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Measles - Diagnosis
Last reviewed: 04.07.2025
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In conditions of low incidence, measles diagnostics are complex and include an assessment of the epidemic situation in the patient's environment, clinical observation over time, and serological testing. Typical measles with Filatov-Belsky-Koplik spots, cough, runny nose, conjunctivitis, and a rash that first appears on the head is easy to diagnose based on the clinical picture.
The main laboratory diagnostics of measles is a general blood test and serological blood testing using the RPGA, RTGA, RSC or ELISA methods.
- Complete blood count. Lymphopenia and neutropenia are characteristic, which is associated with the proliferation of the virus in leukocytes and their subsequent death. Leukocytosis indicates an accompanying bacterial infection.
- Serological methods of research. ELISA is the most sensitive, with its help the IgM titer is determined. Therefore, to confirm the diagnosis, it is enough to test the serum taken in the acute phase of the disease once, IgM become available for determination in the first 2 days after the appearance of the rash, IgG - after 10 days and reach maximum values after another 18-22 days. Before the appearance of the rash, the RNA of the virus is detected by the PCR method when examining blood and pharyngeal smears.
- Spinal tap. It is performed with subsequent analysis of cerebrospinal fluid if measles encephalitis is suspected. Lymphocytosis and increased protein levels are detected.
- RIF of respiratory tract secretion smears. Fluorescein-conjugated monoclonal antibodies are used to detect measles virus antigens. Giant multinucleated cells are found in smears stained by conventional methods. When croup develops, tonsil and nasal cultures are used to determine the diphtheria pathogen.
- Study of the blood coagulation system. Performed when hemorrhagic syndrome develops.
Instrumental diagnostics of measles (chest X-ray, echocardiography) is used when complications are suspected.
Differential diagnosis of measles is carried out with rubella, scarlet fever, infectious mononucleosis (when treated with ampicillin), and allergic rashes.
[ Indications for consultation with other specialists
In the event of otitis, laryngitis and laryngotracheitis, a consultation with an otolaryngologist with subsequent correction of therapy, as well as a physiotherapist, is indicated.
In case of prolonged conjunctivitis, development of keratoconjunctivitis, consultation with an ophthalmologist is necessary, and if encephalitis or meningoencephalitis is suspected, a neurologist.
Indications for hospitalization
Measles requires hospitalization in the following cases: severe and complicated forms of the disease, children from shelters, orphanages, dormitories, socially disadvantaged families.