Historical background and epidemiology
The disease has been known to medicine since the mid-16th century, though for a long time it was mistaken for a mild form of smallpox. It was not until 1772 that Vogel identified chickenpox as an independent nosological entity.
The infection is ubiquitous and demonstrates an extremely high incidence rate. Second only to respiratory infections, it firmly holds third place in reporting frequency.
- Age structure: The majority of patients (80–90%) are children under 14 years of age.
- Statistics in the Russian Federation: Overall incidence shows an upward trend (about 900,000 cases are registered annually). Economic losses over a two-year period can reach 4–4.5 billion rubles.
- Features in adults: Although adults fall ill significantly less often, the infection is much more severe in them. The risk of life-threatening complications and death in older patients is 10–20 times higher. Official statistics regularly record fatal outcomes specifically among the adult population.
Clinical presentation
A typical moderate form of chickenpox has an acute onset. On the first day, intoxication syndrome prevails: a sharp increase in body temperature (up to 39.0 °C), chills, pronounced weakness, malaise, headache, and loss of appetite. On the second day of the illness, against the background of ongoing fever, a characteristic itchy rash begins to appear.
Physical examination of the patient reveals the following changes:
- Skin: Abundant polymorphic rash that invariably involves the scalp. The elements evolve: spot (macule) → nodule (papule) → blister with clear fluid (vesicle 2–5 mm in diameter) → isolated pustules → drying crust.
- Mucous membranes: Oropharyngeal involvement manifests as enanthema — rounded erosions surrounded by a red rim of hyperemia.
- Lymphatic system: Mild enlargement of the cervical lymph nodes is noted.
- Internal organs and CNS: As a rule, without gross pathology (abdomen soft, vesicular breathing, no meningeal signs). Tachycardia corresponding to the level of intoxication and fever is observed.
Diagnostic criteria and differential diagnosis
Establishing a clinical diagnosis in typical cases relies on clinical and epidemiological data and presents no difficulties.
Key reference points for establishing a diagnosis:
- Presence of pronounced intoxication syndrome at onset.
- Early eruption of specific exanthema without a strict sequential stage.
- False polymorphism — a crucial diagnostic marker. Elements at different stages of development (from spots to crusts) are simultaneously found in a single skin area.
- Presence of enanthema on mucous membranes.
- Thoroughly collected epidemiological history (contact with a patient with chickenpox or Herpes zoster within the last 21 days).
Exanthematous syndrome requires differential diagnosis. First of all, chickenpox should be distinguished from the generalized form of infection caused by herpes simplex virus, erythema multiforme, impetigo, and various forms of streptostaphyloderma.
Laboratory confirmation
If the clinical picture is insufficient, laboratory methods are employed. The material for study consists of nasopharyngeal swab-smears and vesicle contents.
| Parameter | Characteristic |
|---|---|
| Material for analysis | Nasopharyngeal discharge, skin vesicle contents |
| Staining method | Romanowsky-Giemsa |
| Specific marker | Intranuclear VZV inclusions (bodies) within syncytia |
Briefly: answers to topical questions
What specific complications of chickenpox can develop in adult patients?
Adult patients are at high risk of developing severe viral pneumonia. The risk group for this complication includes non-pregnant adults with the disease.
In general, the following groups of complications are distinguished during the infection:
- Specific (viral) complications — lesions of the central nervous system (encephalitis, meningoencephalitis, myelitis), cardiovascular system (myocarditis, endocarditis, pericarditis), and viral pneumonia.
- Bacterial (secondary) complications — caused by bacterial flora infection (purulent-inflammatory processes of the skin, subcutaneous tissue, mucous membranes, and secondary pneumonia).
What drugs or vaccines are used for specific prophylaxis of chickenpox?
A live attenuated vaccine is used for the specific prophylaxis of chickenpox. Sources indicate that routine immunization of the population is not carried out in Russia; vaccination is performed according to individual or epidemiological indications. The vaccination schedule is also indicated: the first dose at 1 year, revaccination at 6–7 years. The administration of donor immunoglobulin is also mentioned in sources as a preventive measure.
What drugs are used for etiotropic therapy of chickenpox?
The following medications are used for etiotropic (antiviral) therapy of chickenpox:
- Acyclovir — prescribed for severe forms and immunodeficiency orally (800 mg 5 times a day), and administered intravenously for CNS involvement.
- Vidarabine — used as an intravenous infusion (at a dose of 10-15 mg/kg per day).
- Specific immunoglobulin — administered in severe cases of the infection.
To easily remember the nature of the rash: False polymorphism is a «kaleidoscope» on the skin. All stages are present at one point in time: macules, papules, vesicles, and crusts, unlike the strict «top-down» staging of measles.
Class and exam questions
What is the phenomenon of false polymorphism?
This is the simultaneous presence on the skin of rash elements at different stages of evolution: spots, nodules, vesicles, and crusts. It occurs because new rashes appear in «waves».
What is the maximum observation period for contacts?
The incubation period of the virus is up to 21 days. It is within this timeframe that the epidemiological history must investigate contacts with patients having chickenpox or shingles.
What is searched for in smears during laboratory confirmation of the diagnosis?
Smear-smears stained with Romanowsky-Giemsa are examined for a specific sign: the presence of the chickenpox virus in the form of intranuclear inclusions within a multinucleated syncytium.
Why does chickenpox in adults require heightened attention?
Although adults fall ill significantly less often, the infection in them is often severe. The risk of developing dangerous complications and fatal outcomes in adults is 10–20 times higher than in children.
What else to study on this topic
- Pathogenesis of clinical symptoms and intoxication syndrome development.
- Severe complications and emergency conditions during VZV infection.
- Principles of diagnosis, etiotropic treatment, and prevention.
- Indications for patient hospitalization and discharge rules.
- Justification of the complete laboratory workup plan and analysis of immunograms.
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