Table 8.

Studies on the effects of acid straighteners and traditional straighteners (hair relaxers).

Author	Study type	Population	Straightener agent	Alterations
Marks et al.,43 2019.	Case-control	n = 286 (n = 43 patients with cicatricial alopecia), (143 patients with non-cicatricial alopecia: control group)	Chemical straightener	Higher frequency of hair straightening in the cicatricial alopecia group (25%) compared to the control group (13%).
				Prior history of straightening in 21% in LPP/FFA group and in 10% of paired controls.
				CCCA: more cumulative exposure to straighteners.

n, Number of patients; F, Female; M, Male.