Carpal tunnel syndrome associated with eosinophilic fasciitis

Non-allergic Eosinophilic Inflammation

Much is known about the eosinophilic processes associated with antigens, tumors, and infection, yet data on other causes of eosinophilic inflammation are scarce. This paper investigates the locations and causes of other nonrespiratory eosinophilic inflammation. Although eosinophilic inflammation can involve locomotor, urinary, cardiovascular, nervous, gastrointestinal, and other mucosal surfaces, such inflammation also can accompany tissue trauma, foreign-body reactions, and necrotic or granulomatous processes. Despite their cytolytic/histolytic effects, eosinophil leukocytes are a component of tissue remodeling, can be antigen-presenting cells, and have a role in the reproductive system and in blood coagulation. The study of various types of eosinophilic inflammation may increase our understanding of the biological responses of eosinophil leukocytes to different inflammatory stimuli.

Scleroderma-like cutaneous syndromes

Several distinct entities associated with dermal fibrosis can mimic scleroderma/systemic sclerosis. The list of scleroderma-like conditions or scleroderma variants includes eosinophilic fasciitis, localized forms of scleroderma, scleredema and scleromyxedema, keloids, and environmental exposure-associated conditions including eosinophilia-myalgia syndrome and pseudosclerodermas induced by various drugs. Although these conditions are relatively uncommon, their accurate recognition is essential to avoid misdiagnosis and inappropriate therapy. The pathogenesis of these scleroderma variants appears to share similarities with each other and with that of scleroderma. Better understanding of scleroderma-like disorders is emerging through epidemiologic investigations, and in vivo and in vitro experimental research. Activation of eosinophils and disordered regulation of fibroblast collagen synthesis, apoptosis, and proliferation are recurrent findings in these disorders. The etiologic role of infection with Borrelia species or other microorganisms remains controversial. Cytokines such as transforming growth factor-beta, interleukin-4, interleukin-13, and connective tissue growth factor contribute to fibrosis in these disorders by inducing an accentuated and persistent fibrogenic response to tissue injury. The role of genetic factors in susceptibility and clinical expression of scleroderma-like conditions remains to be systematically addressed. Because of the relative rarity of these conditions, few well-controlled clinical treatment trials have been performed. In addition, there is no consensus on optimal management. Much anecdotal information and small clinical series indicate that phototherapy may have a role in the treatment of scleroderma-like conditions.

Eosinophilia and musculoskeletal disease

Eosinophilia is occasionally a feature of rheumatic disease. The differential diagnosis of eosinophilia includes parasitic infection, systemic vasculitides, eosinophilic arthritis, and myopathies, together with the idiopathic hypereosinophilic syndrome and malignancy. Careful evaluation of the patient should enable an accurate diagnosis to be made. Parasitic infection is the commonest cause of eosinophilia worldwide and can cause systemic disease, as illustrated by the report of Sarcocystis myositis in a group of military personnel in Malaysia. A persistent arthropathy associated with eosinophilia, but not with parasitic infection, has been reported from the far East. Drugs may also cause eosinophilia, and there has recently been much discussion of the relation between Churg-Strauss syndrome and the leukotriene antagonist zafirlukast. The present view is that reduction of steroid dose allows unmasking of previously undiagnosed Churg-Strauss syndrome. The idiopathic hypereosinophilic syndrome may represent a lymphoproliferative process; evidence for this comes from the demonstration that many patients have a clonally expanded population of aberrant T cells.