a-z health information

Cellulitis is a common skin infection caused by bacteria.

See also:

• Orbital cellulitis
• Periorbital cellulitis

Skin infection - bacterial

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, 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:

• Fever
• 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 the area of redness

Signs of infection:

• Chills or shaking
• Fatigue
• General ill feeling
• Muscle aches and pains
• Warm skin
• Sweating

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

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 done:

• Blood culture
• Complete blood count (CBC)
• Culture of any fluid or material inside the affected area

Most of the time, treatment involves antibiotics taken by mouth and close follow-up by your doctor. You may be given painkillers.

You should 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 with 7 - 10 days of antibiotics. 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. The cracks in the skin from the fungal infection allows the bacteria entry to the skin.

• Blood infection (sepsis)
• Bone infection (osteomyelitis)
• Inflammation of the lymph vessels (lymphangitis)
• Inflammation of the heart (endocarditis)
• Meningitis
• Shock
• Tissue death (gangrene)

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 immediately 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, ed. Clinical Dermatology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2009; chap 9.

Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 90.