EBV is a herpes virus that only infects humans. The human body is often asymptomatic after infection with EBV, but if symptoms are present, symptoms of various systems can appear, with complex and varied clinical manifestations and varying degrees of urgency. The temperature can fluctuate widely and irregularly within 24 hours, but the lowest temperature is still higher than the normal body temperature, and sometimes the fever can also be persistent high fever, which can last for several days or weeks, or even 2-4 months, accompanied by chills; 2. The rash may appear as urticaria, maculopapular rash, erythema nodosum, scarlet fever-like rash, which usually fades in 3-7 days and leaves no trace; 3. Hepatosplenomegaly: A small number of patients may develop hepatosplenomegaly with mild pressure pain, resulting in abnormal liver function and even jaundice; 4. Swollen lymph nodes in the posterior occipital and cervical areas are most common, followed by lymph nodes in the axillae, groin, mediastinum, and mesentery. In addition, EBV infection may also lead to conjunctival congestion, rhinorrhea, and manifestations of the nervous, respiratory, and cardiovascular systems.