Which additional factor increases the risk of eczema in a 14-year-old patient with a family history and allergic rhinitis?

The increased risk of eczema in a 14-year-old patient with a family history of atopy and allergic rhinitis can be attributed to the close relationship between eczema, asthma, and allergic rhinitis, which are all components of the atopic triad. A family history of atopic conditions suggests a genetic predisposition to such diseases. Asthma, being a chronic inflammatory disease involving the airways, often coexists with eczema and allergic rhinitis due to shared underlying mechanisms, such as immune dysregulation and hypersensitivity.

In this scenario, the presence of asthma as an additional factor further emphasizes the patient's atopic status, suggesting a higher likelihood of developing or exacerbating eczema. Children and adolescents with one atopic condition, like allergic rhinitis, are at an increased risk of developing others, such as asthma and eczema, due to their immune system's tendency to overreact to environmental allergens.

While the other conditions listed may have their own associations with allergies or other health issues, they do not have the same strong, well-established link to the development and exacerbation of eczema in the context provided.