Cellulitis, skin infection Cellulitis is a bacterial skin infection that affects the deeper layers of the skin and soft tissue. It often causes an area of skin to become red, warm, swollen, painful, and tender. Cellulitis can start after bacteria enter through a cut, scrape, insect bite, cracked skin, athlete’s foot, eczema flare, wound, or other break in the skin. It can happen anywhere on the body, but it is common on the legs, feet, arms, and hands. What does cellulitis lo