Myositis is an inflammatory process in skeletal muscles. It can affect any muscle. The most characteristic common symptom is local pain in the muscle (or muscles), which increases with movements and palpation. Over time, due to the protective tension of the muscles, there may be a limitation of the volume of movements in the joints. With the prolonged course of some myositis, there is an increase in muscle weakness, and sometimes even atrophy of the affected muscle. The diagnosis is established on the basis of complaints and examination results. According to the indications, additional studies are prescribed. The treatment regimen is selected individually and depends on the form of the disease and the cause that caused it.
ICD 10
M60 Myositis
General information
Myositis is an inflammatory process in one or more skeletal muscles. The etiology of the disease is characterized by a rare variety. Most often, various infections (ARI, influenza, chronic tonsillitis) become the cause of the development of disease. In addition, pathology can occur in autoimmune diseases, due to parasitic infections, exposure to toxic substances, etc. The disease can occur both acutely and chronically. In some cases, the skin is involved in the process. Under certain conditions (local infection), the development of a purulent process in the muscle is possible.
The severity can vary greatly. The most common myositis – cervical and lumbar – develop at least once in a lifetime in almost all people. Often they remain undiagnosed, because patients take the manifestations for an exacerbation of cervical or lumbar osteochondrosis. But there are also severe forms that require hospitalization and long-term treatment.
Causes
The first place in the incidence rate is occupied by muscle lesions caused by the most common viral infectious diseases (ARI, influenza). Less often, myositis occurs with bacterial and fungal infections. It is possible both the direct impact of microorganisms on the muscles, and the development of this disease due to the action of toxins.
Systemic autoimmune diseases are not the most common cause of myositis, but they cause the development of the most severe forms of the disease. As a rule, the most severe muscle damage occurs with polymyositis, dermatomyositis and Muncheimer’s disease (ossifying myositis). Other systemic diseases (rheumatoid arthritis, scleroderma, systemic lupus erythematosus) are characterized by moderate myositis. Among the parasitic infections that most often cause myositis are toxoplasmosis, echinococcosis, cysticercosis and trichinosis.
The cause of the development of myositis can be the effect of various toxic substances, both permanent and relatively short-term. Thus, toxic myositis often develops with alcoholism or cocaine addiction. Unstable muscle lesions can also occur when taking certain medications (alpha-interferon, hydroxychloroquine, colchicine, statins, etc.). Such lesions are not always inflammatory in nature, therefore, depending on the symptoms, they can be attributed to both myositis and myopathy.
Favorably occurring myositis of mild, less often moderate severity may occur after hypothermia, injuries, muscle cramps or intense physical exertion (especially in patients with untrained muscles). Pain, swelling and weakness for several hours or several days in the latter case is caused by small tears of muscle tissue. In extremely rare cases, usually with extreme physical exertion, the development of rhabdomyosis – necrosis of muscle tissue is possible. Rhabdomyosis can also occur with polymyositis and dermatomyositis.
In people of certain professions (violinists, pianists, PC operators, drivers, etc.), myositis can develop due to an uncomfortable body position and prolonged load of certain muscle groups. The cause of purulent myositis may be an open injury with infection, a focus of chronic infection in the body or local infection due to violation of hygiene rules during intramuscular injections.
Classification
Taking into account the nature of the process in surgery, neurology, traumatology and orthopedics, acute, subacute and chronic myositis are distinguished, taking into account the prevalence – local (limited) and diffuse (generalized). In addition, there are several special forms of myositis:
- Infectious non-purulent myositis. It occurs with viral infections (enterovirus diseases, influenza), syphilis, brucellosis and tuberculosis. Accompanied by severe muscle pain and noticeable general weakness.
- Acute purulent myositis. It is usually a manifestation of septicopyemia or a complication of a chronic purulent process (for example, osteomyelitis), characterized by the presence of purulent and necrotic processes in the muscles. It is accompanied by local edema and pronounced local pain. Possible increase in body temperature, chills and leukocytosis.
- Myositis in parasitic infections. It occurs as a result of a toxic-allergic reaction. It is accompanied by pain, swelling and muscle tension. Possible malaise, slight fever, leukocytosis. It often has a wave-like flow caused by the life cycle of parasites.
- Ossifying myositis. As a rule, it occurs after injuries, but it can also be congenital. A distinctive feature is the deposition of calcium salts in the connective tissue. The shoulders, thighs and buttocks are most often affected. It is accompanied by muscle weakness, progressive muscular atrophy, muscle compaction and calcification. The pain is usually indistinct.
- Polymyositis. Multiple muscle lesions. Polymyositis usually develops in systemic autoimmune diseases, is one of the most severe forms of myositis. Accompanied by pain and increasing muscle weakness. In some cases, with such myositis, muscle atrophy and the disappearance of tendon reflexes are possible. In children, it can be combined with damage to the lungs, heart, blood vessels and skin. In men over the age of 40, in half of cases, simultaneous formation of tumors of internal organs is noted.
- Dermatomyositis (Wagner-Unferricht-Hepp disease, Wagner’s disease). Dermatomyositis is a systemic disease, accompanied by damage to the skin, skeletal and smooth muscles, as well as internal organs.
Myositis symptoms
Most often, a local process (a lesion of one or several, but not many muscles) develops in the muscles of the neck, lower back, chest and lower legs. A characteristic symptom of myositis is aching pain, which increases with movement and palpation of muscles and is accompanied by muscle weakness. In some cases, with myositis, there is a slight redness (hyperemia) of the skin and a slight swelling in the affected area. Sometimes disease is accompanied by common manifestations: subfebrile fever or fever, headache and an increase in the number of leukocytes in the blood. When palpating the affected muscle, painful seals can be determined.
Myositis can develop acutely or have a primary chronic course. The acute form can also turn into a chronic one. This usually occurs in the absence of treatment or with inadequate treatment. Acute myositis occurs after muscle strain, injury or hypothermia. Infectious and toxic myositis are characterized by a gradual onset with less pronounced clinical symptoms and a primary chronic course.
Chronic myositis proceeds in waves. Pain appears or increases with prolonged static loads, weather changes, hypothermia or overstrain. Muscle weakness is noted. It is possible to restrict movement (usually insignificant) in adjacent joints.
Types
Cervical and lumbar myositis
Cervical myositis is the most common of all myositis. It usually develops as a result of a cold, after overexertion of muscles or prolonged stay in an uncomfortable position. It is accompanied by dull pain, which is more often localized only on one side of the neck. Sometimes the pain goes to the back of the head, to the temple, ear, shoulder or the interscapular area. When moving, a patient with myositis spares the neck, movements in the cervical spine may be somewhat limited due to pain.
Lumbar myositis is also quite widespread. Due to the same localization of pain, patients sometimes confuse it with any other, however, the pain in this case is not so acute, mainly of a nagging nature, does not decrease at rest, increases with movements and pressure on the muscles of the affected area.
Cervical myositis and lumbar muscle myositis usually have to be differentiated with an exacerbation of osteochondrosis, and lumbar myositis – also with a hernia of the corresponding spine. When making a diagnosis, pay attention to the nature of pain (aching), increased soreness during palpation of muscles and the presence or absence of neurological symptoms. To clarify the diagnosis, radiography of the spine, MRI of the neck, magnetic resonance imaging of the spine or computed tomography can be performed.
It should be borne in mind that sometimes constant, not too intense aching pain in the lumbar region indicates kidney disease. Therefore, if such pains occur, it is necessary to consult a doctor so that he assesses the clinical symptoms, confirms or excludes the diagnosis of myositis and, if necessary, directs the patient to additional studies (blood and urine analysis, kidney ultrasound, etc.).
Dermatomyositis and polymyositis
Dermatomyositis belongs to a group of systemic connective tissue diseases. It is quite rare – according to foreign researchers, five people per 1 million population are ill. It usually affects children under the age of 15 or people of mature age (50 years and older). In women, it is observed twice as often as in men.
The classic manifestations of such myositis are considered to be typical symptoms from the skin and muscles. There is weakness of the pelvic and shoulder girdle muscles, abdominal muscles and neck flexors. Patients have difficulty getting up from a low chair, climbing stairs, etc. With the progression of dermatomyositis, it becomes difficult for the patient to hold his head. In severe cases, it is possible to damage the swallowing and respiratory muscles with the development of respiratory failure, difficulty swallowing and a change in the timbre of the voice. The pain syndrome in dermatomyositis is not always expressed. There is a decrease in muscle mass. Over time, muscle areas are replaced by connective tissue, tendon-muscle contractures develop.
On the part of the skin, there is a heliotropic rash (red or purple rashes on the eyelids, sometimes on the face, neck and trunk) and a symptom of Gottron (pink or red peeling plaques and nodules on the extensor surface of small and medium joints of the extremities). It is also possible to damage the lungs, heart, joints, gastrointestinal tract and disorders of the endocrine system. About a quarter of patients have manifestations only from the muscles. In this case, the disease is called polymyositis.
The diagnosis is made on the basis of the clinical picture and data from biochemical and immunological blood tests. A muscle biopsy may be performed to confirm the diagnosis. The basis of therapy is glucocorticoids. According to the indications, cytostatic drugs (azathioprine, cyclophosphamide, methotrexate) are used, as well as drugs aimed at maintaining the functions of internal organs, eliminating metabolic disorders, improving microcirculation and preventing the development of complications.
Ossifying myositis
It is not a single disease, but a group of connective tissue diseases. It is characterized by the formation of areas of ossification in the muscles. It may occur as a result of trauma or be congenital, genetically determined. Traumatic ossifying myositis is characterized by a relatively favorable course. Only the muscles and articular ligaments in the area of injury are affected. It is treated surgically. The final result of the operation depends on the localization and extent of the damage.
Progressive ossifying myositis is a hereditary disease. It starts spontaneously, gradually covers all muscle groups. The course of myositis is unpredictable. There is no specific prevention and treatment yet. Death with progressive myositis occurs due to ossification of the swallowing and pectoral muscles. It is extremely rare – 1 case per 2 million people.
Myositis treatment
Doctors of various profiles are engaged in treatment, the choice of a specialist is determined by the cause of the disease. Thus, myositis of parasitic etiology are usually treated by parasitologists, infectious myositis therapists or infectious diseases, traumatic myositis and myositis that developed after significant physical exertion – traumatologists–orthopedists, etc. Therapy of myositis includes pathogenetic and symptomatic measures. In case of bacterial damage, antibiotics are prescribed, in case of parasitic – anthelmintic agents. With myositis resulting from autoimmune disease, long-term courses of immunosuppressants and glucocorticoids are indicated.
In acute myositis and exacerbation of chronic myositis, the patient is recommended bed rest and restriction of physical activity. When the temperature rises, antipyretics are prescribed. Analgesics are used to combat pain syndrome, anti–inflammatory drugs are used to eliminate inflammation, usually from the NSAID group (ketoprofen, ibuprofen, diclofenac, etc.). Warming ointments are effective for local myositis. The local irritating effect of these drugs promotes muscle relaxation and reduces the intensity of the pain syndrome. Massage is also used (contraindicated in purulent myositis), physiotherapy procedures and physical therapy. With purulent myositis, an autopsy and drainage of the purulent focus is performed, antibiotics are prescribed.