Human scalp irritation compared to that of the arm and back.
Large-scale data comparing reactions to surfactants between scalp and back and arm are lacking. The sensitivity of responses between scalp and back and arm were explored utilizing an open-application model for testing the potential irritancy of sodium lauryl sulphate (SLS). 10 bald male Caucasians (mean age 56 +/- 9 years) were enrolled. We conducted 5 successive washings: for each wash, the technician pipetted 1 ml of 20% SLS solution into a glass cylinder placed on the designated area with hand pressure that prevented the cylinder leaking. The test area was then rubbed with a Teflon Policeman scrubber for 1 min. Post scrubbing, the solution was absorbed dry with a plastic pipette and blotted by gently applying paper tissues. After a 5-min rest, the procedure was repeated for 4 more times for a total of 5 times. Skin-irritancy assessments by visual scoring and instrumental measurements were made at 30 min and 24 h thereafter and squamometry at the end of last washing. Results indicated that most param- eters revealed that the back was most sensitive to the SLS challenge. Thus, these data support the current standard skin-compatibility testing procedure, employing the back for potential irritation testing of hair care products.
Zhai
Hongbo
H
Department of Dermatology, University of California, School of Medicine, San Francisco, CA 94143-0989, USA.
Fautz
Rolf
R
Fuchs
Anne
A
Bhandarkar
Sulochana
S
Maibach
Howard I
HI
D001132:Arm; D001415:Back; D017453:Dermatitis, Irritant / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000379:methods; D012535:Scalp / Q000187:drug effects*; D012680:Sensitivity and Specificity; D012867:Skin / Q000187:drug effects*; D023422:Skin Irritancy Tests / Q000379:methods*; D012967:Sodium Dodecyl Sulfate / Q000008:administration & dosage / Q000009:adverse effects*; D013501:Surface-Active Agents / Q000008:administration & dosage / Q000009:adverse effects*; D013997:Time Factors
D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate