While our results showed that anti-IL17A do not have the same protective effect against AU flares as anti-TNF mAb, they are also reassuring with regard to a possible deleterious effect of anti-IL17 without significant difference between anti-IL17 and placebo (OR = 1.38 [CI 95% 0.63–2.99]). This evidence concerns the gene IL17A and alopecia universalis congenita.