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Liquid synthetic detergents are more likely to be acidic than other cleansers, making them a good option for people with atopic dermatitis, according to new findings.¹

These findings, to be presented at the 2024 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting, were the results of new research assessing the impact of liquid synthetic detergents on eczema, as well as the use of labeling of such detergents

Adil Khan, MD, the primary author of this new study, described the overwhelming array of options available to consumers when seeking skin cleansers designed for the purpose of improving the atopic dermatitis conditions.

"Shopping for skin cleanser products for atopic dermatitis can be dizzying with so many options available and different claims made on the labels," Khan said in a statement. "Manufacturers that choose to disclose a products' pH on the label can help narrow the choices. In particular, liquid synthetic cleansers most closely mimic normal skin pH."

Khan’s emphasis on the value of manufacturer disclosure of the pH of cleaning products to allow for informed purchasing choices reflects the findings of his team regarding pH variations in the wide variety of such products. The investigators had assessed pH variations in 250 cleansing products which had been sourced from local retail outlets in a medium-sized city in the US.

An Accumet pH meter had been implemented by the research team to assess the pH levels of the different products evaluated in the study. The team formulated solutions through the diluting of liquid products or the extracting of bar soap scrapings in distilled water.

The investigators determined, for the purposes of their research, that a pH range of 6.65 - 7.35 would be considered in their results to be a neutral pH. In their assessment of the 250 cleansing products, the research team found that there were 37 soaps, with 32 bar soaps and 5 liquid soaps, specifically.

Notable Findings

The team also noted that the majority of the products they examined, specifically 213 of the 250 products, were noted as synthetic detergents or ‘syndets.’ They comprised 14 bar syndets and 199 liquid syndets.

Overall, the investigators found that all of the soaps they evaluated had alkaline pH levels, but despite this fact, none of their labels gave information related to a product’s pH. The team reported that among the syndet bars, only a minority that had a PH considered to be neutral, and the majority were labeled as alkaline.

Conversely, the investigators noted that a major proportion of the syndet liquids were shown to be acidic. They specifically found that only a fraction of these products had displayed pH levels through labeling.

Only 12.8% of the cleansers that the research team assessed were shown to have revealed the pH levels of their products. The team noted a wide variation of pH values over the different product brands, adding that all soap products had pH levels which would be considered to be unfavorable.

They added that the majority of the liquid syndets they had assessed were shown to be acidic. The investigators’ findings, overall, emphasize the possible value of liquid syndets for patients with atopic dermatitis.

Khan and colleagues’ research suggests there could be value in the inclusion of pH information on different product labels to allow for more informed decisions for consumers and healthcare providers.

This study contributes to the growing body of research exploring the previously-unexamined harms which may come from incorrect or misleading labeling of personal care products (PCPs), leading to the breakdown of the skin’s defenses. A 2022 feature article published in HCPLive highlighted such findings.²

Related Findings

Peter A. Young, MPAS, and colleagues from the Department of Dermatology at Stanford University, published a study regarding the prevalence of contact allergens found in PCPs.

“Skincare products are not food and they’re not drugs, and so they’re not really regulated by the Food and Drug Administration in our country,” Peter A. Young, MPAS, of the department of dermatology at Stanford University, said in a statement. “Because of that, companies can put a lot of things on the label that aren’t necessarily subject to a rigorous screening process or a rigorous governing process.”

Young’s team had identified 1555 PCPs sold at stores such as Target, Whole Foods Market, and Walgreens, and implemented the Contact Allergy Management Program (CAMP) database to assess the PCPs labeled as ‘natural.’ The team was able to identify a total of 73 unique allergens and found that botanical extracts—known to be a significant cause of contact dermatitis and photosensitization—had been labeled in a somewhat misleading manner.

Young’s findings and those of Khan’s team contribute to a growing awareness among those in the dermatology field that labeling of products may require additional consideration to address the needs of those with atopic dermatitis, contact dermatitis, and similar skin conditions.

References

1. ^{PH Labelling of Skin Cleansers Can Lead to Better Options for People with Atopic Dermatitis. The American Academy of Allergy, Asthma & Immunology (AAAAI). February 20, 2024. https://www.prweb.com/releases/ph-labelling-of-skin-cleansers-can-lead-to-better-options-for-people-with-atopic-dermatitis-302066157.html#:~:text=%22Manufacturers%20that%20choose%20to%20disclose,closely%20mimic%20normal%20skin%20pH.%22&text=Skin%20with%20atopic%20dermatitis%20(AD,contributes%20to%20skin%2Dbarrier%20dysfunction. Date accessed: February 20, 2024.}
2. ^{Smith T. Allergic Contact Dermatitis: Maintaining Our Armor in 2022. HCPLive. December 28, 2022. https://www.hcplive.com/view/allergic-contact-dermatitis-maintaining-armor-2022. Date accessed: February 20, 2024.}