Section 5. Bone, Joint, and Muscle Disorders

Chapter 68. Autoimmune Disorders of Connective Tissue

Topics: Introduction | Systemic Lupus Erythematosus | Scleroderma | Sjögren's Syndrome | Polymyositis and Dermatomyositis | Mixed Connective Tissue Disease | Relapsing Polychondritis | Eosinophilic Fasciitis

Eosinophilic Fasciitis

Eosinophilic fasciitis is a disorder in which the skin of the arms and legs becomes painfully inflamed and swollen and gradually hardens.

The name eosinophilic refers to the initially high blood levels of a type of white blood cell called eosinophils. Fasciitis refers to inflammation of the fascia, which is the tough fibrous tissue that lies beneath the skin.

The cause of eosinophilic fasciitis is unknown. The disorder occurs mainly in men aged 40 to 50, but it may occur in women and children.

Symptoms

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 also. In contrast to scleroderma, the skin of the feet and hands is not affected and Raynaud's phenomenon does not occur.

Symptoms may first be noticed after strenuous physical activity, particularly in a person who usually does not exercise very much. 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 Section 5, Chapter 71).

Sometimes, the numbers of red blood cells and platelets in the bloodstream become very low, resulting in anemia and a tendency to bleed easily.

Diagnosis

A doctor suspects eosinophilic fasciitis because of its typical symptoms. Blood tests are performed to detect increased proteins called globulins. The number of eosinophils (a type of white blood cell) is increased as is the erythrocyte sedimentation rate (ESR); this increase indicates inflammation.

The diagnosis is confirmed by taking and examining under a microscope a small sample (biopsy) of affected skin and the tissues underneath it (the fascia). The biopsy sample must include all skin layers down to the muscle. Magnetic resonance imaging (MRI) can help confirm the diagnosis but is usually unnecessary because the biopsy and other tests are typically sufficient.

Treatment and Prognosis

Most people respond rapidly to high doses of corticosteroids. Treatment should be started as early as possible to prevent scarring, tissue loss (atrophy), and contractures. Corticosteroids may 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. The use of other drugs is experimental for people who cannot use or do not fully respond to corticosteroids.

Although the long-term outlook is unknown, eventually, with or without treatment, the inflammation of eosinophilic fasciitis generally resolves on its own, leaving the scars that appeared before treatment.