What should you know about cellulitis turning black?

Cellulitis commonly causes red, warm, swollen, tender skin. A patch that becomes black, grey, purple, dusky, blistered, or numb is different from ordinary redness and may reflect damaged tissue, reduced blood flow, or infection extending deeper. Colour can be harder to judge on darker skin, so compare with the surrounding area and describe any change clearly. Do not assume the change is bruising or wait for it to settle.

Go to an emergency department or contact emergency medical services now if cellulitis is turning black, particularly when the change is spreading or accompanied by severe pain, numbness, blisters, fever, weakness, or a foul-smelling wound. Do not cut, drain, scrub, massage, or apply creams to the area. Keep it protected, avoid eating or drinking if urgent surgery might be considered, and take a list of medicines and health conditions. Diabetes can increase the risk from foot and skin infections.

Urgent assessment is needed even without fever. Confusion, faintness, fast breathing, extreme weakness, or cold clammy skin may accompany sepsis. Call for help rather than driving yourself if you feel faint or confused. A clinician may need to assess circulation, tissue depth, and the source of infection without relying on skin colour alone.

Ask what is causing the colour change, whether deeper tissue or circulation is involved, and what tests or treatment are needed. Ask how to protect the area, which symptoms mean you should return immediately, and how conditions such as diabetes affect follow-up.