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SUMMARY POINTS
What’s Important
Contact dermatitis, including irritant and allergic variants, affects up to 20% of the population at some point in their life. Personal hygiene and cosmetic products are the culprits behind the majority of the non-occupational cases of contact dermatitis involving the face, neck and hands.
Allergic Contact Dermatitis (ACD) can develop to a chemical ingredient in a product that has been in routine use for years. The cutaneous response of ACD, with erythema, scale and pruritus, can extend beyond the area of direct contact with the allergen.
Fragrances and preservatives are common agents causing ACD. Package labeling of “fragrance free” may mislead the consumer, if the manufacturer includes the fragrance-based ingredient for a non-fragrance function, eg: as a preservative.
Essential oils are the building blocks of fragrances. Natural is not synonymous with safe.
What’s New
Methylisothiozolinone (MI) overtook formaldehyde-releasing preservatives and fragrances as the leading prevalent sensitizing allergen. Moreover, MI was found to be the most clinically relevant allergen, with the highest ever recorded relevance value.
Dillarstone effect describes the development of new contact dermatitis epidemics following 2–3 years after introduction of an allergenic compound to the market.
Although cautioned by the media, parabens are consistently found to be weak sensitizers and play a very minor role in ACD. Moreover, epidemiologic data has failed to show a direct connection between parabens and hormonal effects or the development of breast cancer.
What’s Coming
The COVID-19 pandemic dampened, but saw a rise in index cases of ACD associated with personal protective equipment (masks, gloves and hand sanitizers) both in the health care industry and the public realm.
Open dialogue between consumers and industry members on social media has sparked a movement toward more “clean,” ethically transparent, allergen-free cosmetics which may be the focus of the next decade.
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OVERVIEW OF CONTACT DERMATITIS
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Contact dermatitis (CD) comprises a group of cutaneous reactions that are triggered by the epidermis coming into contact with an allergen or an irritant. There are three main clinical forms of CD: (1) irritant contact dermatitis (ICD); (2) contact urticaria (CU); and (3) allergic contact dermatitis (ACD). CD is highly prevalent and is estimated to affect approximately 15–20% of the general population1 and cost over $1.5 billion in medical expenditure in the United States alone.2 CD clinically presents with debilitating rashes, sleep-depriving itch, and incessant irritability. Such presentations often lead to significant morbidity and inability to participate in activities of daily life, thus directly affecting patients’ quality of life.3,4 CD due to suspected personal hygiene products (PHP) and cosmetic products is an extremely common cause for patients to seek medical care, and thus, must be a condition that cosmetic dermatologists are knowledgeable in diagnosing and treating.
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Irritant Contact Dermatitis
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The most common type of CD, totaling approximately 80% of all CD cases,5 is ICD. ICD represents a nonspecific, non-immunologic ...