Co-induced Allergic Response to an Unrelated Allergen Exacerbates Imiquimod-Induced Psoriasis in Mice.

Psoriasis is classically regarded as a T-helper 1 (Th1) response-dominant disease believed to be antagonized by the Th2 response, which is responsible for allergic diseases, such as atopic dermatitis. The roles of these responses in psoriasis and the relationship between psoriasis and atopic dermatitis have received increasing attention because it is estimated that more than one million patients are concomitantly affected by psoriasis and atopic dermatitis. To address this, we attempted to determine the characteristics of imiquimod-induced psoriasiform lesions in mice with a concomitant allergic response after co-application of the unrelated allergen ovalbumin onto the skin.