Eosinophilic fasciitis is a rare disorder in which the skin and tissue that lies beneath the skin become painfully inflamed and swollen and gradually harden in the arms and legs.
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. The disorder occurs mainly in middle-aged men but may occur in women and children.
The usual initial symptoms 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 may occasionally be affected. In contrast to systemic sclerosis (see Systemic Sclerosis), the fingers and toes are not affected and Raynaud phenomenon does not occur.
Symptoms may first be noticed after strenuous physical activity. Symptoms usually progress gradually. After weeks, the inflamed skin begins to harden, eventually acquiring a texture similar to an orange peel.
As the skin gradually hardens, the arms and legs become difficult to move. Eventually, the arms and legs may become stuck in unusual positions. Weight loss and fatigue are common. Muscle strength does not usually decrease, but muscle and joint pain may occur. Rarely, if the arms are involved, the person may develop carpal tunnel syndrome (see Carpal Tunnel Syndrome).
Sometimes, the numbers of red blood cells and platelets in the bloodstream become very low, resulting in fatigue and a tendency to bleed easily. Occasionally, the person develops a blood disorder, such as failure to produce red blood cells (called aplastic anemia), a low number of platelets (which help blood clot) that causes bleeding, or lymphoma.
A doctor suspects eosinophilic fasciitis because of its typical symptoms. The number of eosinophils is increased in the blood, as is the erythrocyte sedimentation rate (ESR). This increase indicates inflammation.
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. Magnetic resonance imaging (MRI) can also help make the diagnosis but is not as conclusive as muscle biopsy.
The long-term outcome varies, but eosinophilic fasciitis may resolve after treatment.
Most people respond rapidly to high doses of corticosteroids (such as prednisone). Treatment should be started as early as possible to prevent scarring, tissue loss (atrophy), and contractures. Corticosteroids do not reverse atrophied and scarred tissue. Doses are gradually reduced, but corticosteroids may need to be continued at low levels for 2 to 5 years. Some people need corticosteroids for long periods and possibly other drugs (for example, hydroxychloroquine or the immunosuppressants methotrexate, azathioprine, rituximab, mycophenolate mofetil, or cyclosporine). People may also be given nonsteroidal anti-inflammatory drugs (NSAIDs—see see Nonopioid Analgesics : Nonsteroidal Anti-Inflammatory Drugs) and histamine-2 blockers.
Contractures and carpal tunnel syndrome may need to be treated surgically.
Monitoring with blood tests is advised 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 drugs to prevent infections such as by Pneumocystis jirovecii.