Myositis Flashcards
What is myositis?
Myositis is a disease that makes your immune system attack your muscles.
It causes
- chronic inflammation — swelling that comes and goes over a long time.
Eventually, this inflammation makes your muscles feel increasingly (weak). It can also cause (muscle pain.)
- Myositis usually affects the muscles you use to move, including muscles in your:
Arms and shoulders.
Legs and hips.
Abdomen and spine (your trunk).
What are the types of myositis?
1) Polymyositis.
2) Dermatomyositis.
3) Inclusion body myositis.
Polymyositis :-
- Polymyositis affects multiple muscles at the same time.
- develops gradually over time.
Dermatomyositis :-
- Dermatomyositis is a form of myositis that affects your skin in addition to your muscles.
- It can also increase your risk of developing certain kinds of cancer.
- Gottron papeles (hand)
- Heliotrope rash (face)
Inclusion body myositis :-
- Inclusion body myositis is a degenerative muscle disease. It usually affects people older than 50.
- affect the muscles in your throat (dysphagia).
Symptoms
- Muscle weakness.
- Joint or muscle pain.
- Fatigue.
- Swelling.
- Trouble breathing or swallowing.
- Arrhythmia (if the myositis affects your heart).
What causes myositis?
- Some people with other autoimmune diseases are more likely to develop myositis, including:
- Lupus.
- Rheumatoid arthritis.
- Scleroderma.
- Some people develop myositis after they have a viral infection, including:
- The common cold.
- Influenza (the flu).
- HIV.
Diagnosis and Tests
How is myositis diagnosed?
diagnosis of myositis with a physical exam and tests :-
A) Blood tests.
KC :-
Normal <300 iu/L
Myositis 100–7000 iu/L
Other cause ^ CK :-
- MI
- acute kidney injury
- Rhabdomyolysis
- hard exercise
Elevated (ALT-AST-LDH)
B) autoantibody:-
Anti - jo-1 antibodies
C) MRI (magnetic resonance imaging).
D) EMG (electromyography).
E) muscle biopsy.
Management
A) physiotherapy
B) corticosteroids ( prednisolone)
C) immunosuppressants
D) Intravenous immunoglobulin.
B) Biologic therapy
- Infliximap
- Etanercept
How can miosytis affect the liver
Myositis is a condition characterized by inflammation of the muscles. It primarily affects the skeletal muscles, which are the muscles responsible for movement. While myositis primarily affects the muscles, it is possible for it to have indirect effects on other organs, including the liver.
In some cases, myositis can be associated with autoimmune disorders such as polymyositis or dermatomyositis. These conditions involve an abnormal immune response in which the immune system mistakenly attacks healthy tissues, including the muscles. Autoimmune disorders can also affect other organs, including the liver.
The liver is an important organ involved in various metabolic processes and detoxification. If the immune system is dysregulated due to an autoimmune condition like myositis, it can potentially result in inflammation and damage to the liver cells. However, it’s important to note that liver involvement in myositis is relatively rare.
Liver involvement in myositis can manifest in different ways, including:
- Elevated liver enzymes: In some cases, blood tests may reveal elevated levels of liver enzymes, such as alanine transaminase (ALT) and aspartate transaminase (AST), indicating liver inflammation or damage.
- Hepatitis: Myositis-related autoimmune reactions can cause hepatitis, which is inflammation of the liver. This can result in symptoms such as yellowing of the skin and eyes (jaundice), fatigue, and abdominal pain.
- Primary biliary cirrhosis (PBC): Although rare, myositis has been associated with the development of PBC, a chronic liver disease characterized by inflammation and destruction of the small bile ducts within the liver.
If you suspect liver involvement in the context of myositis, it’s important to consult with a healthcare professional. They can evaluate your symptoms, conduct appropriate tests, and provide a proper diagnosis and treatment plan.
Relation between mayositis and hypothyroidism
There is an established association between myositis and hypothyroidism, particularly a specific form of hypothyroidism called autoimmune thyroid disease or Hashimoto’s thyroiditis. Hashimoto’s thyroiditis is an autoimmune condition in which the immune system mistakenly attacks the thyroid gland, leading to inflammation and impaired thyroid function.
Autoimmune diseases often coexist, meaning that individuals with one autoimmune condition may have an increased risk of developing other autoimmune disorders. Myositis and hypothyroidism are both considered autoimmune diseases, and it is not uncommon for them to occur together or for individuals with myositis to have underlying thyroid dysfunction.
In some cases, myositis and hypothyroidism may share common underlying mechanisms and genetic factors. The exact cause of this association is not fully understood, but it is believed that shared genetic susceptibility and immune dysregulation play a role.
The presence of hypothyroidism in individuals with myositis can have implications for disease management. Hypothyroidism can cause fatigue, muscle weakness, and muscle stiffness, which can overlap with symptoms of myositis. Therefore, it is essential to evaluate and manage thyroid function in individuals with myositis to optimize their overall health.
If you have been diagnosed with myositis or suspect you may have it, and you also have symptoms or concerns related to your thyroid function, it is important to consult with a healthcare professional. They can evaluate your symptoms, order appropriate tests (such as thyroid function tests), and provide appropriate management and treatment for both conditions if necessary.
