Eosinophilic fasciitis is a rare systemic rheumatic disease in which the skin and the tissue that lies beneath the skin quickly become progressively swollen and harden in the arms and legs.
The cause is unknown but may be triggered by environmental factors, illness, or medications.
Symptoms include pain, swelling, and inflammation of the skin and the tissues beneath the skin.
A biopsy is done to remove tissue for examination and testing.
Corticosteroids and sometimes other immunosuppressants are helpful.
The word eosinophilic refers to the initially high blood levels of a type of white blood cell called eosinophils. The word fasciitis refers to inflammation of the fascia, which is the tough fibrous tissue that lies on top of and between the muscles.
The cause of eosinophilic fasciitis is unknown but may be triggered by vigorous exercise or injury, Lyme disease, or exposure to certain medications and substances. Eosinophilic fasciitis may occur in some people who have a blood disorder, such as failure to produce red blood cells (called aplastic anemia), or a cancer of plasma cells in the bone marrow (multiple myeloma).
The disorder occurs mainly in middle-aged men but may occur in women and children.
Symptoms of Eosinophilic Fasciitis
The usual initial symptoms of eosinophilic fasciitis are pain, swelling, and inflammation of the skin, particularly over the inside of the arms and the front of the legs. The skin of the face, chest, and abdomen are rarely affected, and the fingers and toes are not affected.
Symptoms usually progress gradually. After weeks, the inflamed skin begins to harden, eventually acquiring a texture similar to an orange peel. Some people may notice a linear indentation over areas where veins are near the surface of the skin, typically when their arm or leg is elevated.
As the skin gradually hardens, the arms and legs become difficult to move. Eventually, the arms and legs may become permanently frozen in unusual positions (contractures) if the disease is not treated early. Muscle strength does not usually decrease, but muscle and joint pain may occur. Rarely, if the arms are affected, the person may develop carpal tunnel syndrome.
Weight loss and fatigue are common.
Diagnosis of Eosinophilic Fasciitis
Biopsy
Blood tests
The diagnosis of eosinophilic fasciitis is based on all of the information doctors gather, including symptoms, physical examination results, and all test results.
The diagnosis is confirmed by taking a biopsy of affected skin and fascia and testing the samples. The biopsy sample must include all skin layers down to the muscle.
Blood tests are also done. Blood tests show that the number of eosinophils in the blood and the erythrocyte sedimentation rate (ESR) are increased. (The ESR is a test for inflammation and measures the rate at which red blood cells settle to the bottom of a test tube containing blood.) These increases indicate inflammation. Although blood test results can help doctors diagnose eosinophilic fasciitis, they alone cannot confirm a definite diagnosis of eosinophilic fasciitis because sometimes the abnormalities they detect are present in healthy people or in people who have other disorders.
Magnetic resonance imaging (MRI) can also help make the diagnosis but is not as conclusive as biopsy.
Treatment of Eosinophilic Fasciitis
Corticosteroids
Treatment of eosinophilic fasciitis should be started as early as possible to prevent scarring, tissue loss (atrophy), and contractures.
Contractures and carpal tunnel syndrome may need to be treated surgically.
Physical therapy may help decrease and prevent more contractures.
Doctors continue to monitor people by doing blood tests so that, if a blood disorder develops, it can be diagnosed and treated as soon as possible.
People who are receiving immunosuppressants are also given medications to prevent infections such as by the fungus Pneumocystis jirovecii (see prevention of pneumonia in people with a weakened immune system) and vaccines against common infections such as pneumonia, influenza, and COVID-19.
Prognosis for Eosinophilic Fasciitis
The long-term outcome varies, but eosinophilic fasciitis may resolve after prompt treatment.
