ing this software, spectroscopic parameters were defined to investigate specifically the hair products used in this study on the skin surface.
These findings indicate that shampoo and conditioner are not totally removed after rinsing, and a significant amount of rinse off hair care products end up on our scalp, forehead, cheek, and upper back. And the residue on the skin from the leave-in styling product actually increased over time, with the greatest amount of residue occurring 2-4 hours after application. We did not measure beyond 2 hours for the rinse-off products and 4 hours for the leave-in products. We did not assess skin areas beyond those referenced.
To our knowledge this is the first report demonstrating that hair care products deposit on specific skin areas (scalp, face, back), and stay on the skin for hours after using them. These findings may explain reports of acne from hair care products which are not commonly tested for comedogenicity and often have ingredients with a high propensity for comedogenicity. People may be bathing in comedogenic ingredients daily via their hair care products without realizing it.
Further research would be useful to demonstrate the other skin areas on which hair care products may deposit, and the full duration that the products stay on the skin.
Given these findings, hair care products should be considered
as a potential contributing factor for acne. In addition, hair care
products should be tested in a similar manner as skin care products,
including with comedogenicity testing and repeat insult
patch testing (RIPT) testing for allergy and irritation.
Iris K Rubin, MD is Founder and Chief Medical Officer of SEEN
Hair Care, Bethesda, MD. Study performed by Samuel Gourion-
Arsiquaud (Ph.D) Director at TRI Princeton.
1. American Academy of Dermatology. Are your hair care products causing breakouts? Available at: https://www.aad.org/hair-care-products. Accessed October 17, 2019.
2. Dermatology News. Smooth hair- an acne-causing epidemic. Available at: https://www.mdedge.com/dermatology/article/108161/acne/smooth-hairacne- causing-epidemic. Accessed October 17, 2019.
3. Plewig G, Fulton JE, Kligman AM. Pomade acne. Arch Dermatol. 1970;101:580-584.