Clinical outcomes and 5-year follow-up results of keratosis pilaris treated by a high concentration of glycolic acid

Table 3 Changes in melanin content, skin hemoglobin content, and skin lightness before and after treatment

Measurement index	Pretreatment	Day 20	Day 40	Day 60	Day 80	5 yr
M value	219.48 ± 64.09	215.80 ± 63.87	213.12 ± 60.421	203.92 ± 58.621	197.04 ± 59.231	223.56 ± 45.51
E value	261.76 ± 60.31	256.16 ± 64.00	258.48 ± 67.86	248.36 ± 62.501	242.2 ± 66.391	255.13 ± 51.25
L value	61.41 ± 4.23	61.94 ± 4.17	62.20 ± 3.941	62.57 ± 3.781	63.24 ± 3.601	61.89 ± 3.83

¹P < 0.05 vs pretreatment. E: Skin hemoglobin content; L: Skin lightness; M: Melanin content.