Antisynthetase syndrome is a chronic autoimmune disease of unknown cause. It is a subgroup of the idiopathic (unknown cause) inflammatory muscle diseases and is characterized by myositis, interstitial lung disease, arthritis, and Raynaud's phenomenon.
Interstitial (in-tur-STISH-ul) lung disease actually describes a group of disorders, most of which cause progressive scarring of lung tissue. This eventually affects your ability to breathe and get enough oxygen into your bloodstream. Beyond this, the disorders vary greatly.
Most cases of interstitial lung disease develop gradually, but some come on suddenly. Doctors can pinpoint why some cases of interstitial lung disease occur, but many have no known cause.
In all cases, once lung scarring occurs, it's generally irreversible. Medications occasionally can slow the damage of interstitial lung disease, but many people never regain full use of their lungs. Researchers hope that newer drugs, many still experimental, may eventually prove more effective in treating interstitial lung disease.
Signs and symptoms of the wide variety of disorders classified as interstitial lung disease may include:
- A feeling of breathlessness (dyspnea), especially during or after physical activity
- A dry cough
- Chest pain
- Fingernails that curve over the tops of your fingertips (clubbing)
Breathlessness and a dry cough are often the primary signs and symptoms. Because these problems are vague and tend to develop gradually — often long after you have irreversible lung damage — you may assume they are due to aging, asthma, being overweight or out of shape, smoking, or the lingering effects of an upper respiratory infection.
Symptoms tend to become progressively worse. Eventually you may notice you're getting out of breath during routine activities — getting dressed, talking on the phone, even eating. At this point, breathing problems become impossible to ignore. Scar tissue formation in your lungs can lead to a series of life-threatening complications, including:
Low blood oxygen levels (hypoxemia). Because interstitial lung disease reduces the amount of oxygen you take in and the amount that enters your bloodstream, you're likely to develop lower than normal blood oxygen levels. Lack of oxygen can severely disrupt your body's basic functioning.
High blood pressure in your lungs (pulmonary hypertension). Unlike systemic high blood pressure, this condition affects only the arteries in your lungs. It begins when scar tissue restricts the smallest blood vessels, limiting blood flow in your lungs. This in turn raises pressure within the pulmonary arteries. Pulmonary hypertension is a serious illness that becomes progressively worse.
Right-sided heart failure (cor pulmonale). This serious condition occurs when your heart's lower right chamber (right ventricle) — which is less muscular than the left — has to pump harder than usual to move blood through obstructed pulmonary arteries. Eventually the right ventricle fails from the extra strain.
Respiratory failure. In the end stage of chronic interstitial lung disease, respiratory failure occurs when severely low blood oxygen levels along with rising pressures in the pulmonary arteries cause heart failure.
Picture of scarring on lungs from ILD
Raynaud's disease is a condition that causes some areas of your body — such as your fingers, toes, tip of your nose and your ears — to feel numb and cool in response to cold temperatures or stress. In Raynaud's disease, smaller arteries that supply blood to your skin narrow, limiting blood circulation to affected areas.
Women are more likely to have Raynaud's disease. It's also more common in people who live in colder climates.
Treatment of Raynaud's disease depends on its severity and the presence of associated conditions. For most people, Raynaud's disease is more a nuisance than a disability.
Picture of Raynaud's disease
Less common types of arthritis may be associated with conditions that also affect other parts of your body. For example, lupus can affect the kidneys and lungs, in addition to joints, while psoriasis is primarily a skin disease that sometimes also affects joints.
Dermatomyositis (dur-muh-to-mi-uh-SI-tis) is an uncommon inflammatory disease marked by muscle weakness and a distinctive skin rash.
Dermatomyositis may occur at any age, but it mostly affects adults in their late 40s to early 60s, or children between 5 and 15 years of age. Dermatomyositis affects more women than men. The signs and symptoms of dermatomyositis usually develop gradually, over weeks or months.
Periods of remission, when symptoms of dermatomyositis improve spontaneously, may occur. Treatment can clear the skin rash and help you regain muscle strength and function.
The most common signs and symptoms of dermatomyositis include:
A violet-colored or dusky red rash, most commonly on your face, eyelids, and areas around your nails, knuckles, elbows, knees, chest and back. The rash, which can be patchy with bluish-purple discolorations, is often the first sign of dermatomyositis.
Progressive muscle weakness, particularly in the muscles closest to the trunk, such as those in your hips, thighs, shoulders, upper arms and neck. The weakness is symmetrical, affecting both the left and right sides of your body, and tends to gradually worsen.
Other dermatomyositis signs and symptoms that may occur include:
- Difficulty swallowing (dysphagia)
- Muscle pain or tenderness
- Fatigue, fever and weight loss
- Hardened deposits of calcium under the skin (calcinosis), especially in children
- Gastrointestinal ulcers and intestinal perforations, also more common in children
- Lung problems
Possible complications of dermatomyositis include:
Muscle weakness complications
Difficulty swallowing. If the muscles in your esophagus are affected, you may have problems swallowing (dysphagia), which in turn may cause weight loss and malnutrition.
Aspiration and pneumonia. Difficulty swallowing may also lead to entrance of food or liquids, including saliva, into your lungs (aspiration), which can lead to pneumonia.
Breathing problems. If your chest muscles are affected by the disease, you may experience breathing problems, such as shortness of breath.
Gastrointestinal problems. Gastrointestinal ulceration and bleeding can occur.
Skin symptom complications
Calcium deposits. Late in the disease, deposits of calcium can occur in your muscles, skin and connective tissues (calcinosis). These deposits develop earlier and are more common in children with dermatomyositis.
Infections. Dermatomyositis puts you at increased risk of infections, particularly of the respiratory and digestive tracts.
Dermatomyositis may cause other conditions, or put you at higher risk of developing them. These conditions include:
Raynaud's phenomenon. This is a condition in which your fingers, toes, cheeks, nose and ears turn pale when exposed to cold temperatures.
Other connective tissue diseases. Other conditions such as lupus, rheumatoid arthritis, scleroderma and Sjogren's syndrome can occur in combination with dermatomyositis.
Cardiovascular disease. Dermatomyositis may cause the muscle of your heart to become inflamed (myocarditis). In a small number of people who have dermatomyositis, congestive heart failure and heart arrhythmias may develop.
Lung disease. A condition called interstitial lung disease may occur with dermatomyositis. Interstitial lung disease refers to a group of disorders that cause scarring (fibrosis) of lung tissue, making lungs stiff and inelastic. Signs and symptoms include a dry cough and shortness of breath.
Cancer. Dermatomyositis in adults has been linked to an increased likelihood of cancer, particularly of the cervix, lungs, pancreas, breasts, ovaries and gastrointestinal tract. Risk of cancer increases with age, although it appears to level off three years or so after a diagnosis of dermatomyositis. The diagnosis of cancer may also happen before you develop dermatomyositis.
**All information taken from mayoclinic.com