Diagnosis of Glandular Fever
The diagnosis of glandular fever is based on a combination of clinical symptoms, physical examination, and specific laboratory tests. Because glandular fever shares symptoms with many other illnesses, accurate diagnosis requires careful evaluation, especially when the patient presents with a sore throat, swollen lymph nodes, and persistent fatigue.
Early diagnosis is important to manage the condition appropriately, advise on recovery time, and prevent complications such as spleen rupture. Fortunately, a number of simple blood tests can help confirm the presence of Epstein-Barr virus (EBV) or the immune system’s response to it.
Initial Clinical Assessment
Doctors typically begin by reviewing the patient’s:
Age (most cases occur between 15–25)
Recent exposure to someone with similar symptoms
Lifestyle habits (e.g., close contact, shared utensils, kissing)
Current symptoms, including:
Duration of sore throat and fatigue
Swollen glands
Appetite and sleep quality
Any rashes or antibiotic use
Physical examination usually reveals:
Red or swollen tonsils, often with white exudate
Swollen lymph nodes in the neck and possibly elsewhere
Fever
Occasionally, an enlarged spleen or liver tenderness
If these findings are consistent with glandular fever, further testing is ordered to confirm the diagnosis.
Blood Tests
Several blood tests help confirm glandular fever and exclude other causes of similar symptoms.
1. Monospot Test (Heterophile Antibody Test)
Detects antibodies that appear in response to EBV
Usually becomes positive within one week of symptom onset
Quick, inexpensive, and widely available
However, it may be:
Negative early in infection
Less reliable in children under 12
Occasionally false positive due to other conditions
2. Full Blood Count (FBC)
Glandular fever often causes:
Elevated white blood cells, especially atypical lymphocytes
Mild anaemia or low platelet count in some cases
The presence of >10% atypical lymphocytes supports the diagnosis strongly.
3. Liver Function Tests (LFTs)
Many individuals with glandular fever show:
Mildly elevated liver enzymes (ALT, AST)
In rare cases, jaundice or hepatitis-like symptoms
These abnormalities are usually temporary and resolve without treatment.
4. EBV-Specific Serology
If the monospot test is negative or inconclusive, EBV serology is more specific. It measures:
IgM antibodies to viral capsid antigen (VCA) – indicates recent infection
IgG antibodies to VCA – indicates past infection or long-term immunity
EBNA antibodies – appear several weeks post-infection and confirm previous exposure
The combination of these markers can determine whether the infection is:
Acute (recent)
Past or resolved
Unlikely to be EBV-related
Differential Diagnosis
Many other illnesses can mimic glandular fever, including:
Streptococcal tonsillitis
Cytomegalovirus (CMV) infection
HIV (acute seroconversion)
Toxoplasmosis
Viral hepatitis
Each of these conditions may cause similar symptoms, but blood testing helps differentiate them. In children, mild EBV infections may be mistaken for flu or general viral illness.
Imaging and Other Investigations
Imaging is rarely needed, but an ultrasound may be performed if:
There is concern about splenic enlargement
The patient reports persistent abdominal pain
There is suspicion of liver or gallbladder involvement
In hospital settings, imaging may be used to exclude other causes of lymph node swelling, such as lymphoma.
When to Repeat Testing
Occasionally, early tests may be inconclusive. Repeat testing is advised if:
Symptoms persist beyond two weeks without improvement
Initial tests are negative but symptoms strongly suggest EBV
The patient is immunocompromised or at risk of complications
In most cases, the diagnosis becomes clearer as the illness progresses.
Importance of Accurate Diagnosis
Confirming glandular fever allows:
Avoidance of unnecessary antibiotics
Guidance on rest and return to school or work
Education about avoiding contact sports due to spleen enlargement
Monitoring for complications, such as hepatitis, anaemia, or secondary infections
Misdiagnosis can lead to inappropriate treatment or unnecessary concern. For instance, mistaking EBV-related sore throat for bacterial tonsillitis may result in antibiotics, which not only don’t help but may cause a rash.
Conclusion | Diagnosis of Glandular Fever
The diagnosis of glandular fever involves recognising the clinical signs and confirming them with specific blood tests. Early detection ensures better management, appropriate activity restrictions, and reassurance for the patient. With time, most individuals recover completely, and complications are rare when the illness is correctly diagnosed and managed.
