What is a leading factor contributing to females' high sensitization to nickel?

The high sensitization to nickel among females can be largely attributed to the increased prevalence of ear piercing. This practice, which is more common in females than males, often involves the insertion of earrings that can contain nickel. When nickel-containing materials come into contact with the skin, particularly in areas such as the ears where the skin may be more sensitive due to pierced holes, the likelihood of developing an allergic reaction increases.

Moreover, many decorative earrings are made from or coated with nickel, leading to prolonged exposure, which can heighten sensitization. As a result, this increased exposure through ear piercings and the materials chosen for jewelry contribute significantly to higher rates of nickel allergies in females.

While increased skin exposure, frequent use of jewelry, and use of cosmetics may also play roles in sensitization, they are not as specifically linked to the behavior of ear piercing and the associated use of earrings as a primary factor. This makes the connection between ear piercings and nickel sensitization particularly strong among the female population.