Scarlatina

Scarlet fever (Latin scarlatina) is an acute anthroponous infection with an aerosol mechanism of pathogen transmission, which is characterized by an acute onset, fever, intoxication, tonsillitis and a small-point rash. Scarlet fever is not common today.

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Epidemiology

The reservoir and source of infection are patients with tonsillitis, scarlet fever and other clinical forms of respiratory streptococcal infection, as well as healthy carriers of group A streptococci. The patient is most dangerous to others up to the 3rd week of illness. Carriage of group A streptococci is widespread in the population (15-20% of the healthy population); many of the carriers excrete the pathogen over a long period of time (months and years).

Scarlet fever is transmitted by aerosol (airborne) and contact (food and household contact). Infection occurs through close, long-term contact with a sick person or carrier.

The natural susceptibility of people to scarlet fever is high. Scarlet fever occurs in individuals who do not have antitoxic immunity when they are infected with toxigenic strains of streptococci that produce erythrogenic toxins of types A, B, and C. Postinfection immunity is type-specific; when infected with streptococci of type A of another serovar, a second infection is possible.

Scarlet fever is widespread, but is more common in regions with a moderate and cold climate. From 1994 to 2002, the majority of cases were children (96.4%). The prevalence of scarlet fever among urban populations is significantly higher than among rural residents. The overall level and dynamics of long-term and monthly scarlet fever incidence are mainly determined by the incidence of preschool children in organized groups. Every year, children attending child care institutions fall ill 3-4 times more often than children raised at home. This difference is most pronounced in the group of children in the first two years of life (6-15 times), while among children aged 3-6 years it is less noticeable. The highest rates of healthy carriage are noted among these same groups. The proportion of scarlet fever foci with one case of the disease in preschool institutions was 85.6%.

Scarlet fever incidence has a pronounced autumn-winter-spring seasonality. Seasonal incidence accounts for 50-80% of cases registered in a year. The minimum incidence is observed from July to August; the maximum - from November to December and from March to April. The timing of the seasonal increase in incidence is decisively influenced by the formation or renewal of an organized group and its size. Depending on the size of the group, the characteristics of its formation and functioning (large children's recreation centers, military units, etc.), the incidence of streptococcal infection increases after 11-15 days, and its maximum rates are noted 30-35 days after the formation of the group. In preschool children's institutions, an increase in incidence is usually recorded after 4-5 weeks, and the maximum incidence is on the 7-8th week from the moment the group is formed. In organized groups, which are renewed once a year, a single seasonal increase in scarlet fever is observed. With a double renewal, a double seasonal increase in the incidence is noted, which is especially characteristic of military organizations.

The peculiarities of scarlet fever epidemiology include the presence of periodic rises and falls in the incidence. Along with 2-4-year intervals, longer time intervals (40-45 years) are noted with a subsequent significant increase in the number of cases. As a rule, three large cycles of rise and fall in incidence are recorded in a hundred-year interval. In recent years, the minimum incidence rate characteristic of the interepidemic period has been reached (50-60 per 100 thousand of the population).

According to N.I. Nisevich (2001), the discovery of antibiotics and their widespread use had a significant impact on the nature of the course and outcome of scarlet fever in the mid-20th century.

Evolution of the course of scarlet fever in the 20th century depending on the treatment provided

Year	Complications, %	Mortality, %	Treatment
1903	66	22.4	Symptomatic
1910	60	13.5	-
1939	54	4.3	Sulfonamides
1940	54	2,3	Sulfonamides
1945	53	0.44	Penicillin therapy for severe forms
1949	28.7	0	Penicillin therapy for all patients
1953	4.4	0	Mandatory penicillin therapy for all patients and simultaneous booking of wards

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Causes scarlet fever

Scarlet fever is caused by group A beta-hemolytic streptococcus (S. pyogenes).

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Pathogenesis

The pathogen enters the human body through the mucous membrane of the pharynx and nasopharynx; in rare cases, infection is possible through the mucous membrane of the genitals or damaged skin (extrabuccal scarlet fever). An inflammatory-necrotic focus is formed at the site of bacterial adhesion. The development of infectious-toxic syndrome is caused by the entry of erythrogenic toxin (Dick's toxin) into the bloodstream, as well as the action of the peptide glycan of the streptococcal cell wall. As a result of toxinemia, generalized expansion of small vessels in all organs, including the skin and mucous membranes, occurs, and a characteristic rash appears. As a result of the production and accumulation of antitoxic antibodies during the development of the infectious process and their binding of toxins, the symptoms of intoxication weaken and the rash gradually disappears. At the same time, moderate signs of perivascular infiltration and edema of the dermis appear. The epidermis is saturated with exudate, and the epidermal cells become keratinized, which leads to peeling of the skin after the scarlet fever rash subsides. The large-plate nature of peeling in the thick layers of the epidermis on the palms and soles can be explained by the preservation of a strong connection between the keratinized cells in these areas.

Components of the streptococcal cell wall (group A polysaccharide, peptide glycan, M protein) and extracellular products (streptolysins, hyaluronidase, DNAase, etc.) cause the development of DTH reactions. autoimmune reactions. formation and fixation of immune complexes, disorders of the hemostasis system. In many cases, they can be considered the cause of myocarditis, glomerulonephritis, arteritis, endocarditis and other immunopathological complications. From the lymphatic formations of the mucous membrane of the oropharynx, pathogens enter the regional lymph nodes through the lymphatic vessels. where they accumulate, accompanied by inflammatory reactions with foci of necrosis and leukocyte infiltration. Subsequent bacteremia can cause microorganisms to enter various organs and systems and form purulent-necrotic processes in them (purulent lymphadenitis, otitis, lesions of the bone tissue of the temporal region, the dura mater, temporal sinuses, etc.).

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Symptoms scarlet fever

The incubation period of scarlet fever is 1-10 (usually 2-4) days. Scarlet fever is classified by type and severity. Scarlet fever with fever-intoxication syndrome, sore throat and rash is considered typical. Atypical scarlet fever - erased, extrapharyngeal (burn, wound, postpartum), as well as the most severe forms - hemorrhagic and hypertoxic. According to severity, mild, moderate and severe forms are distinguished. Typical symptoms of scarlet fever are, first of all, an acute onset. In some cases, already in the first hours of the disease, the temperature rises to high numbers, chills, weakness, malaise, headache, tachycardia occur, sometimes - abdominal pain and vomiting. With a high fever in the first days of the disease, patients are excited, euphoric, mobile or, conversely, sluggish, apathetic, drowsy. It should be emphasized that in the modern course of scarlet fever, body temperature may be low.

From the very beginning, patients complain of symptoms of sore throat when swallowing. Upon examination, there is bright diffuse hyperemia of the tonsils, arches, uvula, soft palate and back wall of the pharynx ("flaming pharynx"). The hyperemia is more pronounced than with ordinary catarrhal tonsillitis, and is sharply limited at the point where the mucous membrane transitions to the hard palate.

Follicular or lacunar tonsillitis may develop: mucopurulent, fibrinous or necrotic plaques appear on enlarged, sharply hyperemic and loosened tonsils in the form of separate small or, less commonly, deep and widespread foci. Regional lymphadenitis develops at the same time: the anterior cervical lymph nodes are dense and painful upon palpation. The tongue is coated with a grayish-white plaque, and by the 4th-5th day of the disease it clears up, acquires a bright red color with a raspberry tint ("raspberry" tongue); the papillae of the tongue are hypertrophied. In severe cases of scarlet fever, a similar "raspberry" color is also noted on the lips. By this time, the symptoms of tonsillitis begin to regress, but the necrotic plaques disappear much more slowly. From the cardiovascular system, tachycardia is determined against the background of a moderate increase in blood pressure.

Scarlet fever exanthema against the background of hyperemia of the skin occurs on the 1-2nd day of the disease. The rash is an important diagnostic sign of the disease. At first, small-point elements appear on the skin of the face, neck and upper body, then the rash quickly moves to the flexor surfaces of the limbs, the sides of the chest and abdomen, the inner thighs. In many cases, white dermographism is clearly expressed. An important sign of scarlet fever is the thickening of the rash in the form of dark red stripes in places of natural folds, for example, in the elbow, groin (Pastia's symptom), and axillary areas. Sometimes abundant confluent small-point elements are found, which creates a picture of continuous erythema. On the face, the rash is located on the bright hyperemic cheeks, to a lesser extent - on the forehead and temples, while the nasolabial triangle is free of rash elements and is pale (Filatov's symptom). When pressing on the skin of the palm, the rash in this area temporarily disappears (palm symptom). Due to the increased fragility of the vessels, small petechiae can be found in the area of joint folds, as well as in places where the skin is subject to friction or compressed by clothing. In addition to point, individual miliary elements appear in the form of small, pinhead-sized bubbles filled with transparent or turbid liquid. Endothelial symptoms (Rumpel-Leede tourniquet, "rubber band", Konchalovsky symptom) are positive.

Along with the typical scarlet fever rash, small vesicles and maculopapular elements can be noted. The rash may appear late, only on the 3rd-4th day of illness, or be absent. By the 3rd-5th day, the patient's health improves, the temperature begins to gradually decrease, the rash becomes pale, gradually disappears and by the end of the 1st-2nd week is replaced by finely scaly (on the palms and soles - large-plate) peeling of the skin.

The intensity of the rash and the time it takes for it to disappear vary. Sometimes, with a mild case of scarlet fever, the scanty rash disappears within a few hours of its appearance. The severity and duration of the skin peeling are directly proportional to the abundance of the preceding rash.

The toxic-septic form is considered a typical form of scarlet fever. Symptoms of scarlet fever in adults of this type are rarely detected. Characteristic are a rapid onset with hyperthermia, rapid development of vascular insufficiency (muffled heart sounds, drop in blood pressure, thready pulse, cold extremities), hemorrhages on the skin. In the following days, complications of an infectious-allergic (damage to the heart, joints, kidneys) or septic (lymphadenitis, necrotic tonsillitis, otitis, etc.) type occur.

Extrapharyngeal (extrabuccal) scarlet fever

The infection portal is the site of skin lesions (burns, wounds, birth canal, streptoderma foci, etc.). The rash tends to spread from the site of pathogen introduction. In this rare form of the disease, there are no inflammatory changes in the oropharynx and cervical lymph nodes. Lymphadenitis occurs near the entry portal of infection.

Latent forms of scarlet fever. Often found in adults. Characterized by weak intoxication, catarrhal inflammation in the oropharynx, scanty, pale, quickly disappearing rash. In adults, a severe course of the disease is possible - toxic-septic form.

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Complications and consequences

The pathogenesis of complications is based on three factors: allergy, reinfection and superinfection. The most common complications include purulent and necrotic lymphadenitis, purulent otitis, sinusitis, purulent arthritis, as well as complications of infectious-allergic genesis, more common in adults - diffuse glomerulonephritis, myocarditis, synovitis.

Indications for consultation with other specialists

• Otolaryngologist (otitis, sinusitis).
• Surgeon (purulent lymphadenitis).
• Rheumatologist (purulent lymphadenitis).

Diagnostics scarlet fever

Clinical diagnosis of scarlet fever is based on the following data:

• acute onset of the disease, fever, intoxication;
• acute catarrhal, catarrhal-purulent or necrotic tonsillitis;
• abundant, punctate rash in the natural folds of the skin.

Laboratory diagnostics of scarlet fever registers the following changes:

• neutrophilic leukocytosis with a left shift, increased ESR;
• abundant growth of beta-hemolytic streptococci when sowing material from the site of infection on blood agar;
• increase in antibody titers to streptococcal antigens: M-protein, A-polysaccharide, streptolysin O, etc.

Pure culture of the pathogen is practically not isolated due to the characteristic clinical picture of the disease and the widespread distribution of bacteria in healthy individuals and patients with other forms of streptococcal infection. For express diagnostics, RCA is used, which determines the streptococcal antigen.

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Differential diagnosis

Scarlet fever must be differentiated from measles, rubella, pseudotuberculosis, and drug dermatitis.

Measles is characterized by a catarrhal period (conjunctivitis, photophobia, dry cough), Belsky-Filatov-Koplik spots, staged appearance of rashes, large maculopapular rash against a background of pale skin.

In rubella, intoxication is weakly expressed or absent; enlargement of the posterior cervical lymph nodes is characteristic; a small-spotted rash on a background of pale skin, more abundant on the back and extensor surfaces of the extremities.

In drug-induced disease, the rash is more abundant near the joints, on the abdomen, buttocks. Polymorphism of the rash is characteristic: along with point rashes, papular, urticarial elements appear. Other clinical signs of scarlet fever are absent: tonsillitis, lymphadenitis, intoxication, characteristic appearance of the tongue, etc. Stomatitis often occurs.

In pseudo tuberculosis, intestinal dysfunction, abdominal pain and joint pain are often noted. The rash elements are rougher, located on a pale background. Thickening of the rash on the hands and feet ("gloves", "socks"), on the face, including the nasolabial triangle, can be noted. The liver and spleen are often enlarged.

When fibrinous deposits are detected, and especially when they extend beyond the tonsils, differential diagnostics of scarlet fever should be carried out with diphtheria.

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Treatment scarlet fever

Scarlet fever is treated at home, except in severe and complicated cases. The patient must stay in bed for 7 days. The drug of choice is benzylpenicillin at a dose of 15-20 thousand U/kg per day (5-7 days). Alternative drugs are macrolides (erythromycin 250 mg four times a day or 500 mg twice a day) and first-generation cephalosporins (cefazolin 50 mg/kg per day). The course of treatment is 5-7 days. If there are contraindications to these drugs, semi-synthetic penicillins and lincosamides are used. At home, preference should be given to tablet drugs (phenoxymethylpenicillin, erythromycin). Gargling with a 1:5000 furacilin solution, chamomile, calendula, and eucalyptus infusions is prescribed. Vitamins and antihistamines are indicated in normal therapeutic doses. Symptomatic treatment of scarlet fever is used according to indications.

Prevention of superinfection and reinfection is ensured by observing the appropriate anti-epidemic regime in the department: patients are hospitalized in small wards or boxes, isolated if complications arise; it is desirable to fill the wards simultaneously.

Clinical examination

Outpatient monitoring of those who have recovered is carried out for a month after discharge from the hospital. After 7-10 days, a clinical examination and control urine and blood tests are carried out, and an ECG is performed if indicated. If pathology is detected, a repeat examination is required after 3 weeks, after which the patient is removed from the outpatient register. If pathology is detected, the patient who has recovered is transferred to the observation of a rheumatologist or nephrologist.

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Prevention

In case of scarlet fever, the following patients are subject to mandatory hospitalization:

• with severe and moderate forms of infection;
• from children's institutions with round-the-clock stay of children (children's homes, orphanages, boarding schools, sanatoriums, etc.);
• from families with children under 10 years of age who have not had scarlet fever;
• from families where there are people working in preschool institutions, surgical and maternity wards, children's hospitals and clinics, milk kitchens, if it is impossible to isolate them from the sick person;
• when proper care at home is not possible.

A patient with scarlet fever is discharged from the hospital after clinical recovery, but not earlier than 10 days after the onset of the disease.

Procedure for admitting persons who have had scarlet fever and tonsillitis to children's institutions

• Convalescents from among children attending preschool institutions and the first 2 grades of schools are allowed to enter them 12 days after clinical recovery.
• An additional 12-day isolation of children with scarlet fever from closed children's institutions after discharge from hospital in the same institution is permissible if it has conditions for reliable isolation of convalescents.
• Convalescents from the group of decreed professions are transferred to another job for 12 days from the moment of clinical recovery, where they will not be epidemically dangerous.
• Patients with tonsillitis from a scarlet fever outbreak, identified within seven days from the date of registration of the last case of scarlet fever, are not admitted to the above-mentioned institutions for 22 days from the date of their illness (as are patients with scarlet fever).

When cases of scarlet fever are registered in a preschool institution, the group where the patient is found is quarantined for 7 days from the moment of isolation of the last patient with scarlet fever. Thermometry, examination of the pharynx and skin of children and staff are mandatory in the group. If a high temperature or symptoms of an acute upper respiratory tract disease are detected in any of the children, their immediate isolation from others is recommended. All persons who have been in contact with patients and have chronic inflammatory diseases of the nasopharynx are subjected to sanitization with tomicide for 5 days (rinsing or irrigation of the pharynx four times a day before meals). In the room where the patient is present, regular current disinfection is carried out with a 0.5% chloramine solution; dishes and linen are regularly boiled. Final disinfection is not carried out.

Children attending preschool groups and the first two grades of school, who have not had scarlet fever and have been in contact with a sick person at home, are not allowed into the child care facility for 7 days from the moment of their last contact with the sick person. If acute respiratory infections (tonsillitis, pharyngitis, etc.) are detected, children are examined for rash and suspended from classes (with notification of the local doctor). They are allowed into child care facilities after they have recovered and provide a certificate of antibiotic treatment. Persons of decreed professions who have been in contact with the sick person are allowed to work, but they are placed under medical observation for 7 days in order to promptly detect scarlet fever or tonsillitis.

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Forecast

Scarlet fever usually has a favorable prognosis if treated promptly.

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