Pharyngoconjunctival fever: causes, symptoms, diagnosis, treatment

Pharyngoconjunctival fever is an acute viral disease that is not classified as epidemic. It is caused by adenovirus serotypes III, V and VII. All of them are resistant to low temperatures, are transmitted by contact and by airborne droplets. When analyzing the age composition of patients, it is revealed that they are mainly preschool and primary school children. The eye disease is preceded by a clinical picture of acute catarrh of the upper respiratory tract. This is expressed in an increase in body temperature to 38-39 ° C, the appearance of pharyngitis, rhinitis, tracheitis, bronchitis, and sometimes otitis. Patients complain of weakness, malaise, a feeling of dryness and scratching in the throat, cough, and runny nose. During examination, follicles can be seen on the back wall of the pharynx, sometimes in significant quantities, located on a hyperemic base, as well as grayish follicles on the uvula. The process is characterized by a clear line of demarcation of the inflamed mucous membrane of the pharynx from the normal mucous membrane lining the hard palate.

Adenoviruses were discovered by W. Rowe in 1953 in a tissue culture of adenoids and tonsils of children. Subsequently, 24 serological types were identified (at present, several dozen have been identified). Susceptibility to this infection is especially high in children from 6 months to 3 years of age. The sources of infection are sick people who excrete pathogens with secretions from the pharynx, respiratory tract, and feces. Adenovirus infections occur as sporadic diseases and epidemic outbreaks in children's institutions. According to statistics from the end of the 20th century, adenovirus infections among adults accounted for about 3% (7-10% in seasonal periods), among children - up to 23% (up to 35% in seasonal periods).

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Symptoms of pharyngoconjunctival fever

The symptoms of pharyngoconjunctival fever are variable: it can manifest itself mainly as catarrh of the upper respiratory tract (acute rhinitis, acute diffuse catarrhal pharyngitis, acute laryngitis and tracheitis), conjunctivitis (catarrhal, follicular, membranous), keratoconjunctivitis, pharyngoconjunctivitis fever, bronchitis and pneumonia. The most typical form is pharyngoconjunctival fever, which occurs with characteristic manifestations of adenovirus infection. Its causative agent is adenoviruses III, VII and VIII and other types.

The incubation period of pharyngoconjunctival fever is 5-6 days. The disease begins acutely with chills and a rise in body temperature to 38-40 ° C, moderate intoxication, catarrhal inflammation of the nasal mucosa, pharyngeal mucosa (clinical manifestations of various forms of acute pharyngitis are described below) and upper respiratory tract. There are profuse serous or serous-mucous discharge from the nose, cough in the first hours is dry, then wet with abundant sputum from the larynx and trachea. Body temperature of the continua type lasts up to 10 days. Catarrhal phenomena are usually persistent and long-lasting, especially runny nose. During this period, adenoviral damage to the anterior paranasal sinuses may occur with the rapid addition of bacterial microbiota and the development of secondary acute sinusitis. In some cases, two- or even three-wave fever is observed.

From the first day of illness or a little later, conjunctivitis develops - an obligatory sign of pharyngoconjunctival fever, which is usually unilateral at first, and then conjunctivitis of the second eye occurs. Membranous conjunctivitis is especially typical for pharyngoconjunctival fever, which determines the nosology of this form of adenovirus infection. Membranous plaques appear more often on the 4th-6th day of illness, initially in the area of the transitional fold, and then spread to almost the entire surface of the conjunctiva. The films are thin, delicate, white or grayish-white in color, sometimes lasting up to 13 days.

A common symptom of pharyngoconjunctival fever is an increase in submandibular lymph nodes. In the first days of the disease, vomiting and increased stool frequency sometimes occur. In the blood, in the first days of the disease, there are no significant changes, then moderate leukopenia, neutrophilia, and increased ESR.

An ENT specialist and an ophthalmologist, who most often supervise such patients, should keep in mind that one of the most formidable complications of pharyngoconjunctival fever is adenoviral pneumonia, which in some cases can develop in the first days of the disease and cause its main severity. Adenoviral pneumonia is characterized by a severe and often protracted course, severe intoxication, dyspnea and cyanosis, indicating the presence of toxic myocarditis. Physically, significant changes in percussion sound and abundant moist wheezing of various sizes are noted in the lungs. According to S. N. Nosov et al. (1961), S. N. Nosov (1963), during some outbreaks, significant mortality was observed among children under 1 year of age.

Against the background of general clinical manifestations or with some abatement (usually on the 2nd-4th day of the disease), unilateral or bilateral conjunctivitis occurs. Its clinical picture consists of hyperemia and roughness of the conjunctiva of the eyelids, the appearance of small follicles in the area of the lower transitional fold, and sometimes the appearance of filmy grayish deposits. The discharge from the conjunctival cavity is most often serous-mucous in nature.

A fairly typical symptom is the reaction of the preauricular lymph nodes. In some cases, especially in children with a history of allergies and diathesis, a more widespread reaction of the adenoid tissue is observed. This is expressed in the enlargement and soreness of the submandibular, cervical, subclavian and even axillary lymph nodes. Pediatricians believe that such a reaction should be assessed as a complex of the clinical picture of acute respiratory disease.

Against the background of the described clinical picture, corneal lesions often occur. The cornea is involved in the process simultaneously with the conjunctiva. Small-point superficial keratitis of epithelial localization occurs. Gray infiltrates are stained with fluorescein. Their presence can be verified and they can be differentiated from changes characteristic of corneal lesions in epidemic keratoconjunctivitis only by biomicroscopy. All clinical symptoms that form the basis of pharyngoconjunctival fever last no more than two weeks. Keratitis symptoms disappear without a trace.

The literature describes cases of relapse of pharyngoconjunctival fever. Relapse is usually provoked by a cold factor. It is possible that this is due to the absence of stable immunity during fever and that a repeated outbreak of the disease is caused by infection with an adenovirus of another serotype, to which the body has no immunity.

Diagnosis of pharyngoconjunctival fever

The diagnosis of adenovirus infection in the presence of a typical pharyngoconjunctival fever syndrome, especially with membranous conjunctivitis, can be made on the basis of clinical symptoms and taking into account epidemiological data.

Differential diagnostics are carried out mainly with influenza, and in the presence of membranous conjunctivitis - with diphtheria. An accurate diagnosis, the need for which arises in epidemic outbreaks in children's groups, is established by the method of virological research.

In practice, it is necessary to differentiate not only three forms of viral conjunctival lesions. First of all, it is necessary to try to distinguish them from conjunctivitis of bacterial origin, without which it is impossible to prescribe a reasonable pathogenetic treatment. Currently, bacterial conjunctivitis is most often caused by staphylococcal infection. Usually, they differ from viral conjunctivitis by a large amount of discharge from the conjunctival cavity and its different nature. The discharge very quickly becomes purulent. With bacterial conjunctivitis, as a rule, there is no general reaction in the form of increased body temperature, weakness and other sensations. They are not characterized by a follicular reaction from the conjunctiva (except for cases of follicular catarrh). In most cases, regional lymph nodes are not involved in the process.

In differential diagnostics, special attention should be paid to the examination of the cornea. A decrease in its sensitivity, the appearance of point (and in some cases, coin-shaped) infiltrates of epithelial or subepithelial localization should direct the doctor's diagnostic thought towards a viral infection. If differential diagnostics of conjunctivitis is difficult (bacterial or viral), as well as in cases of mixed infection, which can cause an unclear picture of the clinical manifestations of the process, it is advisable to conduct bacterioscopic (bacteriological) and cytological studies. These methods can be used in any medical institution with a minimum of laboratory equipment and a conventional light microscope. Detection of neutrophilic leukocytes and microbial flora (staphylococcus, pneumococcus) in a smear gives grounds for diagnosing bacterial conjunctivitis.

As for the cytological method of conjunctival examination, the technique is as follows. The procedure of taking a conjunctival scraping should be preceded by good anesthesia. It is caused by three-fold instillation of a 1% solution of dicaine into the conjunctival cavity. It is advisable to use another technique, using an application with dicaine to the area of the lower transitional fold. To do this, a cotton wick soaked in a 0.5-1% solution of dicaine is placed in the lower conjunctival fornix for 3-5 minutes. Such anesthesia makes the procedure of taking a scraping completely painless. If the material for examination must also be taken from the area of the upper transitional fold, a similar application can be made in the area of the upper conjunctival fornix. Once anesthesia is achieved, scrape conjunctival tissue from the desired area with a blunt microscope slide, a blunt Graefe knife or a platinum loop with pressure. After transferring the material to the microscope slide, fix it in ethyl alcohol for 10 minutes, then air dry. Stain according to Romanovsky for 40 minutes, rinse with tap water and air dry again. After this, proceed to microscopic examination.

In viral infection, lymphocytic and monocytic reactions occur, tissue cellular elements are greatly altered. Lysis and fragmentation of the nucleus, vacuoles in the cytoplasm of the conjunctival epithelium are observed. The cell membrane can be destroyed, the destroyed nucleus can be outside the cell. Sometimes cellular elements with destroyed membranes, merging, represent a giant cellular multinuclear structure, the so-called symplast. The presence of symplasts is very typical for viral infection. In order for the described picture not to be artificial, it is necessary to very carefully scrape the conjunctival tissue, allowing it to knead. As for hemorrhagic epidemic conjunctivitis, in this case, erythrocytes are found in large quantities in the conjunctival scraping, which indicates the toxic effect of the virus on the vessels. The mononuclear type of cellular exudate is characteristic, histiocytes are found.

The above changes, typical for a viral infection, are due to the fact that the viral infectious agent has the ability to reproduce only intracellularly - in a living organism or tissue culture. When it encounters a cell, the virus is adsorbed on it in accordance with its tropism for a particular tissue. After adsorption on cellular receptors, it is captured by the cellular membrane, which is intruded into the cell, forming a vacuole. Then the capsid is destroyed and the viral nucleic acid is released.

The nucleic acid of the virus restructures the vital activity of the cell in such a way that the infected cell is no longer able to continue its previous existence. It gives all its energy resources to the formation of viral progeny. In this case, the structures of the nucleus, nucleolus, and cytoplasm of the cell are used. All this, figuratively speaking, is the building material for the formation of initial viral particles. Hence, it is clear why it is during viral infection that the conjunctival cells lose their normal appearance, irretrievably losing their architectonics. Over time, the new progeny of viruses leaves the cellular structures. In this case, the cellular membrane ruptures and the cell nucleus and its nucleolus can exit into the surrounding space through the resulting defect. Thus, the cytological picture of the conjunctival tissue scraping can be of invaluable service in the diagnosis of a viral infection and the differential diagnosis of viral and bacterial infections.

To identify a specific pathogen of a viral infection, a method of immunofluorescence or fluorescent antibodies has been developed. Immunofluorescence is the luminescence in the ultraviolet light of a microscope of a biological object containing the antigen being studied after its preliminary treatment with specific antibodies labeled with a fluorochrome (fluorescein). At present, it is used only in large ophthalmological institutions that have a fluorescent microscope and the corresponding serums containing antibodies to various pathogens of viral infections. Nevertheless, a practicing ophthalmologist should have an idea of this diagnostic method. Its essence is that a stained serum (labeled antibodies, for example, to adenovirus serotype VIII) is applied to the conjunctival scraping material located on a glass slide. If a patient has acute epidemic adenoviral conjunctivitis, antibodies penetrate the virus (antigen) found in the cells of the conjunctival scraping. When examined under a fluorescent microscope, such a cell begins to fluoresce.

This diagnostic is an indisputable proof of viral infection and allows to determine the serotype of the virus or several viruses in case of mixed infection. Recently, up to 7 types of antibodies of colored blood serum have been used.

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Treatment of pharyngoconjunctival fever

If bacterial complications occur (sinusitis, bronchopneumonia, keratitis) - treatment in the appropriate specialized departments.

Prevention of pharyngoconjunctival fever

General preventive and anti-epidemic measures include isolating patients, limiting contact with them by non-service personnel, and allocating separate household items, dishes, and linen. Communication with patients should only be carried out while wearing a gauze mask. Items that were in use by the patient must be disinfected.