Eosinophilic fasciitis: symptoms, diagnosis and treatment

Eosinophilic fasciitis (EF) is a rare condition in which the skin and the tissue beneath it quickly become swollen and then harden, mainly in the arms and legs. The word eosinophilic refers to the initially high blood levels of a type of white blood cell called eosinophils, and fasciitis means inflammation of the fascia, the tough fibrous tissue that lies on top of and between the muscles.

The PCDS UK guidance calls it a rare scleroderma-like condition characterised by an acute presentation of pain, swelling and tenderness of the distal limbs, progressing to fibrosis that can reduce mobility of the hands, feet and other joints. It is not the same condition as scleroderma, but it can look similar.

PCDS says it may occur at any age, although most cases arise between the ages of 30 and 60 years, and that females and males are equally affected. The MSD Manual says it occurs mainly in middle-aged men but may occur in women and children, so reports differ.

PCDS describes an acute, painful onset, with malaise, weakness and fever frequently present. The skin changes occur in three stages. In the first, there is a symmetric, diffuse, reddened tenderness of the distal limbs. The skin then becomes swollen with a characteristic orange-peel appearance. In the final phase there is fibrotic change, with areas of lighter skin colour, hardening and tightness of the ankles and wrists.

In severely affected people both the skin and the subcutaneous tissues are bound down to the underlying muscle, with a woody look, and joint contractures can involve the knees, elbows and shoulders. The MSD Manual adds that some people notice a linear indentation over surface veins when an arm or leg is raised, that muscle strength does not usually fall, and that weight loss and fatigue are common.

Other features that are sometimes reported are carpal tunnel syndrome and inflammatory arthritis. If the arms and legs become difficult to move, the MSD Manual says they may become permanently fixed in unusual positions (contractures) if the disease is not treated early.

Diagnosis is based on the whole picture. PCDS says a full blood count shows raised eosinophils in 70% of cases and that some patients have a raised ESR and hyperglobulinaemia. However, the MSD Manual cautions that blood tests alone cannot confirm the diagnosis, because such abnormalities can occur in healthy people or in people with other disorders.

The key test is a biopsy. PCDS says a full-thickness skin biopsy that includes the dermis, subcutaneous fat and fascia is necessary to confirm the diagnosis, and it shows thickening of the fascia with inflammatory cells including lymphocytes and eosinophils. If clinically indicated, MRI of the involved areas shows a high-intensity signal in the fascia, though the MSD Manual says MRI is not as conclusive as biopsy.

It is important to distinguish it from similar conditions. PCDS points out that in systemic sclerosis, Raynaud’s phenomenon, abnormal nailfold capillaries and sclerodactyly are present, whereas they are absent in EF, and that pansclerotic morphoea has a more insidious onset.

The MSD Manual says treatment should be started as early as possible to prevent scarring, tissue loss and contractures. PCDS says oral corticosteroids are the mainstay, with most patients responding well to moderate-to-high doses, particularly if started early, and that maintenance low-dose treatment may be required for 2 to 5 years.

The MSD Manual says doctors continue to monitor people with blood tests so that, if a blood disorder develops, it can be diagnosed and treated promptly, since EF can occur in people with blood disorders such as aplastic anaemia or multiple myeloma. People on immunosuppressants are also given medicines to prevent infections and vaccines against common infections.

The MSD Manual states that corticosteroids do not cure tissue that is already atrophied and scarred, which is why early recognition matters. Outlook varies: PCDS says in some cases the disease resolves spontaneously, and the MSD Manual says it may resolve after prompt treatment.

See a GP promptly if you develop painful swelling of the forearms or legs with skin that feels thickened or tight, especially after unusual exertion, or if you notice reduced movement at the wrists, ankles or knees. Mention any recent heavy exercise, injury, tick bite or new medicine. Early referral to rheumatology or dermatology matters because treatment works best early.

Sudden severe pain, spreading redness with fever, or loss of feeling in the hands should be assessed urgently through NHS 111 or your GP.

Because EF is rare, diagnosis often involves a rheumatologist or dermatologist and a deep skin biopsy, usually via a GP referral. Some people choose a private specialist to shorten the wait for a first appointment. Whichever route you use, ask which team will oversee long-term steroid monitoring and who to contact if symptoms change.