How is cellulitis different in people with diabetes?

Cellulitis is a bacterial infection in deeper layers of skin. Diabetes can reduce feeling in the feet or legs, so a cut, blister, pressure spot, or burn may go unnoticed. Changes in blood flow and glucose control can also make tissue repair more difficult. Redness, warmth, swelling, tenderness, and fever remain useful clues, but pain may be limited and the border can be difficult to judge on deeper skin tones. A foot wound, ulcer, or fungal infection between the toes may provide an entry point. Cellulitis should be distinguished from a pressure injury, allergy, gout, or a diabetic foot problem.

Contact a clinician promptly for new warmth, swelling, redness, or a sore on the foot or leg. Do not squeeze, lance, or soak the area. Wash gently, cover an open wound with a clean dressing, and reduce pressure on the affected foot until advice is given. Check glucose as directed and take prescribed antibiotics exactly as instructed; do not use leftover tablets. Keep a pen outline of the visible edge only if a clinician recommends it, because changes may help show whether inflammation is spreading. Daily foot checks, suitable footwear, and treatment of cracked skin can reduce future entry points.

Seek urgent care for rapidly spreading swelling or redness, severe pain, black or grey skin, blisters, pus, red streaks, fever, chills, vomiting, confusion, faintness, or marked weakness. Go quickly if the infection involves the face or eye, if a foot wound exposes deeper tissue, or if the person cannot bear weight. A diabetic foot infection can worsen beneath the skin even when the surface looks modest, so new loss of feeling or a sudden change in colour also warrants same-day assessment.

Ask whether the infection is limited to the skin or involves a foot ulcer, joint, or deeper tissue. Confirm how to take treatment, when improvement should be checked, how to protect the wound, and whether glucose medicines need monitoring during illness. Ask for a clear plan for dressings, footwear, and follow-up.