SELF-PERCEPTION OF SENSITIVE SKIN 269 Lactic Acid 1) Subjects are to be seated in an upright position facing the technician. 2) Wipe the nasolabial fold and adjacent cheek area with a dry cotton pad. 3) Dip a clean cotton-tipped applicator in a container containing 10% aqueous lactic acid. 4) Briskly/gently rub the nasolabial fold/cheek area with the saturated cotton-tipped applicator for 10 seconds. 5) Set a timer for 10 minutes immediately following the application and ask the subject if she is experiencing any sensation and to describe the sensation, if any. 6) The subject will be asked each minute thereafter to grade the test site until the ten minutes has expired. 7) At the end of the 10 minutes, the test site is wiped with a cotton pad moistened with distilled water. 10% Balsam of Peru 1) Subjects are to be seated in an upright position facing the technician. 2) Wipe the cheek area adjacent to the nasolabial fold with a dry cotton pad. 3) Pipette 0.1cc of 10% Balsam of Peru probe on the test site. 4) Rub in the Balsam of Peru for ten seconds with a glass rod using a circular motion over an area the size of a dime. 5) Set a timer for 10 minutes immediately following the application and ask the subject if she is experiencing any sensation and to describe the sensation, if any. 6) The subject will be asked each minute thereafter to grade the test site until the ten minutes has expired. 7) If the subject experiences a sensation of 3 (severe), the solution is removed and the time and grade are recorded. 8) At the end of the 10 minutes, remove the Balsam of Peru using a cotton pad moistened with distilled water. 10:90 Chloroform/Methanol 1) Subjects are to be seated in an upright position with head slightly tilted back to create a level surface or subject may lay down on her back. 2) Wipe the malar eminence of the cheek area (apple of the cheek) with a dry cotton pad. 3) Make a shallow circular well, 8 mm in diameter, on the test site by gently pressing the skin with the end of a plastic cylinder previously dipped in a layer of stopcock grease. The grease forms the wall of the well. 4) Pipette 20gl of the chloroform/methanol solution into the well. 5) Immediately after filling the well with the chloroform/methanol, place a plastic disc over the well to seal. Set the timer for 5 minutes once the disc is in place. 6) Once the solution is placed in the grease ring, ask the subject if she is experiencing any sensation and to describe the sensation, if any. 7) The subject will be asked every 15 seconds thereafter to grade the test site until the five minutes has expired. 8) If at any time the subject experiences a sensation of 3 (severe), the solution is removed and the time and grade are recorded. 9) At the end of the 5 minutes or subsequent to a grade 3 sensation, remove the grease well using a dry cotton pad and wipe the area with a cotton pad moistened with distilled water. Figure 1. RESULTS Of the 1017 subjects enrolled, 405 indicated they had sensitive skin 612 did not. 1017 subjects completed the lactic acid test, 1001 subjects completed the balsam of Peru test, and 889 subjects completed the chloroform methanol test. CLASSIFICATION OF SENSITIVITY A breakdown of the sensitive skin subjects' responses to the questionnaire yielded the following data: © 42% indicated that skin care products caused burning, stinging, or itching. © 30% indicated products caused blackheads, whiteheads, or ache breakouts. © 25% indicated that products caused rashes. © 56% reported that dry cold winter weather exacerbated sensory symptoms. © 14% reported irritation of facial skin due to physical stimulation. COMPARATIVE ANALYSIS OF BUYING PATTERNS 80% of the sensitive skin subjects purchased products labeled for sensitive skin.

270 JOURNAL OF COSMETIC SCIENCE 25% of the non-sensitive skin group purchased products appropriate for sensitive skin. NEUROSENSORY RESPONSES With each probe, the time to onset was statistically significantly less in the sensitive skin group lactic acid stinging revealed the greatest difference between the two groups (see Figure 2). With each of the three probes, peak intensity was statistically significantly greater in the sensitive skin group (see Figure 3). Time to peak response (Table I) was statistically different for the balsam of Peru (30 seconds difference) and lactic acid (90 seconds difference) probes however, for the chloroform/methanol group the difference was less than 15 seconds on average and not statistically significantly different. The grade at onset of reaction (Table I) was higher for the sensitive skin group for each probe, but was significantly different only for the balsam of Peru and lactic acid groups. NON-RESPONDERS There were significant numbers of subjects who did not respond to any of the probes. Of particular interest is the number of sensitives who were non-sensitive (see Figure 4). OTHER OBSERVATIONS Selected demographic information noted an equal number of smokers in each group (approximately 24%). A higher percentage of the self-perceived sensitive skin group indicated having allergies (37% vs 19%) and being flushers/blushers (66% vs 40%). The self-perceived group had a slightly higher percentage of subjects with combination 10:00 Time to Onset - Burning/Stinging 8:00- 6:00- 4:00. 2:00- 0:00- 5:06 6:13 6:00 4:20 1:34 1:08 BP LA CHLOR ß Sensitive [] Non-Sensitive Figure 2. Time to onset of burning/stinging.