It is well established that the mast cell is the primary effector cell in urticaria, but the mechanism of its skin-specific activation should be elucidated to understand the pathogenesis of urticaria. Cutaneous mast cells, but not those from other sites, are selectively activated by C5a and substance P (SP). We observed the spontaneous release of SP in skin chambers attached on skin of patients with severe chronic urticaria. In vitro stimulation of skin slices with SP revealed heterogeneity among the skin donors. Some released LTB4, TNFα, and histamine; Others released LTB4 or TNFα and histamine or histamine alone. Such heterogeneity may account for the cell infiltration observed in some cases of chronic urticaria. Recent work has revealed that about one third of patients with urticaria have circulating histamine-releasing autoantibodies against the high affinity IgE receptor (FcεRI) and, less commonly, against IgE (“autoimmune urticaria”). HLA analysis has suggested the presence of a genetic diathesis for this subgroup of urticaria, but neither clinical nor histopathological investigations distinguished this subgroup from the other. Cysteinyl leukotriene receptor antagonists, such as montelukast and zafirlukast, have been reported to be effective for treating patients that did not respond to histamine receptor antagonists, but others have reported no effect with these drugs. For patients with autoimmune urticaria, the effectiveness of immunosuppressive therapies, such as cyclosporin, intravenous immunoglobulin, and plasmapherasis, have been reported in parallel with the reduction of circulating autoantibodies.
59歳，男性に発症した再発性多発性軟骨炎の1例を報告した．両耳介の腫脹と鞍鼻に加え，気管から気管支にかけての狭窄により呼吸困難を来たし，気管狭窄部にステント留置して呼吸困難を改善し得た．検査所見では白血球増加，抗核抗体陰性，リウマチ因子陰性，抗Type II collagen抗体624倍強陽性を示した．抗Type II collagen抗体価は病勢に一致して変動しプレドニゾロン内服治療により低下した．耳介の病理組織像はリンパ球，好中球主体の稠密な炎症細胞浸潤をみとめた．自験例は耳介の発赤，腫脹を主訴に最初に皮膚科を受診した例である．しかし，皮膚科領域での報告はあまり多くない．本症は皮疹の他，多彩な軟骨炎症状を示すことから皮膚科，耳鼻科，整形外科，呼吸器内科など関連各科の連携による総合的治療が必要と思われた．さらに，本症の予後因子として鼻腔，咽頭，気管の狭窄が重要であることを銘記すべきと考えた．