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.