Clinical presentation and catarrhal stage
The onset of the disease follows a flu-like scenario with pronounced intoxication syndrome. Patients complain of weakness, headache, and fever (body temperature can reach 39.5–40 °C).
The patient's characteristic appearance stands out: the face becomes puffy, and the eyelids swell. A prominent catarrhal syndrome develops, which includes:
- Eye involvement: photophobia, profuse lacrimation, pronounced conjunctival hyperemia, and scleral vessel injection.
- Respiratory tract: profuse mucous nasal discharge (rhinitis), sore throat, hoarseness, and a non-productive, hacking cough.
- Oropharynx: bright diffuse hyperemia ("velvety" mucosa), dry tongue with white coating.
A key diagnostic marker of the initial period is the pathognomonic Belsky-Filatov-Koplik sign. These are focal clusters of small whitish spots slightly rising above the hyperemic buccal mucosa opposite the lower molars. Painless pea-sized cervical lymph nodes may also be palpated.
Peak stage: staging of the exanthem
The transition to the rash stage usually occurs on the 6th day of the disease. A large, abundant maculopapular rash appears, which may coalesce but is located strictly on unchanged skin. Itching is not typical for a measles rash.
The main feature of the measles exanthem is its strict "top-to-bottom" spread sequence:
- The first elements always appear in the retroauricular area and on the face.
- Then the rash spreads to the trunk.
- Finally, the elements cover the distal extremities.
The evolution of the rash is accompanied by pigmentation and fine branny desquamation. As the rash spreads to the extremities, the elements on the face already begin to fade and desquamate. During the same period, dry and crepitant rales may be auscultated in the lungs, indicating involvement of the lower respiratory tract.
Laboratory diagnostics and differential diagnosis
During the initial examination, measles must be differentiated from influenza (especially in severe cases), parainfluenza, adenovirus infection, infectious mononucleosis, and toxic-allergic reactions to medications (e.g., antipyretics).
A mandatory step is a thorough collection of epidemiological history: contact history at work or school, history of past infections, and measles vaccination status.
The examination panel includes:
- Hemogram (CBC): characteristic leukopenia (e.g., drop to 3.4 × 10⁹/L), neutropenia, as well as relative lymphocytosis and monocytosis.
- Specific verification: performed via ELISA to detect specific anti-measles IgM class immunoglobulins.
Complications: measles meningoencephalitis
One of the most formidable complications is the development of meningoencephalitis and cerebral edema. As a rule, manifestation occurs at the end of the rash period (e.g., on the 5th day from the onset of the rash). The patient's condition sharply deteriorates against the background of persisting or recurring high fever.
Neurological symptoms:
- Dizziness, drowsiness, single or recurrent vomiting.
- Depression of consciousness (from lethargy to loss of consciousness and development of stage I coma).
- Development of seizure syndrome, myoclonus.
- Appearance of pathological reflexes, muscular hypertonus, and "floating" eye sign.
- Meningeal signs (nuchal rigidity, Kernig's sign).
Management tactics: The patient is subject to emergency hospitalization in the intensive care unit of an infectious diseases hospital. Intensive therapy aims to arrest the seizure syndrome and hyperthermia, correct metabolic disorders, and prevent cerebral edema. If necessary, the patient is transferred to mechanical ventilation.
For differential diagnosis (to rule out a bacterial etiology), cerebrospinal fluid (CSF) analysis is mandatory. Neuroimaging (CT, MRI, Echo-EG) and EEG to assess brain structure involvement, an ENT consultation, and chest X-ray are also indicated.
Briefly: answers to topical questions
What is the isolation period for a patient with measles?
The isolation period for a patient with measles depends on the presence of complications.
- Uncomplicated course — isolation is carried out until the 5th day, counting from the moment the rash appears.
- In the presence of complications — isolation is carried out until the 10th day.
To memorize the measles rash, use the "Face — Trunk — Extremities" rule. The exanthem seems to "flow down" from top to bottom, leaving pigmentation and peeling behind where it has passed.
Class and exam questions
What is the main difference between a measles rash and others?
The measles rash has a strict sequential appearance (top to bottom: from the face to the trunk and extremities), is located on unchanged skin, does not itch, and gradually transitions into the stage of pigmentation with peeling.
Which symptom allows making a diagnosis before the appearance of the rash?
A pathognomonic sign of the catarrhal period is Belsky-Filatov-Koplik spots — small whitish dots on the hyperemic buccal mucosa opposite the lower molars.
What is the cause of the sharp deterioration in condition with seizures at the end of the rash period?
This clinical picture indicates the development of a severe complication — measles meningoencephalitis, accompanied by cerebral edema.
What changes in the complete blood count are characteristic of measles?
The hemogram shows a viral pattern: leukopenia, neutropenia, as well as an increased proportion of lymphocytes and monocytes.
What else to study on this topic
- Pathogenesis of catarrhal syndrome development in measles infection.
- Differential diagnosis of measles, rubella, and infectious mononucleosis.
- CSF changes in viral and bacterial meningoencephalitis.
- Principles of intensive care for cerebral edema.
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