Which common ingredient in tanning lotions is known to cause allergic reactions?

Dihydroxyacetone (DHA) is the correct answer because it is the primary active ingredient used in many self-tanning products and lotions to create a bronzed appearance on the skin. While DHA is generally considered safe for topical use, some individuals may develop allergic reactions or skin sensitivities to it. This can manifest as irritation, rashes, or other allergic responses, leading to discomfort for those affected.

In contrast, other ingredients listed, such as alpha hydroxy acid, vitamin E, and mineral oil generally have less likelihood of causing allergic reactions. Alpha hydroxy acids are commonly used for exfoliation, vitamin E is known for its moisturizing properties, and mineral oil is often used as an emollient. While sensitivities can occur with all substances, DHA is uniquely linked to tanning lotions and has a higher association with allergic reactions in certain individuals. This makes it a key ingredient to be aware of when considering potential allergic responses in clients using tanning products.