¹WenChieh Chen, ²Chao-Chun Yang, ²Sheau-Chiou Chao, ²Julia Yu-Yun Lee

¹Department of Dermatology, Chang Gung University, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; ²Department of Dermatology, College of Medicine, National Cheng Kung University, Tainan, Taiwan

Objectives: Alopecia areata (AA) is considered to be a T-cell mediated hair follicle-targeted autoimmune disease, affecting 1 % of the general population. Common associated diseases include atopic syndrome, vitiligo, thyroid diseases, diabetes mellitus and Down’s syndrome. Pityriasis lichenoides is a rare cutaneous eruption of unknown cause and infectious agents have long been suspected as etiologic factors. The Renbök phenomenon, or inverse Koebner phenomenon, has been observed in psoriatic patients with AA, in which hair growth was normal in the psoriatic lesions. Cases with AA sparing congenital melanocytic nevi have also been reported.

Methods: Clinical observation and follow-up were performed on two AA patients associated with pityriasis lichenoides et varioliformis acuta (PLEVA) and nevus flammeus, respectively.

Results: The first case was a five-year-old boy who developed AA shortly after the incident of PLEVA. Both diseases seemed to wax and wane simultaneously for one year since their concurrence. The second case was a 30-year-old man presenting with rapidly progressing alopecia universalis, which spared a congenital nevus flammeus on the scalp that retained the ability to grow terminal hair.

Conclusions: Infection might be the common cause inducing PLEVA and AA in our first case. Our second case supports the notion that nevi, as genetic mosaics, show genetically determined resistance to alopecia areata.