Scarlet fever

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

[1], [2], [3], [4],

Epidemiology

The reservoir and source of infection - a patient with angina, scarlet fever and other clinical forms of respiratory streptococcal infection, as well as healthy carriers of group A streptococcus. The patient is most dangerous to those around him until the 3rd week of illness. The carriage of group A streptococci is widespread in the population (15-20% of the healthy population); many of the carriers excrete the pathogen for a long time (months and years).

Mechanisms for the transfer of scarlet fever - aerosol (airborne droplet) and contact (food and contact-household). Infection occurs in close long-term communication with a patient or a carrier.

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

Scarlet fever is ubiquitous, but more often it is found in regions with a temperate and cold climate. From 1994 to 2002 the bulk of the cases were children (96.4%). The prevalence of scarlet fever among the population of cities is much higher than among rural residents. The general level and dynamics of the long-term and monthly morbidity of scarlet fever basically determines the incidence of children of preschool age in organized collectives. Every year, children attending children's institutions fall ill 3-4 times more often than children who are brought up at home. This difference is most pronounced in the group of children of the first two years of life (6-15 times), while among children 3-6 years of age it is less noticeable. Among the same groups, the highest indicators of healthy bacterial transport are noted. Specific weight of foci of scarlet fever with one case of disease in children's preschool institutions was 85.6%.

The incidence of scarlet fever has a pronounced autumn-winter-spring seasonality. Seasonal incidence is 50-80% of diseases registered in the year. Minimal morbidity is noted from July to August; the maximum is from November to December and from March to April. The timing of seasonal increase in morbidity is decisively influenced by the formation or renewal of the organized collective and its strength. Depending on the size of the collective, its formation and functioning (large recreation centers for children, military units, etc.), the incidence of streptococcal infection increases after 11-15 days, and its maximum values are noted 30-35 days after the formation of the collective. In pre-school children's institutions, the incidence rate is usually recorded after 4-5 weeks, and the incidence rate is at 7-8 weeks from the moment the group was formed. In the organized collectives, which update occurs once a year, one-time seasonal increase in the incidence of scarlet fever is observed. With a two-fold renewal, two-time seasonal morbidity increases are noted, which is especially characteristic for military organizations.

The features of epidemiology of scarlet fever include the presence of periodic ups and downs in morbidity. Along with 2-4-year intervals, larger time intervals (40-45 years) are noted, followed by a significant increase in the number of cases. As a rule, three large cycles of rise and fall of incidence are recorded in the centenary period. In recent years, the minimum incidence rate, typical for the inter-epidemic period (50-60 per 100,000 population), has been reached.

In the opinion of N.I. Nisevich (2001), a significant influence on the nature of the course and the outcome of scarlet fever in the mid-20th century. Had the discovery of antibiotics and their wide application.

The evolution of scarlet fever in the XX century. Depending on the treatment

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	Penicillinotherapy in severe forms
1949	28.7	0	Penicillinotherapy for all patients
1953	4.4	0	Mandatory penicillin therapy for all patients and one-time tabulation of wards

[5], [6], [7], [8], [9], [10], [11],

Causes of the scarlet fever

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

[12], [13], [14]

Pathogenesis

The causative agent penetrates the human body through the mucous membrane of the throat and nasopharynx; In rare cases, infection through the mucous membrane of the genital organs or damaged skin (extra-buccal scarlet fever) is possible. In the place of bacterial adhesion, an inflammatory necrotic focus is formed. The development of the infectious-toxic syndrome is caused by the ingestion of the erythrogenic toxin (Dick toxin) into the bloodstream, as well as the action of peptidoglycan of the cell wall of streptococci. As a result of toxinemia, a generalized enlargement of small vessels occurs in all organs, including skin and mucous membranes, and a characteristic rash occurs. As a result of the development, accumulation of antitoxic antibodies in the development of the infectious process and the binding of toxins to them, the symptoms of intoxication become weaker and the rash gradually disappears. Simultaneously there are moderate signs of perivascular infiltration and edema of the dermis. The epidermis is impregnated with exudate, and the epidermis cells become cornous, which leads to peeling of the skin after the extinction of the scarlet fever. The large-lamellar 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.

The components of the cell wall of streptococcus (group A-polysaccharide, peptidoglycan, M protein) and extracellular products (streptolysins, hyaluronidase, DNA-ase, etc.) cause the development of HRT reactions. Autoimmune reactions. Formation and fixation of immune complexes, disturbances of the hemostasis system. In many cases, they can be considered the cause of the development of myocarditis, glomerulonephritis, arteritis, endocarditis and other immunopathological complications. From the lymphatic formations of the mucous membrane of the oropharyngeal pathogens along the lymphatic vessels enter the regional lymph nodes. 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 of the temporal sinuses, etc.).

[15], [16], [17],

Symptoms of the scarlet fever

The incubation period of scarlet fever is 1-10 (usually 2-4) days. Scarlet fever is classified according to the type and severity of the current. Typical is considered scarlet fever, flowing with febrile-intoxication syndrome, sore throat and rash. Atypical scarlet fever - erased, extrafarinating (burn, wound, postpartum), as well as the most severe forms - hemorrhagic and hypertoxic. By gravity, they release light, medium and heavy forms. Typical symptoms of scarlet fever are first and foremost an acute beginning. In some cases, even in the first hours of the illness, the temperature rises to high figures, chills, weakness, malaise, headache, tachycardia, and sometimes abdominal pain and vomiting. At a high fever in the first days of the disease, patients are excited, euphoric, mobile, or, conversely, sluggish, apathetic, sleepy. It should be emphasized that the current temperature of scarlet fever can be low.

From the very beginning, patients complain of symptoms of sore throat when swallowing. On examination, a bright diffuse hyperemia of the tonsils, arches, tongue, soft palate and posterior pharyngeal wall ("glowing pharynx"). Hyperemia is more pronounced than with conventional catarrhal angina, and is sharply limited at the site of transition of the mucous membrane to the hard palate.

It is possible to develop follicular or lacunar angina: on enlarged, sharply hyperemic and loosened tonsils, mucopurulent, fibrinous or necrotic plaques appear in the form of separate small or, more rarely, deep and widespread foci. At the same time, regional lymphadenitis develops: the anterior lymph nodes in palpation are dense and painful. The tongue is covered with a greyish-white coating, and by the 4-5th day of the disease it is cleared, acquires a bright red color with a raspberry tinge ("crimson" tongue); the papillae of the tongue are hypertrophied. In severe cases of scarlet fever, a similar "crimson" color is noted on the lips. By this time the symptoms of angina begin to regress, but necrotic plaques disappear much more slowly. From the side of the cardiovascular system, tachycardia is determined against a background of moderate increase in blood pressure.

Scarlet fever exanthema against the background of skin flare occurs in the 1-2 days of the disease. Rash is an important diagnostic sign of the disease. First, small-dot elements appear on the skin of the face, neck and upper body, then the rash quickly changes to the flexor surfaces of the extremities, the sides of the chest and abdomen, and the inner surfaces of the thighs. In many cases, white dermographism is clearly pronounced. An important sign of scarlet fever is a thickening of the rash in the form of dark red bands in places of natural folds, for example, in the ulnar groin (the symptom of Pastia). Axillary areas. Occasionally, abundant discharge small-dot elements are found, which creates a picture of continuous erythema. On the face, the rash is located on bright, hyperemic cheeks, to a lesser degree - on the forehead and temples, while the nasolabial triangle is free from the elements of the rash and is pale (Filatov's symptom). When pressing on the skin of the palm, the rash in this place temporarily disappears (a symptom of the palm). In connection with the increased fragility of the vessels, small petechiae can be found in the area of articular folds, as well as in places where the skin is rubbed or squashed by clothing. In addition to point-like, separate miliary elements appear in the form of small bubbles filled with a transparent or cloudy liquid. Endothelial symptoms (Rumpele-Leed harness, "gum", a symptom of Konchalovsky) are positive. 

Along with the typical scarlet fever, small vesicles and maculopapular elements can be noted. The rash may occur late, only on the 3-4th day of the disease, or absent. By the 3-5th day, the patient's well-being improves, the temperature begins to gradually decrease, the rash turns pale, gradually disappears and at the end of the 1-2 weeks it is replaced by small-scaly (on the palms and soles - large-bladed) skin peeling.

The intensity of the exanthema and the timing of its disappearance are different. Sometimes, with a light course of scarlet fever, a scanty rash disappears a few hours after the onset. The severity and duration of skin peeling are directly proportional to the abundance of the previous rash.

The toxic-septic form is attributed to the typical forms of scarlet fever. Symptoms of scarlet fever in adults of this type are rare. Characterized by a rapid onset of hyperthermia, rapid development of vascular insufficiency (deaf heart sounds, falling blood pressure, threadlike pulse, cold extremities), hemorrhages on the skin. In the days that follow, complications of infectious-allergic (cardiac, joint, kidney) or septic complications (lymphadenitis, necrotic tonsillitis, otitis, etc.) occur.

Extrapharyngeal (extra-buccal) scarlet fever

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

Scary forms of scarlet fever. Often found in adults. Characterized by weak intoxication, catarrhal inflammation in the oropharynx, scanty, pale, rapidly disappearing rash. In adults, the severity of the disease may be a toxic-septic form.

[18], [19], [20], [21], [22]

Complications and consequences

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

Indications for consultation of other specialists

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

Diagnostics of the scarlet fever

The 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;
• an abundant punctate rash in the natural folds of the skin.

Laboratory diagnostics of scarlet fever registers the following changes:

• neutrophilic leukocytosis with a leftward shift, increased ESR;
• abundant growth of beta-hemolytic streptococci when sowing material from the focus of infection on blood agar;
• the growth of antibodies titres to streptococcal antigens: M-protein, A-polysaccharide, streptolysin O, etc.

The pure culture of the pathogen is practically not isolated due to the characteristic clinical picture of the disease and the wide spread of bacteria in healthy individuals and patients with other forms of streptococcal infection. For rapid diagnosis, an RCA is used that determines the antigen of streptococci.

[23], [24]

Differential diagnosis

Scarlet fever should be differentiated from measles, rubella, pseudotuberculosis, medicinal dermatitis.

For measles, the catarrhal period (conjunctivitis, photophobia, dry cough), Belsky-Filatov-Koplik spots, the stage of the appearance of rashes, a large spotted-papular rash against the pale skin are characteristic.

With rubella, intoxication is poor or absent; characterized by an increase in supineus lymph nodes; melkopyatistaya rash against the background of pale skin, more abundant on the back and extensor surfaces of the extremities.

In case of medical illness the rash is more abundant near the joints, on the stomach, buttocks. The polymorphism of the rash is characteristic: along with the dotted eruptions, papular, urticarous elements arise. There are no other clinical signs of scarlet fever: sore throat, lymphadenitis, intoxication, a characteristic kind of tongue, etc. Often there is stomatitis.

When pseudotuberculosis is often noted intestinal dysfunction, pain in the abdomen and joints. Elements of the rash are coarser, located on a pale background. You can note the thickening of the rash on the hands and feet ("gloves", "socks"), on the face, including the nasolabial triangle. The liver and spleen are often enlarged.

When fibrinous plaque is detected, and especially when they go beyond the tonsils, differential diagnostics of scarlet fever should be performed with diphtheria.

[25], [26], [27], [28], [29], [30],

Treatment of the scarlet fever

Treatment of scarlet fever is carried out at home, excluding severe and complicated cases. The patient must comply with bed rest for 7 days. The drug of choice - benzylpenicillin at a dose of 15-20 thousand units / kg per day (5-7 days). Alternative drugs - macrolides (erythromycin 250 mg four times a day or 500 mg twice a day) and cephalosporins I generation (cefazolin 50 mg / kg per day). The course of treatment is 5-7 days. In the presence of contraindications to these drugs used semi-synthetic penicillins, lincosamides. At home, preference should be given to tableted preparations (phenoxymethylpenicillin, erythromycin). Assign rinsing of the throat with a solution of furatsilina 1: 5000, infusions of chamomile, calendula, eucalyptus. Vitamins and antihistamines are indicated in usual therapeutic doses. Symptomatic treatment of scarlet fever is used according to the indications.

Prevention of superinfection and reinfection is ensured by observing the corresponding anti-epidemic regimen in the department: patients are hospitalized in small chambers or boxes, isolated in case of complications; it is desirable to simultaneously fill the chambers.

Clinical examination

Dispensary observation for those who have been ill spend a month after discharge from the hospital. After 7-10 days, a clinical examination and control tests of urine and blood are performed, according to the indications - ECG. If a pathology is detected, a second examination is necessary after 3 weeks, after which the patient is removed from the dispensary register. When a pathology is discovered, the patient is referred to a rheumatologist or nephrologist.

[31], [32], [33], [34],

Prevention

In case of scarlet fever, patients must be hospitalized:

• with severe and moderate forms of infection;
• from children's institutions with a round-the-clock stay of children (children's homes, orphanages, boarding schools, sanatoria, etc.);
• from families where there are children under the age of 10 who have not had scarlet fever;
• from families where there are persons working in children's pre-school establishments, surgical and maternity wards, children's hospitals and polyclinics, dairy kitchens, if they can not be isolated from the sick;
• if it is impossible to take proper care at home.

The discharge of a patient with scarlet fever from a hospital is performed after a clinical recovery, but not earlier than 10 days after the onset of the disease.

The procedure for admission of persons who have had scarlet fever and sore throat to children's institutions

• Reconvalvesents from among children attending preschool institutions and the first 2 classes of schools are admitted in them 12 days after clinical recovery.
• An additional 12-day isolation of patients with scarlet fever from children from closed children's institutions after discharge from the hospital in the same institution, if it has conditions for reliable isolation of convalescences.
• Reconvalvesents from the group of decreed professions from the moment of clinical recovery for 12 days are transferred to another job, where they will be epidemic not dangerous.
• Patients with angina from the focus of scarlet fever, revealed during seven days from the date of registration of the last case of scarlet fever, are not admitted to the above-mentioned institutions within 22 days from the date of their illness (as well as patients with scarlet fever).

When a scarlet fever is registered in a preschool institution, a quarantine is imposed on the group where the patient is found, for a period of 7 days from the moment of isolation of the last patient with scarlet fever. In the group, it is necessary to conduct thermometry, examination of the throat and skin of children and staff. If any of the children have a fever or symptoms of an acute upper respiratory tract infection, they should immediately be isolated from others. All persons who have been in contact with patients and who have chronic inflammatory diseases of the nasopharynx are subjected to a salivation with thymicide for 5 days (rinse or watering the pharynx four times a day before meals). In room. Where there is a patient, conduct a regular current disinfection with 0.5% solution of chloramine; dishes and linen regularly boiled. Final disinfection is not carried out.

Children who attend pre-school groups and the first two classes of the school who have not had scarlet fever and have been in contact with the sick at home are not admitted to the children's institution within 7 days from the last communication with the patient. When an ARI (angina, pharyngitis, etc.) is detected, the children are examined for rash and removed from the practice (with the notification of the district doctor). In children's institutions they are admitted after they recover and provide a certificate of treatment with antibiotics. The persons of the jobs that have been in contact with the patient are allowed to work, but they are followed up with medical supervision for 7 days to promptly identify scarlet fever or sore throat.

[35], [36], [37], [38],

Forecast

Scarlet fever usually has a favorable prognosis provided timely treatment.

[39], [40]