The emollient, derived from sheep’s wool, took the stage at the American Contact Dermatitis Society’s annual meeting because of debate over its allergenicity.
Is it fragrance or latex? Jewelry metals or skin cream preservatives? A person often ponders these questions when experiencing a mysterious allergy-induced rash on their skin.
Known as contact dermatitis, these itchy, red, and sometimes unbearable rashes can be caused by a wide range of substances and products.
Although not common, some people can have a skin reaction to products that contain lanolin. This highly emollient compound is produced by the sebaceous glands in sheep's skin and secreted into their wool.
Still, since the 1920s, scientists and physicians have debated whether lanolin is truly allergenic. In addition, patch testing for lanolin allergy can be paradoxical, leaving many questions about the sheep-derived moisturizer unanswered.
Because of the ongoing debate, lanolin was dubbed the American Contact Dermatitis Society’s "Contact Allergen of the Year” for 2023 at the organization’s 34th annual meeting on March 16 in New Orleans.
According to a news report, the "Contact Allergen of the Year" can include allergens with increasing frequency, newly reported allergens, and known allergens with a new twist in perspective.
In a paper highlighting the newly crowned allergen, Blair A. Jenkins, M.D., Ph.D., and Donald V. Belsito, M.D., wrote, "controversy as to lanolin's allergenicity began in the 1920s and remains an issue."
Although the authors say that contact allergy to lanolin is estimated to occur in 0.4% of the European population, "the most appropriate patch test preparation(s) for detecting allergy remain disputed."
"Detection of lanolin-induced contact dermatitis in diseased skin by patch testing on normal skin may lead to false negative results. [While] patients with a positive patch test to lanolin may tolerate use of lanolin on normal skin," the authors say.
Moreover, the authors note that people with stasis dermatitis, leg ulcers, perianal/genital dermatitis, and atopic dermatitis (AD) may be more at risk for lanolin allergy. Children and older adults are also at greater risk of developing contact allergy to lanolin, but this is likely due to a higher prevalence of AD in children and stasis dermatitis/leg ulcers in older people.
In addition, the authors indicate that non-Hispanic white people are more likely to have a lanolin allergy than non-Hispanic Black individuals.
In the news report, Belsito says, "medical grade and highly purified anhydrous lanolin, which contain less than 2.5% and less than 1.5% of free alcohols, respectively, can still elicit or induce a contact allergy."
Belsito also notes that modern wool clothing and textiles do not contain lanolin, so most people allergic to lanolin can still wear wool.
Still, despite known challenges with lanolin allergy patch testing, people who suspect they may be reacting to lanolin-containing products should consider visiting a dermatologist or allergist for diagnosis and appropriate treatment.