苔藓样糠疹的发病率和患病率尚不明确。 在美国,尚没有苔藓样糠疹的患病率报道;估计发病率为 1/2000。[3]Blyumin ML, Khachemoune A. What caused these excoriated papules? Diagnosis: pityriasis lichenoides et varioliformis acuta (PLEVA). Skin and Aging. 2004;12:99-102. 苔藓样糠疹可见于任何年龄、种族和地域的个体。 但男性易感性稍高,且童年晚期和成年早期为易发期。[1]Khachemoune A, Blyumin ML. Pityriasis lichenoides: pathophysiology, classification, and treatment review. Am J Clin Dermatol. 2007;8(1):29-36.http://www.ncbi.nlm.nih.gov/pubmed/17298104?tool=bestpractice.com 有证据表明,患病高峰年龄约在 20~30 岁左右。[4]Bowers S, Warshaw EM. Pityriasis lichenoides and its subtypes. J Am Acad Dermatol. 2006 Oct;55(4):557-72;http://www.ncbi.nlm.nih.gov/pubmed/17010734?tool=bestpractice.com 对于儿童来说,苔藓样糠疹的发生有明显的季节性,以秋、冬季最为多见。[5]Ersoy-Evans S, Greco F, Mancini A, et al. Pityriasis lichenoides in childhood: A retrospective review of 124 patients. J Am Acad Dermatol. 2007 Feb;56(2):205-10.http://www.ncbi.nlm.nih.gov/pubmed/17097385?tool=bestpractice.com