How long do antibiotics take to work for cellulitis?

Cellulitis affects deeper layers of skin, so visible colour and swelling may lag behind how you feel. The edge of redness should stop advancing, tenderness should gradually settle, and fever or chills should improve. Marking the edge with a pen can help you notice whether it is spreading, provided the skin is intact and a clinician has not advised otherwise.

If the redness continues to expand or symptoms have not started to improve after two or three days, the diagnosis or treatment may need review. Take the prescribed antibiotic for the full instructed course unless your clinician changes the plan.

Take doses on schedule, rest the affected limb when possible, and raise it to help with swelling. Drink normally unless you have been given fluid restrictions. Keep any crack, blister, or wound clean and covered, and avoid shaving, scratching, or applying irritating products over the area.

Record fever, pain, the size of redness, and any new symptoms. Do not use leftover antibiotics or share medicine with another person.

Seek urgent care if redness spreads quickly, pain is severe or out of proportion, the skin becomes numb or dusky, or blisters develop. Emergency assessment is needed for confusion, faintness, breathing difficulty, severe weakness, or fever with shaking chills. Arrange earlier review if cellulitis affects the face or eye area, or if you have diabetes or reduced immunity.

Ask when your skin should be checked again, whether you should mark the border of redness, and what to do if a dose causes a reaction. Clarify which symptoms mean you need hospital assessment rather than a routine follow-up.