis and IM syndrome

CRITERIA	Infectious mononucleosis	Infectious mononucleosis syndrome
Agens	EBV (Epstein-Barr virus)	CMV, HIV, rubeola, toxoplasma
Lymphadenopathy	✔	✔
Atypical lymphocytes	✔	✔
Aminotransferases	elevated	elevated
L-lactate dehydrogenase	elevated	normal
Heterophile antibodies	elevated	×
Hepatic syndrome	✔	could be present
Throat-related findings	✔	could be present