Redness of the cheeks that worsens when you go outside can occur for several reasons, including skin sensitivity, sun exposure, irritation from previous treatments, or conditions such as rosacea. Benzoyl peroxide and Tyrorein cream (arbutin, kojic acid and tranexamic acid) may sometimes make the skin more sensitive, especially to sunlight, and this effect may persist for some time after stopping treatment. To help calm the redness, use a gentle cleanser, a fragrance-free moisturiser and a broad-spectrum sunscreen with SPF 30 or higher every day. Avoid harsh scrubs, very hot water, and products containing alcohol or strong acids until your skin settles. If the redness is persistent, associated with burning, visible blood vessels, or acne-like bumps, it is advisable to consult a dermatologist. They can determine whether you have any underlying skin conditions and recommend the most appropriate treatment.