Epidemic myalgia is an acute infectious disease caused by enteroviruses, with a predominantly fecal-oral transmission mechanism. The clinical picture is characterized by an increase in body temperature, the appearance of attacks of pronounced spastic pain in the diaphragm, chest muscles, abdominal wall and extremities. Serological methods, detection of the pathogen’s RNA and the virus itself in the biomaterial are used for diagnosis. Additionally, general clinical studies are carried out. Etiotropic treatment has not been developed. Symptomatic therapy is prescribed.
ICD 10
B33.0 Epidemic myalgia
General information
Epidemic myalgia (“devil’s disease”, Bornholm’s disease, pleurodinia) is one of the possible variants of enterovirus infection. Rarely occurs in isolation. This type of pathology is widespread everywhere. In countries with a temperate climate, seasonality is characteristic with a peak incidence in the summer-autumn period. There is no such pattern in the countries of the equatorial belt. In 85% of cases, enterovirus infection is asymptomatic, only in 15% there is a manifestation of a pathological condition. Pleurodinia mainly affects older children and adults.
Causes
The causative agent is an RNA-containing virus belonging to the genus Enterovirus, family Picornaviridae. This genus includes many serotypes. One serotype of the pathogen can cause various forms of enterovirus infection. Epidemic myalgia is more often provoked by Coxsackie viruses in 1-6 serotypes, less often by Coxsackie A. Enteroviruses persist for a long time in cold water and soil, are resistant to freezing, but are quickly inactivated when heated above 50 ° C, dried, used for disinfection with solutions of iodine, formaldehyde and chlorine, ultraviolet irradiation.
The reservoir and source of infection can be water, soil and food contaminated with the pathogen, as well as a sick person and an asymptomatic virus carrier. The mechanism of transmission is fecal-oral, carried out through water, food and household contact pathways. The detection of the virus in the discharge from the upper respiratory tract suggests the possibility of infection by airborne droplets, but only some researchers adhere to this theory. Its opponents tend to believe that the virus enters the oral cavity with subsequent entry into the intestine and the implementation of the traditional mechanism of infection. Transplacental transmission of the pathogen is possible.
Pathogenesis
The virus enters the human body through the mucous membranes of the oral cavity, intestines and respiratory tract. The absence of a protein capsule contributes to the resistance of the pathogen to the action of gastric juice. Penetrating into epithelial cells and lymphoid tissue cells, the pathogen actively replicates. Approximately on the 3rd day of the disease, the infectious agent enters the bloodstream – viremia occurs.
With the blood flow, the microorganism spreads to organs and tissues. Depending on the tropicity of the virus, various structures are affected. Most often, the involvement of muscle tissue and the central nervous system in the process is noted. Possible damage to the pancreas, blood vessels of the eyes, lung tissue, heart, kidneys and liver with the development of appropriate clinical symptoms. Morphologically, edema, signs of inflammation and necrosis are determined in the affected tissues.
Symptoms
The incubation period is up to 10 days, on average about 3-4 days. The appearance of pronounced headaches, weakness and malaise is characteristic. Body temperature rises to febrile, and sometimes to hyperpyretic figures. Vomiting may occur at the height of the temperature reaction. Often there is an increase in cervical lymph nodes. Hyperemia of the pharynx and facial skin, granularity of the posterior pharyngeal wall is determined. Patients complain of scratching and sore throat. Rhinitis and conjunctivitis are detected.
Simultaneously with the appearance of general symptoms, signs of epidemic myalgia are increasing. Paroxysmal pains in various muscle groups are typical against the background of severe fever. The lesion of muscle tissue occurs according to the type of myositis. The attack lasts up to 10 minutes and is repeated at intervals of 30-60 minutes . The pain is mainly localized in the muscles of the back, limbs, chest and abdominal wall, increases with a change of position, breathing. To relieve the condition, patients begin to breathe superficially and often. On palpation, the affected muscle is edematous, painful. Pain and rigidity of the abdominal muscles during an attack can mimic a “sharp stomach”, but peritoneal symptoms remain negative.
After the attack, there is an increase in temperature, the appearance of myoglobinuria. After 2-3 days, a repeated rise in body temperature with the formation of a wave-like fever is characteristic. The duration of pleurodinia is about a week. This form is rarely detected in isolation, usually accompanied by other symptoms of enterovirus infection, such as exanthema, herpangina. After the disease, a persistent type-specific immunity is formed.
Complications
In most cases, Bornholm’s disease proceeds benign and ends in recovery. On the 5-6 day after the manifestation of epidemic myalgia, serous meningitis develops in some patients with the formation of characteristic clinical symptoms and laboratory signs, brain edema, epileptic seizures. In some cases, pneumonia and acute respiratory failure are noted.
In foreign literature, there is evidence of complications such as pericarditis and myocarditis. Sometimes, after an infection, paroxysmal tachyarrhythmias occur. Boys may have orchitis. When the muscles of the lower extremities are affected, transient gait disorders are rarely observed.
Diagnostics
During an objective examination, an infectious disease doctor pays attention to facial hyperemia, injection of sclera vessels, the presence of an appropriate enterovirus exanthema of the skin. It is possible to detect herpangina, pharyngitis, conjunctivitis. With the development of viral meningitis, positive meningeal symptoms are determined. According to the indications, consultations of a neurologist, surgeon and ophthalmologist are prescribed. The following clinical and laboratory methods are used to diagnose epidemic myalgia:
General laboratory techniques. In the general analysis of urine after an attack of myalgia, myoglobinuria is detected. When conducting a biochemical blood test, there is an increase in the activity of CPK and LDH. With the development of serous meningitis and involvement of CNS structures in the pathological process, corresponding changes in the cerebrospinal fluid, CT and MRI are detected.
Identification of infectious markers. Serological methods are used: the compliment binding reaction, the hemagglutination inhibition reaction. The most accurate diagnostic option is the detection of the pathogen RNA by PCR and the determination of the virus in cell culture. Blood, cerebrospinal fluid, nasopharyngeal flushes and fecal samples are used as the test material. False positive results are possible due to the wide spread of asymptomatic virus transmission.
Differential diagnosis is performed with acute respiratory diseases, pleurisy and angina pectoris. With pronounced tension of the abdominal muscles, it is necessary to exclude acute surgical pathology. It is important to distinguish enterovirus exanthema from chickenpox and aphthous stomatitis. With the development of epidemics, diagnosis is not difficult, but the variety of clinical manifestations of enterovirus infection causes difficulties in the occurrence of sporadic cases.
Treatment
Drugs for etiotropic treatment have not been developed. Symptomatic therapy is carried out. Patients are shown bed rest until the condition stabilizes, dry heat on the affected muscles. For the purpose of detoxification, infusion therapy or an abundant drinking regime is recommended. Nonsteroidal anti-inflammatory drugs, non-narcotic analgesics are used to relieve pain and reduce body temperature.
According to the doctor’s decision, sedative medications, glucocorticosteroids are used in short courses. When epidemic myalgia is combined with herpangina, gargling with disinfectant solutions is prescribed, with conjunctivitis – eye drops.
Prognosis and prevention
The prognosis for epidemic myalgia is relatively favorable, since this form of enterovirus infection proceeds in the form of mild and moderate forms without complications. Deaths as a direct result of pleurodinia are not reported. Medical examination after recovery is not required, it is carried out only in case of neurological complications.
Specific prevention has not been developed. Non-specific measures include compliance with the rules of personal hygiene and food culture. Of great importance is the implementation of sanitary and hygienic and anti-epidemic measures. Early detection and isolation of patients plays a special role. Quarantine is established for children who have been in contact with patients.