Cetirizine (Zyrtec) is a second-generation, over-the-counter antihistamine commonly used to relieve itching (pruritus) associated with eczema (atopic dermatitis). It works by blocking histamine, a chemical involved in allergic reactions that can worsen eczema symptoms. While it doesn’t treat the underlying skin inflammation, cetirizine can help reduce scratching, especially in patients with coexisting environmental allergies or nighttime itching. Unlike older antihistamines, it causes less drowsiness, though some people may still feel mildly sleepy. It’s often used alongside moisturizers and topical treatments like steroids or calcineurin inhibitors. Cetirizine is especially helpful for breaking the itch-scratch cycle and improving quality of life during eczema flares.