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Q1: What is the diagnosis?
The biopsy (see p 716) shows marked thickening of the fascia throughout the subcutaneous compartment associated with a chronic inflammatory infiltrate consisting of lymphocytes and plasma cells. Lymphoid follicle formation is also seen. Scattered eosinophils (arrowed) are noted on higher magnification. There is no vasculitis, panniculitis, or fat necrosis. In view of the tissue eosinophilia and initially raised eosinophil count, the diagnosis is eosinophilic fasciitis. A year after his operation the patient is being managed conservatively. There has been spontaneous resolution of his signs (the affected area now measures 6.5 × 2 cm). His eosinophil count returned to normal within three months of his operation and has remained so since this time.
Q2: What is the pathogenesis of this condition?
Eosinophilic fasciitis is considered to be an immunologically mediated disease. A key point in the history is that approximately half of the patients will describe strenuous physical exertion before development of clinical signs and symptoms. It is hypothesised that such exertion might damage muscle, rendering it antigenic and causing an immune response. Such a response is reflected by the dense chronic inflammatory infiltrate, which may include eosinophils in the early stages of the condition, seen within the fascial compartment. These tissue eosinophils are considered to play a central part in the formation of the fascial fibrosis which is the hallmark of this condition.1
Eosinophilic fasciitis presents in the third to fifth decade of life with stiffness, swelling, and non-pitting oedema of the skin. Primary involvement of the fascia causes retraction of the subcutaneous tissue which is most evident between muscle groups (the “groove sign”) and along the course of veins (“sunken veins”). In an extensive review by Moore and Zuckner,2 the upper limbs were involved in 89% of cases, with characteristic sparing of the hands differentiating it from systemic sclerosis. To our knowledge, only one previous case where the findings have been confined to the abdomen, and where the extremities have not also been involved, has been reported in the literature.3
A peripheral blood eosinophilia is seen in over 90% of cases, often with values greater than 1 × 109/l, but there is no clear correlation between clinical activity of disease and the total count. Occasionally, raised erythrocyte sedimentation rate, raised antinuclear antibodies, and hypergammaglobulinaemia are also seen but these are considered of less diagnostic value compared with the findings on an incisional full thickness biopsy involving skin, fat, and fascia in continuity.4
In view of the fact that eosinophilic fasciitis is considered to be an immunologically mediated disease, the treatment of choice in progressive disease, particularly if there are associated contractures, is prednisolone (40–60 mg daily). Other protocols described in the literature include methotrexate, hydroxychloroquine, cyclosporin, and cimetidine. Evaluation of therapy remains difficult however, as patients often show spontaneous remission over two to five years.5 Follow up of these patients is necessary as haematological malignancies in association with eosinophilic fasciitis have been reported and are associated with a poorer prognosis.
Clinically, our patient presented with a short history of an infiltrative process affecting the connective tissues of the lower abdominal wall. A possible diagnosis was scleroderma, either localised or with visceral involvement. In addition, a neoplastic process, either a primary lesion such as fibrosarcoma or liposarcoma or secondary spread due to invasion by a scirrhous intra-abdominal malignancy necessitated exclusion by exploratory surgery. An image directed needle biopsy could not be performed in view of the negative radiological results. An open surgical procedure was decided upon as it would provide an adequately sized biopsy for intraoperative histological examination. It also gave the surgeon an opportunity to treat any microscopically confirmed tumour at the same time by wide local resection. The final diagnosis of eosinophilic fasciitis is associated with a more favourable prognosis compared with soft tissue tumours and systemic sclerosis. Eosinophilic fasciitis not only responds favourably to systemic therapies, such as corticosteroids, but also may spontaneously resolve, as illustrated by our case.
The association of thickening of the skin and a peripheral blood eosinophilia should raise the possibility of eosinophilic fasciitis
A deep biopsy down to and including fascia is required to establish the diagnosis
Eosinophilic fasciitis can affect sites other than the limbs
Long term prognosis of this condition is often favourable