Granulomatous dysimmune reactions (sarcoidosis, granuloma annulare, and others) on differently injured skin areas

摘要: Granulomatous disorders are chronic cell-mediated immune responses histologically characterized by collections of macrophages, epithelioid cells, and multinucleated giant cells. This disease spectrum often has an infectious origin, but sometimes neither infective agent nor inciting antigenic stimulus can be identified. The skin may a preferential target for these disorders, especially in the areas that have been damaged various forms injury (eg, herpetic infections, trauma, thermal or solar burns, vaccinations, tattoos). These sites frame new concept immunocompromised cutaneous district (ICD), which defines area with acquired dysregulation pave way local onset opportunistic such as tumors, granulomatous disorders. Sarcoidosis, granuloma annulare (GA), vasculitis, Churg-Strauss syndrome (CSS) Wegener's granulomatosis (WG), most common occur ICD share pathogenic mechanisms. Recent studies found clinical pathologic overlapping features across noninfectious granulomas. Although no unifying etiology exists, development processes reported literature contains hypotheses to explain it: (1) overactive response previously injured region without loss tolerance; (2) overall reduced response; (3) retention exogeneous antigen foreign body; (4) altered neural signaling; (5) combination all aforementioned processes. T helper regulatory well number proteins, identified potential contributing factors. In addition, genetic predisposition intact systemic system both instrumental persistence formation ICD.