Cellulitis is a common skin infection caused by bacteria.
Skin infection - bacterial
Causes, incidence, and risk factors
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. Skin in the infected area will become red, hot, irritated, swollen, and painful.
Risk factors for cellulitis include:
- Cracks or peeling skin between the toes
- History of peripheral vascular disease
- Injury or trauma with a break in the skin (skin wounds)
- Insect bites and stings, animal bites, or human bites
- Ulcers from certain diseases, including diabetes and vascular disease
- Use of corticosteroid medications or medications that suppress the immune system
- Wound from a recent surgery
Symptoms of cellulitis include:
- Pain or tenderness in the affected area
- Skin redness or inflammation that gets bigger as the infection spreads
- Skin sore or rash that starts suddenly, and grows quickly in the first 24 hours
- Tight, glossy, stretched appearance of the skin
- Warm skin in the area of redness
Signs of infection:
- Chills or shaking
- General ill feeling
- Muscle aches and pains
- Warm skin
Other symptoms that can occur with this disease:
- Hair loss at the site of infection
- Joint stiffness caused by swelling of the tissue over the joint
- Nausea and vomiting
Signs and tests
The health care provider will perform a physical exam. This may reveal:
- Redness, warmth, and swelling of the skin
- Possible drainage, if there is an infection
- Swollen glands (lymph nodes) near the affected area
Your health care 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.
At home, raise the infected area higher than your heart to reduce swelling. Rest until your symptoms improve.
You may need to stay in a hospital if:
- You are very sick (for example, you have a very high temperature, blood pressure problems, or nausea and vomiting that does not go away)
- You have been on antibiotics and the infection is getting worse
- Your immune system is not working well (due to cancer, HIV)
- You have an infection around your eyes
- You require antibiotics through a vein (IV)
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 diseases or your immune system is not working properly.
People with fungal infections of the feet may have cellulitis that keeps coming back. Cracks in the skin from the fungal infection allows the bacteria to get into the skin.
- Blood infection (sepsis)
- Bone infection (osteomyelitis)
- Inflammation of the lymph vessels (lymphangitis)
- Inflammation of the heart (endocarditis)
- Tissue death (gangrene)
Calling your health care provider
Call your health care provider if:
- You have symptoms of cellulitis
- You are being treated for cellulitis and you develop new symptoms, such as persistent fever, drowsiness, lethargy, blistering over the cellulitis, or red streaks that spread
Seek medical attention right away if the cellulitis is on your face.
Protect your skin by:
- Keeping your skin moist with lotions or ointments to prevent cracking
- Wearing shoes that fit well and provide enough room for your feet
- Learning how to trim your nails to avoid harming the skin around them
- Wearing appropriate protective equipment when participating in work or sports
Whenever you have a break in the skin:
- Clean the break carefully with soap and water. Apply an antibiotic cream or ointment every day.
- Cover with a bandage and change it every day until a scab forms.
- Watch for redness, pain, drainage, or other signs of infection.
Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 5th ed. Philadelphia, Pa.: Elsevier Mosby; 2009; chap 9.
Kaplan AP. Urticaria and angioedema. In: Adkinson NF Jr., Bochner BS, Busse WW, et al., eds. In: Middleton’s Allergy Principles and Practice. 7th ed. Philadelphia, Pa.: Elsevier Mosby; 2008:chap 61.
Last reviewed 5/15/2013 by Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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