What should you know about ascending cellulitis?

It is not a problem to watch at home when the affected area is enlarging. Antibiotic treatment may be needed, and delay can allow infection to involve deeper tissues, lymphatic vessels or the bloodstream.

Cellulitis begins when bacteria enter through a break in the skin, which may be tiny or difficult to see. Cracks between the toes from athlete's foot, wounds, ulcers, insect bites or scratching can provide an entry point. The skin often becomes hot, tender, swollen and red; streaking toward the body can suggest lymphatic spread.

Cellulitis commonly presents with painful skin and swelling, while some affected people develop fever or feel unwell. Diabetes, poor circulation, lymphoedema and reduced immune function can complicate assessment and treatment, but infection can also occur without those factors.

Seek same-day medical assessment for suspected spreading cellulitis. A clinician may examine the skin, look for an entry wound or abscess, check circulation and decide whether oral or intravenous antibiotics are appropriate. Take prescribed antibiotics exactly as directed and do not use leftover medicine from another illness.

Rest and elevate an affected arm or leg if comfortable. Keep any wound clean and covered, drink fluids if you can, and avoid massage, squeezing, cutting or applying unprescribed steroid cream to the inflamed area. Note whether redness advances beyond its previous edge, but do not let monitoring delay care.

Go to an emergency department for rapidly spreading redness, severe or disproportionate pain, blistering, dark or numb skin, confusion, faintness, breathing difficulty, marked drowsiness, repeated vomiting or inability to drink. Fever with worsening skin changes also needs urgent reassessment. These signs may indicate severe infection, tissue injury or sepsis.

After treatment starts, obtain prompt review if the affected area keeps expanding, new streaks appear, symptoms worsen or you cannot take the prescribed antibiotic. People with diabetes, immune suppression or poor limb circulation should have a lower threshold for urgent evaluation.

Ask where the bacteria may have entered, whether an abscess or wound needs separate care, how to recognise improvement and when you should return for reassessment. If infections recur, ask about treating athlete's foot, skin cracks, swelling or another condition that weakens the skin barrier.