Acne Cosmeceutical Myths

Cosmeceuticals do not produce acne if labeled noncomedogenic and nonacnegenic

Similar to hypoallergenic, noncomedogenic and nonacnegenic are marketing claims carrying no implied regulation ( Fig. 25.1 ). They were also developed to create a new consumer image for cosmetic lines designed to minimize acne. In order to make the claim noncomedogenic, rabbit ear or human comedogenicity testing should be undertaken. Both the animal and the human model are based on the presence of new comedone formation after the exposure of skin to the finished cosmetic. Human testing is considered to be more accurate, but the results are highly dependent on the skill of the contract testing laboratory. Acnegenic claims are based on human use testing and the evaluation of volunteer subjects following product use for an increase in the presence of acne. Many manufacturers, however, make noncomedogenic and nonacnegenic claims based on the safety profiles of the individual ingredients in the formulation. This is inaccurate. Noncomedogenic and nonacnegenic claims should be made based on clinical testing of the finished formulation. The dermatologist should still consider all products labeled noncomedogenic or nonacnegenic as problematic.

Mineral oil is comedogenic

Mineral oil is one of the most common ingredients in skin care products and colored cosmetics ( Fig. 25.2 ). It is a lightweight inexpensive oil that is odorless and tasteless. One of the common concerns regarding the use of mineral oil is its presence on several lists of comedogenic substances. These comedogenic lists were developed many years ago, yet remain frequently quoted in the dermatologic literature. There are several important points to consider. First, there are different grades of mineral oil. There is industrial grade mineral oil, which is used as a machine lubricant, that is not of the purity required for skin application. Cosmetic grade mineral oil is the purest form without contaminants. Industrial grade mineral oil may be comedogenic, but cosmetic grade mineral oil is not. Quality manufacturers only purchase quality products from quality suppliers who guarantee the quality of the materials they provide. I believe that cosmetic grade mineral oil is noncomedogenic and I have never found it to be comedogenic in any of the testing I have performed for the skin care industry.

Sunscreens produce acne

Many patients note the occurrence of ‘breakouts’ following the use of sunscreens. These patients typically present with perifollicular papules and pustules in a random distribution over the face. This eruption appears within 24–48 hours after wearing a facial sunscreen. I have not performed biopsies on patients who develop this problem, but I would like to put forth a hypothesis based on my knowledge of how sunscreens function.

Most of the sunscreens on the market today are based primarily on UVB-absorbing ingredients, such as octyl methoxycinnamate, oxybenzone, homosalate, etc. Many also have UVA-absorbing ingredients, such as avobenzone, titanium dioxide, or zinc oxide, as secondary sunscreens. All of the UVB sunscreens and avobenzone function by transforming UV radiation to heat energy through a process known as resonance delocalization. This heat energy is appreciated by many patients who will state that they do not like wearing sunscreens, since the gels or lotions make them feel hot. In some patients, I believe that the increased sweating induced by the sunscreens accompanied by the warm sunny weather causes increased activity by the eccrine glands. This may cause miliaria rubra that may be magnified by the occlusive nature of the water-resistant, rubproof product. Thus, I believe that much of the problem with sunscreen-induced breakout is the formation of papules or pustules around the eccrine duct ostia without the sebaceous gland involvement that characterizes true acne.