Prevalence of sensitive skin and its biophysical response in a Mexican population

Table 1 Demographic characteristics of the 246 subjects included in the study n (%)

Mean age in years (range)	31.8 (18-66)
Sex
Male	78 (31.7)
Female	168 (68.3)
Skin phototype
II	6 (2.4)
III	31 (12.6)
IV	87 (35.4)
V	122 (49.6)
Self-diagnosed sensitive skin
Yes	89 (36.2)
No	157 (63.8)

Table 2 Prevalence of sensitive skin by self-diagnosis and response to lactic acid stinging test by age group, sex, and phototype (n = 246) (%)

	Self-diagnosis	Positive	Negative
Age groups (yr)
< 20	16 (44.4)	18 (50.0)	18 (50.0)
21-30	32 (32.0)	49 (49.0)	51 (51.0)
31-40	17 (34.6)	31 (63.2)	18 (36.8)
41-50	15 (40.5)	21 (56.7)	16 (43.2)
> 50	9 (37.5)	9 (37.5)	15 (62.5)
Sex
Male	18 (23.0)	27 (34.6)	51 (65.4)
Female	71 (42.2)	101 (60.1)1	67 (39.9)
Skin phototype
II	6 (100)	6 (100)1	0 (0)
III	16 (51.6)	25 (80.7)1	6 (19.3)
IV	33 (37.9)	48 (55.2)	39 (44.8)
V	34 (27.8)	49 (40.2)	73 (59.8)1
Self-diagnosed sensitive skin
Yes	-	71 (79.7)1	18 (20.3)
No	-	57 (36.3)	100 (63.7)1

¹χ² test, P < 0.05 vs negative group.

Table 3 Biophysical measurements evaluated at onset and within 10 min after lactic acid stinging test

	a axis		TEWL		Capacitance
	Positive	Negative	Positive	Negative	Positive	Negative
Basal	13.4 (11.6-15.2)	13.3 (11.4-15.2)	22.9 (12.5-33.3)	23.9 (8.3-39.5)	92 (30-154)	128 (42-298)
3 min	13.3 (11.7-14.6)	13.9 (11.8-16.0)1	27.5 (14.4-40.6)1	23.7 (14.9-32.5)	281 (70-492)	220 (98-342)
5 min	13.9 (11.7-16.1)	14.4 (12.6-16.2)1	26.0 (13.2-38.8)1	22.4 (13.0-31.8)	239 (92-386)1	179 (64-294)
8 min	14.0 (12.2-15.8)	14.0 (12.2-15.8)	24.9 (12.9-36.9)	23.1 (10.9-35.3)	182 (85-269)	156 (34-278)
10 min	13.7 (11.8-15.6)	14.0 (12.1-15.9)	25.1 (13.4-36.8)	24.4 (11.1-37.7)	168 (97-239)	196 (9-383)

Values are shown by positive and negative results to the test for the a value, transepidermal water loss (TEWL), and capacitance. TEWL was measured in g/m² per minute; a and capacitance are shown in arbitrary units. Numbers indicate mean and standard deviation in parenthesis.

¹Mann-Whitney U test, P < 0.05 vs negative group.