玫瑰糠疹 (PR) 的病因在数十年的研究后仍不明。但是,已可明确排除下列感染原:人类疱疹病毒 (HHV)-8、CMV、EBV、细小病毒 B19、微小核糖核酸病毒、流感病毒、副流感病毒、衣原体、军团病杆菌和支原体。[4]Chuh A, Lee A, Zawar V, et al. Pityriasis rosea - an update. Indian J Dermatol Venereol Leprol. 2005;71:311-315.http://www.ijdvl.com/article.asp?issn=0378-6323;year=2005;volume=71;issue=5;spage=311;epage=315;aulast=Chuhhttp://www.ncbi.nlm.nih.gov/pubmed/16394453?tool=bestpractice.com[9]Chuh A, Chan H, Zawar V. Pityriasis rosea - evidence for and against an infectious aetiology. Epidemiol Infect. 2004;132:381-390.http://www.ncbi.nlm.nih.gov/pubmed/15188706?tool=bestpractice.com没有充足的证据证实 HHV-6 或 HHV-7 是致病原。[8]Deng Y, Li H, Chen X. Palmoplantar pityriasis rosea: two case reports. J Eur Acad Dermatol Venereol. 2007;21:406-407.http://www.ncbi.nlm.nih.gov/pubmed/17309476?tool=bestpractice.com[9]Chuh A, Chan H, Zawar V. Pityriasis rosea - evidence for and against an infectious aetiology. Epidemiol Infect. 2004;132:381-390.http://www.ncbi.nlm.nih.gov/pubmed/15188706?tool=bestpractice.com[12]Yildirim M, Aridogan BC, Baysal V, et al. The role of human herpes virus 6 and 7 in the pathogenesis of pityriasis rosea. Int J Clin Pract. 2004;58:119-121.http://www.ncbi.nlm.nih.gov/pubmed/15055857?tool=bestpractice.com反对感染病因的争论包括不能识别病原体、缺乏真实的流行病学数据,以及对各种在研的抗病毒和大环内酯治疗的疗效不一致。[9]Chuh A, Chan H, Zawar V. Pityriasis rosea - evidence for and against an infectious aetiology. Epidemiol Infect. 2004;132:381-390.http://www.ncbi.nlm.nih.gov/pubmed/15188706?tool=bestpractice.com[13]Amer A, Fischer H. Azithromycin does not cure pityriasis rosea. Pediatrics. 2006;117:1702-1705.http://www.ncbi.nlm.nih.gov/pubmed/16651327?tool=bestpractice.comPR 与特应性病史没有关联。[4]Chuh A, Lee A, Zawar V, et al. Pityriasis rosea - an update. Indian J Dermatol Venereol Leprol. 2005;71:311-315.http://www.ijdvl.com/article.asp?issn=0378-6323;year=2005;volume=71;issue=5;spage=311;epage=315;aulast=Chuhhttp://www.ncbi.nlm.nih.gov/pubmed/16394453?tool=bestpractice.com[8]Deng Y, Li H, Chen X. Palmoplantar pityriasis rosea: two case reports. J Eur Acad Dermatol Venereol. 2007;21:406-407.http://www.ncbi.nlm.nih.gov/pubmed/17309476?tool=bestpractice.com现在仍不清楚自身免疫是否发挥作用,但据报道,PR 患者更易出现抗核抗体阳性。[4]Chuh A, Lee A, Zawar V, et al. Pityriasis rosea - an update. Indian J Dermatol Venereol Leprol. 2005;71:311-315.http://www.ijdvl.com/article.asp?issn=0378-6323;year=2005;volume=71;issue=5;spage=311;epage=315;aulast=Chuhhttp://www.ncbi.nlm.nih.gov/pubmed/16394453?tool=bestpractice.com[8]Deng Y, Li H, Chen X. Palmoplantar pityriasis rosea: two case reports. J Eur Acad Dermatol Venereol. 2007;21:406-407.http://www.ncbi.nlm.nih.gov/pubmed/17309476?tool=bestpractice.com