Cellulitis is a common skin infection caused by bacteria. It affects the middle layer of the skin (dermis) and the tissues below. Sometimes, muscle can be affected.
Skin infection - bacterial; Group A streptococcus - cellulitis; Staphylococcus - cellulitis
Staphylococcus and streptococcus bacteria are the most common causes of cellulitis.
Normal skin has many types of bacteria living on it. When there is a break in the skin, these bacteria can cause a skin infection.
Risk factors for cellulitis include:
Symptoms of cellulitis include:
Exams and Tests
The health care provider will perform a physical exam. This may reveal:
The provider may mark the edges of the redness with a pen, to see if the redness goes past the marked border over the next several days.
Tests that may be ordered include:
You will likely be prescribed antibiotics to be taken by mouth. You may be given pain medicine as well, if needed.
At home, raise the infected area higher than your heart to reduce swelling and speed up healing. Rest until your symptoms improve.
You may need to stay in a hospital if:
Cellulitis usually goes away after taking antibiotics for 7 to 10 days. Longer treatment may be needed if cellulitis is more severe. This may occur if you have a chronic disease or your immune system is not working properly.
People with fungal infections of the feet may have cellulitis that keeps coming back, especially if you have diabetes. Cracks in the skin from the fungal infection allow the bacteria to get into the skin.
The following may result if cellulitis isn't treated or treatment doesn't work:
When to Contact a Medical Professional
Call your provider right away if:
Protect your skin by:
Whenever you have a break in the skin:
Habif TP. Bacterial infections. In: Habif TP, ed. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 6th ed. Philadelphia, PA: Elsevier; 2016:chap 9.
Heagerty AHM, Harper N. Cellulitis and erysipelas. In: Lebwohl MG, Heymann WR, Berth-Jones J, Coulson I, eds. Treatment of Skin Disease: Comprehensive Therapeutic Strategies. 5th ed. Philadelphia, PA: Elsevier Saunders; 2018:chap 40.
Pasternak MS, Swartz MN. Cellulitis, necrotizing fasciitis, and subcutaneous tissue infections. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 95.
Review Date: 4/16/2019
Reviewed By: Michael Lehrer, MD, Clinical Associate Professor, Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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