虽然EM相对较常见,但发生率不明。 20至30岁为高发年龄,3岁以下和50岁以上极少发病。 超过20%的病例发生于儿童。 5岁以下儿童病情相对更严重。 男女比例为3:2,至少30%的患者出现复发。[2]Sokumbi O, Wetter DA. Clinical features, diagnosis, and treatment of erythema multiforme: a review for the practicing dermatologist. Int J Dermatol. 2012;51:889-902.http://onlinelibrary.wiley.com/doi/10.1111/j.1365-4632.2011.05348.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/22788803?tool=bestpractice.com[3]French LE, Prins C. Erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis. In: Bolognia JL, Jorizzo JL, Rapini RP, eds. Dermatology. 2nd ed. London, UK: Mosby-Elsevier; 2008:287-300.[4]Bastuji-Garin S, Rzany B, Stern RS, et al. Clinical classification of cases of toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme. Arch Dermatol. 1993;129:92-6.http://www.ncbi.nlm.nih.gov/pubmed/8420497?tool=bestpractice.com[5]Assier H, Bastuji-Garin S, Revuz J, et al. Erythema multiforme with mucous membrane involvement and Stevens-Johnson syndrome are clinically different disorders with distinct causes. Arch Dermatol. 1995;131:539-543.http://www.ncbi.nlm.nih.gov/pubmed/7741539?tool=bestpractice.com 在一项评估 22 例 EM 患者(14 名男性,8 名女性)的回顾性研究中,27% 的患者(6 名)有明确的药物服用史(5 例轻症 EM 分别服用了甲氨蝶呤、安乃静、头孢呋辛、阿莫西林、钡对比剂;1 例重症 EM 服用了环丙沙星),32% 的患者(7 名)出现了伴随的口唇疱疹感染。药物和单纯疱疹病毒诱发的 EM 主要为轻症,症状较轻。多数重症 EM 病例可出现大量水疱,没有明确的病因。[1]Lerch M, Mainetti C, Terziroli Beretta-Piccoli B, Harr T. Current perspectives on erythema multiforme. Clin Rev Allergy Immunol. 2018;54:177-184.http://www.ncbi.nlm.nih.gov/pubmed/29352387?tool=bestpractice.com