Not An Allergen

LED Light Therapy

The jury is still out on efficacy and long-term effects but LED light therapy (more correctly called photobiomodulation or PBM) is not a top contact allergen.

Should you go out and get a PBM therapy mask or wand? We’d recommend speaking to your dermatologist first. A certain level of power is required for these “cold lasers” to do anything and home devices either tend to have energies that are too low or types of lights that are not proven to be effective (so far, blue, red, and near-infrared seem promising). Gadgets that do have adequate power tend to cost hundreds or thousands of dollars. Plus, the wrong types of lights may be ineffective or harmful.

Is it PBM therapy effective? Is it risky?

There is some research that supports the benefits of PBM but there are still many unknowns including what mix of lights is healthiest and most effective, and what the cumulative effects of this exposure (combined with daily exposure to visible light from phones, computers, and indoor lights) might be on skin photoaging and pigmentation (both hyper- and hypopigmentation). As a recent review on the impact of visible light in skin states, “greater attention must be paid during medical treatments to take into account intensity, dose, exposed area, exposure duration, expose frequency, operation mode, and skin phototype-dependent differences in the pigmentary response of VL.” The researchers conclude:

Like a double-edged sword, VL plays distinct roles in the onset, progression, and treatment in skin pigmentary disorders under different parameters and modes, targeting different skin-phototype individuals. More basic and clinical studies are merited to explore the precise mechanisms of pigment metabolism through VL regulation, which may provide a scientific basis for more effective prevention and management of photo-aggravated pigmentary disorders.

In other words, there are potential benefits but also potential risks and it is still unclear (more research is needed) which types of lights, which mixture of lights, and what intensity and delivery methods work best for different skin conditions and skin phototypes.

Contact dermatitis risk

There is no contact dermatitis risk to the light rays themselves but there are potential contact risks in the gadgets if they have handles or cushioned areas with rubber or foam (or related allergens like thiuram and carba mix); metal parts; plastics with benzophenone; or dyes.

Subscribe to VMVinSKIN.com and our YouTube channel for more hypoallergenic tips and helpful “skinformation”!

If you have a history of sensitive skin…

…don’t guess! Random trial and error can cause more damage. Ask your dermatologist about a patch test.

To shop our selection of hypoallergenic products, visit vmvhypoallergenics.com. Need help? Ask us in the comments section below, or for more privacy (such as when asking us to customize recommendations for you based on your patch test results) contact us by email, or drop us a private message on Facebook.

For more:

• On the prevalence of skin allergies, see Skin Allergies Are More Common Than Ever. 
• For the difference between irritant and allergic reactions, see It’s Complicated: Allergic Versus Irritant Reaction.
• For the difference between food, skin, and other types of reactions: see Skin & Food Allergies Are Not The Same Thing. 
• On the differences between hypoallergenic, natural, and organic, check out Is Natural Hypoallergenic? and this video in our YouTube channel. 
• To learn about the VH-Rating System and hypoallergenicity: What Is The Validated Hypoallergenic Rating System?

Main References: 

Regularly published reports on the most common allergens by the North American Contact Dermatitis Group and European Surveillance System on Contact Allergies (based on over 28,000 patch test results, combined), plus other studies. Remember, we are all individuals — just because an ingredient is not on the most common allergen lists does not mean you cannot be sensitive to it, or that it will not become an allergen. These references, being based on so many patch test results, are a good basis but it is always best to get a patch test yourself.

1. He X, Jin S, et al. The Emerging Role of Visible Light in Melanocyte Biology and Skin Pigmentary Disorders: Friend or Foe? Journal of Clinical Medicine. 2023; 12(23):7488. https://doi.org/10.3390/jcm12237488
2. Worthington, L. (2024, March 28). LED light therapy for skin is trendy—but does it work? National Geographic, https://www.nationalgeographic.com/science/article/led-red-light-mask-cold-laser-treatment
3. DeKoven JG, Silverberg JI, Warshaw EM, Atwater AR, et al. North American Contact Dermatitis Group Patch Test Results: 2017-2018. Dermatitis. 2021 Mar-Apr 01;32(2):111-123.
4. DeKoven JG, Warshaw EM, Zug KA, et al. North American Contact Dermatitis Group Patch Test Results: 2015-2016. Dermatitis. 2018 Nov/Dec;29(6):297-309.
5. DeKoven JG, Warshaw EM, Belsito DV, et al. North American Contact Dermatitis Group Patch Test Results 2013-2014. Dermatitis. 2017 Jan/Feb;28(1):33-46.
6. Warshaw, E.M., Maibach, H.I., Taylor, J.S., et al. North American contact dermatitis group patch test results: 2011-2012. Dermatitis. 2015; 26: 49-59.
7. W Uter et al. The European Baseline Series in 10 European Countries, 2005/2006–Results of the European Surveillance System on Contact Allergies (ESSCA). Contact Dermatitis 61 (1), 31-38.7 2009.
8. Wetter, DA et al. Results of patch testing to personal care product allergens in a standard series and a supplemental cosmetic series: An analysis of 945 patients from the Mayo Clinic Contact Dermatitis Group, 2000-2007. J Am Acad Dermatol. 2010 Nov;63(5):789-98.
9. Warshaw EM, Buonomo M, DeKoven JG, et al. Importance of Supplemental Patch Testing Beyond a Screening Series for Patients With Dermatitis: The North American Contact Dermatitis Group Experience. JAMA Dermatol. 2021 Dec 1;157(12):1456-1465.
10. Verallo-Rowell VM. The validated hypoallergenic cosmetics rating system: its 30-year evolution and effect on the prevalence of cosmetic reactions. Dermatitis 2011 Apr; 22(2):80-97.
11. Ruby Pawankar et al. World Health Organization. White Book on Allergy 2011-2012 Executive Summary.
12. Misery L et al. Sensitive skin in the American population: prevalence, clinical data, and role of the dermatologist. Int J Dermatol. 2011 Aug;50(8):961-7.
13. Warshaw EM1, Maibach HI, Taylor JS, Sasseville D, DeKoven JG, Zirwas MJ, Fransway AF, Mathias CG, Zug KA, DeLeo VA, Fowler JF Jr, Marks JG, Pratt MD, Storrs FJ, Belsito DV. North American contact dermatitis group patch test results: 2011-2012.Dermatitis. 2015 Jan-Feb;26(1):49-59.
14. Warshaw, E et al. Allergic patch test reactions associated with cosmetics: Retrospective analysis of cross-sectional data from the North American Contact Dermatitis Group, 2001-2004. J AmAcadDermatol 2009;60:23-38.
15. Foliaki S et al. Antibiotic use in infancy and symptoms of asthma, rhinoconjunctivitis, and eczema in children 6 and 7 years old: International Study of Asthma and Allergies in Childhood Phase III. J Allergy Clin Immunol. 2009 Nov;124(5):982-9.
16. Kei EF et al. Role of the gut microbiota in defining human health. Expert Rev Anti Infect Ther. 2010 Apr; 8(4): 435–454.
17. Thavagnanam S et al. A meta-analysis of the association between Caesarean section and childhood asthma. Clin Exp Allergy. 2008;38(4):629–633.
18. Marks JG, Belsito DV, DeLeo VA, et al. North American Contact Dermatitis Group patch-test results, 1998 to 2000. Am J Contact Dermat. 2003;14(2):59-62.
19. Warshaw EM, Belsito DV, Taylor JS, et al. North American Contact Dermatitis Group patch test results: 2009 to 2010. Dermatitis. 2013;24(2):50-99.
20. Verallo-Rowell V. M, Katalbas S.S. & Pangasinan J. P. Natural (Mineral, Vegetable, Coconut, Essential) Oils and Contact Dermatitis. Curr Allergy Asthma Rep 16,51 (2016) . https://doi.org/10.1007/s11882-016-0630-9.
21. Park G, Oh DS, Lee MG, Lee CE, Kim YU. 6-Shogaol, an active compound of ginger, alleviates allergic dermatitis-like skin lesions via cytokine inhibition by activating the Nrf2 pathway. Toxicol Appl Pharmacol. 2016 Nov 1;310:51-59. doi: 10.1016/j.taap.2016.08.019. Epub 2016 Aug 22. PMID: 27562088.
22. de Groot AC. Monographs in Contact Allergy, Volume II – Fragrances and Essential Oils. Boca Raton, FL: CRC Press Taylor & Francis Group; 2019.
23. De Groot AC. Monographs in Contact Allergy Volume I. Non-Fragrance Allergens in Cosmetics (Part I and Part 2). Boca Raton, Fl, USA: CRC Press Taylor and Francis Group, 2018.
24. Zhu TH, Suresh R, Warshaw E, et al. The Medical Necessity of Comprehensive Patch Testing. Dermatitis. 2018 May/Jun;29(3):107-111.

Want more great information on contact dermatitis? Check out the American Contact Dermatitis Society, Dermnet New Zealand, the Contact Dermatitis Institute, and your country’s contact dermatitis association.

---