Acne-Prone Skin: Should I Opt for a Dermatological Soap Bar?

In the study by ARENS-CORELL M. & al. (1995), researchers evaluated the impact of an acidic syndet bar (a type of dermatological soap bar formulated for acne-prone skin) against regular soap in 120 adolescents and young adults with mild to moderate levels of acne (I or II). Participants washed their faces twice a day over the period of 3 months. With an average baseline of 13.4 inflammatory lesions, the syndet bar group decreased from an average inflammatory lesion to 10.4 (which appears clinically relevant and suggests a potential benefit), compared with the regular soap group, which increased from 14.6 to 15.3. Symptoms of skin irritation were reported by 40.4% of soap users, while syndet bar users reported it in only 1.8%. This demonstrates better efficacy and intolerance in the maintenance of acne-prone skin with the acidic syndet bar.

In another study, VAROTHAI S. & al. (2015) evaluated the pH values for different types of cleansers that are intended for acne regulation and are available on the market, like lotions, liquids, foams, and scrubs. Cleansers were dissolved to get 5% solutions, and the pH was measured right away using a pH meter while also followed up by indicator strips. The findings authenticated that all acne cleansing bars showed alkaline pH (9.0 – 10.4), except for syndet bars (neutral pH) and one bar for oily skin (acidic pH). The pH of the liquids for acne was recorded to range between 3.0 and 8.0, with most liquid toners being more acidic than bars. Foams are either neutral or slightly alkaline, with only two brands recording normal skin pH (5.4 – 5.9). About 60% of the acne scrubs had an acidic pH, while others showed normal or alkaline pH.

Alkaline soap bars increased skin pH by 1.5 – 2.0 units, disrupting the natural acid mantle of the skin that has a standard pH of 4.5 - 5.5. This could result in an increase in TEWL, and leads to dryness, irritation, and damage to the skin barrier. High pH, also creates an environment favorable for the proliferation of acne-causing bacteria (Cutibacterium acnes). All of these can trigger either worse breakouts or inflammation in people with acne prone skin. In conclusion, alkaline soaps are not advisable to use for acne-prone skin. On the other hand, acidic cleansers did not disturb the skin microbiome to such an extent, lessening the chances of irritation, apart from the fact that they carried antibacterial protection. Liquid cleansers, especially those containing amphoteric and nonionic surfactants, were generally well tolerated due to a lower pH.

From a pathological point of view, none of the present study findings categorically point to the actual benefits to support the assumption that acidic or pH-balanced cleansers would be more suited for acne-prone skin compared to abrasive scrubs and alkaline bars, which could, in fact, pose disadvantages, particularly to skin that is already sensitive and prone to acne. So, if you are looking for a dermatological soap bar to treat acne-prone skin, make sure to choose one labeled as an acidic syndet bar (and others that are specifically formulated for this skin type) and try to avoid alkaline soap bars.