Scarlet fever - Causes, symptoms and treatment. MF.

Scarlet fever is an acute, bacterial infection, with an aerogenic transfer mechanism, characterized by acute febrile onset and intoxication, as well as the presence of sore throat and rash on the skin. Only people are scarlet fever.

Scarlet fever has been known since ancient times, but the most colorful description arose in the Spanish name "garotillo", from the word garota - which means an iron collar, with the help of which the execution was executed by strangulation. From this name it becomes clear that the course of the disease was extremely severe, which was accompanied by suffocating cervical lymphadenitis.

Pathogen of scarlet fever

The causative agent of scarlet fever is β-hemolytic streptococcus of group A, Streptococcus pyogenes. To all characteristics peculiar to streptococci, specific features for the β-hemolytic group are added, which explains the features of the course of the disease: the expressed antiphagocytic defense is due to the presence of

capsules;
• antitoxic factor released during reproduction;

• an "immunoglobulin-Fc receptor" that interacts with a portion of the IgG molecule, as if blocking its active components;
• Protein M - is located in combination with the capsule and provides adhesion, as well as blockade of complement activation( this is a cascade of protective reactions);
• Erythrogenic toxin( most important) - inhibits the synthesis of antibodies and stimulates TNF( tumor necrosis factor), stimulates the development of toxic shock and rash;
• Leukocidin - selectively affects leukocytes.

Pathogenicity enzymes:

• fibrinolysin( streptokinase) - spreads fibrin clots and causes the spread of the pathogen along the bloodstream, to other organs and tissues;
• DNA-aza - destroys the cellular DNA;
• hyaluronidase - causes intercellular dissociation, which makes penetration of the pathogen unhindered, after adhesion.

Other factors of pathogenicity supplement the explanations for fever, intoxication and rashes:

• hemolysin( destroys red blood cells and has a cytotoxic effect on cardiomyocytes and phagocytes);
• enterotoxin( causes the clinic from the gastrointestinal tract);
• The presence of lipoteichoic acid explains the febrile state;
• Crossed antigens of the pathogen with antigens of tissues of various organs, which can subsequently lead to the development of autoimmune diseases, because newly synthesized specific antibodies against streptococcus will work against the following tissues with which there is similarity in structure: myocardium( myocarditis development), fibroblastsdefeat of the valvular apparatus of the heart), glomerular system of the kidneys( development of glomerulonephritis).A number of clinicians suggest that "cross-antigens", nothing more than direct tropism( selective defeat) of streptococcus to these tissues.

About sensitivity / susceptibility / prevalence / seasonality: β-hemolytic group A streptococcus is resistant to environmental factors. Withstands boiling for 15 minutes, it also shows resistance to disinfectants( it does not die right away, even under the action of chloramine).

Natural susceptibility is high, without sexual, age and geographical limitations, but the most frequent incidence is recorded in temperate and cold climates. Also characteristic autumn-winter-spring seasonality, especially in the intervals from November to December, and from March to April.

The timing of the seasonal increase in morbidity is strongly influenced by the organization of the team and its strength. Scarlet fever occurs in individuals who do not have immunity to toxigenic strains( species).After the transfer of the disease, a durable, long-lasting, antitoxic immunity is formed, but the allergic state to the scarlatinous allergen is also preserved, in the form of periodic temperature rises and characteristic rashes.

In addition to clinical facts that may not always be stable, the presence of this allergic readiness can be checked by placing intradermal samples - by the introduction of killed streptococci and, at the site of this introduction, redness / swelling and tenderness appear when the answer is positive. Passive congenital immunity is observed in children of the first year of life, up to 4 months from birth( the intensity of this immunity is determined by the reaction of Dick).

Causes of scarlet fever infection

Source - a sick person, carrier, as well as those suffering from streptococcal angina or nasopharyngitis. The transmission path is air-drop, contact-household( through contaminated household items) and contact.

Symptoms of scarlet fever

The incubation period of lasts 1-10 days, but more often 2-4 days. The beginning of this period is considered from the moment of introduction of the pathogen, to the first clinical manifestations. During this period, the pathogen gets on the mucous membrane of the nasopharynx, the genital organs, or through the damaged skin, at the place of implantation there occurs fixation and the beginning of vital activity, as well as the action of pathogenic factors that induce a vestigial necrotic focus in the attachment site and gradual spread through the blood and lymphatic vessels,giving rise to the next period - catarrhal( prodromal).The catarrhal period lasts about a week and is characterized by:

• acute onset with a rise in temperature and symptoms of intoxication( often accompanied by a single vomiting);
• Since the first days, in parallel with the rise in temperature and the development of intoxication, angina arises. It is often extensive, because it captures the entire lymph glotopharyngeal ring( palatine tonsils, pharyngeal tonsil, lingual tonsil at the root of the tongue, amygdala on eustachian tubes).Hyperemia of the oropharynx is so pronounced, and its edges are so sharp that the doctors previously called this condition "a symptom of a glowing pharynx."Also, on inflamed tonsils there are raids of different intensity - from small-to-large, to deep-spread ones.

Passing plaque on the tongue with scarlet fever

• Regional lymphadenitis - an increase in the anterior lymph nodes, which are painful and compacted on palpation.
• The first days of the disease, the tongue is covered with a thick white coating, but from the 4th day the plaque begins to descend and in its place is visible a bright red with crimson hue the surface of the tongue with clearly protruding papillae. This catchy color of the tongue persists for 2-3 weeks and is called a "symptom of the crimson tongue."
• By the end of the first day or the beginning of the second, against a background of fever, intoxication and sore throat, a rash begins that has features:
- a small-dot rash, first appears on the face, neck and upper parts of the trunk, then on the flexor surfaces of the extremities, on the sidesurfaces of the chest and abdomen. And also on the inner surfaces of the hips.
- In places of natural folds( ulnar, inguinal, axillary) the rash forms clusters in the form of dark red bands.

Lines on the folds of scarlet fever

- On the face the rash "does not touch" only the nasolabial triangle - it becomes pale( "Filatov's symptom"), the presence of this symptom is due to irritation with the toxin of the lower part of the trigeminal nerve that corresponds to the vasoconstrictor fibers.

Symptom Filatov( pale nasolabial triangle)

- when pressing on the site of the rash the rash disappears for a while, but then reappears - "a symptom of the palm."
- on 4-7 days the rash starts to turn pale, leaving no pigmentation after itself, but after it occurs exfoliation of the epidermis, especially on the heels and palms, notice large-scale peeling, which is explained by a more dense bond between the cells in these areas. Peeling takes 2 weeks
- the rash can be not only in the form of small spots, but also in the form of small vesicles( vesicle-papular rash).

Rash in scarlet fever is the main, most pathogenic symptom, and is explained by the action of erythrogenic toxin on small-calibrated vessels in both the skin and in other organs.

Rash on the palms of the scalar

As for the variability of the course of the disease, the symptoms can be very, very different, but the rash is always the same! At the first symptoms of scarlet fever, you need to call a doctor.

As it was said, after the disease, long / persistent / practically lifelong immunity is formed, but it is type-specific, that is, people will not get sick again with the same serovar streptococcus, but there will always be a risk of infection by another species.

Diagnosis of scarlet fever

1. According to clinical data on examination and clarification of complaints:
- acute onset with fever and intoxication
- acute catarrhal or catarrhal-purulent tonsillitis
- characteristic rash

2. Laboratory tests:
- OAK( ↑ Lc, Nf with a shift of the formula to the left, ↑ ESR).
- OAM and ECG - as additional methods, indicating the degree of compensation.
- The bacteriological method is performed by sowing bacterial material( smear from fauces / blood serum / blood) on blood agar, as a result of which there is an abundant growth of the pathogen, with the destruction of red blood cells around itself( hemolysis zone).
- Determination of antibody titre growth with the help of ELISA, which indicates the intensity of immunity or the stage of the disease( IgG-indicates the prescription of the disease, IgM - indicates the acute course of the process).

Treatment of scarlet fever

1. Etiotropic treatment consists in applyingnarrow-spectrum drugs of choice - erythromycin. If there is no such possibility, then there is a choice for a broad-spectrum group of antibiotics, cephalosporins. Treatment is possible at home at the age of a child over 3 years of age and the course of the disease in an easy form. In other cases, hospitalization is necessary. Duration of treatment is 7 days.

2. Local treatment consists of the use of such drugs as yoks, hexoral, stopangin, tartum verde( taking into account age restrictions - some drugs can be used from 3 years, some from 12, etc.).To local treatment, we can also include rinsing the throat with a solution of chamomile, furacilin 1: 5000, rotokan.

3. Anti-inflammatory and immunotropic therapy: lysobact, immunod.

4. Desensitizing treatment( antitoxic action): suprastin, tavegil, zirtek, etc.

5. Symptomatic means, in the presence of complications or concomitant weighting symptoms - the use of antipyretic, antitussive

Drugs are taken after consultation with a doctor.

Complications of scarlet fever

Lymphadenitis, otitis, sinusitis, mastoiditis, nephritis, arthritis with myocarditis, as well as complications of infectious-allergic origin( manifested as a rise in temperature to 38 ° C and the appearance of rashes of various nature on the extensor surfaces).But with timely treatment and adequate antibiotic therapy, the outcome is favorable.

Prevention of scarlet fever

Patients should be hospitalized with severe and moderately severe forms, especially from families where there are children under 10 years of age who have not had scarlet fever. Isolation should last 10 days from the moment of onset of the disease. In a children's institution where an outbreak is registered, the group is quarantined with medical supervision.

Specific prevention and treatment is not developed.

Therapist doctor Shabanova I.Е.