A woman with discoid lupus erythematosus is experiencing an exacerbation of her rash despite corticosteroid use. What is the most appropriate additional treatment?

The most appropriate additional treatment for a woman with discoid lupus erythematosus experiencing an exacerbation of her rash despite corticosteroid use is hydroxychloroquine. Hydroxychloroquine is an antimalarial medication that is commonly used to manage various conditions related to lupus, including discoid lupus erythematosus. It works by modulating the immune response and has anti-inflammatory properties, making it effective in reducing skin lesions and preventing further flares.

In the context of discoid lupus erythematosus, which is characterized by localized skin lesions, hydroxychloroquine can improve skin symptoms and help control disease activity when corticosteroids alone are not sufficient. This makes it a preferred option for managing exacerbations, as it can lead to symptom improvement and lower the need for higher doses of corticosteroids, which can have significant side effects.

Other medications listed, while they may have their own therapeutic effects in different conditions, are either not specifically indicated for lupus or do not address the immune-mediated nature of discoid lupus erythematosus in the same effective manner as hydroxychloroquine. For instance, isotretinoin is primarily used for severe acne and might not be beneficial for lupus lesions. Nicotinamide, a