People with AD are prone to skin infections, especially staph and herpes. In general, infections are hard to prevent but should be treated promptly to avoid aggravating the AD. It is important that persons with AD, or their parents, learn to recognize the early signs of skin infections and consult a physician immediately. Signs to watch for include redness, pus-filled bumps (pustules), and cold sores or fever blisters. Sometimes viral “colds” or “flu” cause AD flare-ups. Worsening can be avoided by taking extra skin care steps while the virus runs its course.