What is it?
Cellulitis is a bacterial infection of the skin and, sometimes, of the tissues beneath the skin. The infection usually affects outer layers of the skin first, then spreads deeper into body tissues. Cellulitis can affect any area of the body covered by skin, but it is most common on the face or lower part of the legs. Cellulitis typically begins in an area of broken skin, like a cut, scratch, blister, splinter, or bite (animal, insect, or human). The infection can occur as a complication of chicken pox (also called varicella), when bacteria invade the skin of broken chicken pox blisters. Cellulitis may also start in areas of unbroken skin, especially in persons who have diabetes or who are taking medicines that affect the immune system.
Many different types of bacteria can cause cellulitis, but the two most common types are Staphylococcus aureus and Group A Streptococcus. Other types of bacteria that can cause cellulitis include Haemophilus influenzae (in persons who have not been immunized with the Hib vaccine) and Pasteurella multocida (from a cat or dog bite).
The incubation period of cellulitis depends on the type of bacteria causing the infection. This period may be as little as four hours to 24 hours, or it may take several days for symptoms to appear in an area of broken skin.
What are the symptoms?
Cellulitis begins as a small area of tenderness, swelling, warmth, and redness on the skin. As the redness spreads, the child may begin to feel "sick" and develop a fever, sometimes with chills and sweats. Enlarged lymph nodes ("swollen glands") are sometimes also found near the area of infected skin, and a red streak may appear on an arm or leg. Some especially worrisome cellulitis infections spread rapidly or may involve particularly delicate areas, such as the area around the eyes.
A doctor can usually make the diagnosis of cellulitis by asking a few questions and examining the area of affected skin. Sometimes, especially in younger children, the doctor may also order blood cultures (samples of blood that are examined in the laboratory for growth of bacteria). Positive blood cultures indicate that bacteria from a skin infection have spread into the bloodstream, causing bacteremia.
Children with mild cellulitis may be treated with oral antibiotics. It is important that the antibiotics be given for the full course of time prescribed by the doctor. A follow-up office visit after one or two days of taking antibiotics may be scheduled to check that the area of cellulitis has improved.
Depending on the area of the body affected by the cellulitis, elevating the affected body part may help ease discomfort and speed healing. Heat or warm soaks applied to the affected area may be suggested. For fever and discomfort, bed rest and proper doses of an over-the-counter children's antifever medication are advisable.
A child who has severe cellulitis is likely to be treated with intravenous antibiotics in the hospital. A child with cellulitis on the face may also require hospital treatment because the cellulitis may spread to tissues around the eye (known as orbital cellulitis) or the membranes covering the brain (which can cause meningitis).
How long does it last?
With antibiotic treatment, most cases of cellulitis resulting from a skin injury are cured in seven days to 10 days.
How can cellulitis be prevented?
Protecting a child's skin from cuts, scratches, blisters, and splinters can help prevent cellulitis. This may not be easy, especially with an active child who loves to explore or play sports. Some simple suggestions for skin protection that may help include elbow and knee pads while skating, a bike helmet during bike riding, shin guards while playing soccer, long pants and long-sleeved shirts while hiking in the woods, and sandals (not bare feet) on the beach. To help prevent animal bites, remind children to avoid touching unfamiliar pets; also, keep pets restrained when other children are visiting.
When a child does get a cut or scrape, wounds should be washed thoroughly with soap and water. An antibiotic ointment can be applied to the wound, which should be covered with a bandage or gauze.
For larger cuts, deep punctures, or bites (animal or human), it is advisable to seek a doctor's help as soon as possible to prevent cellulitis. Preventive antibiotics for some types of wounds, such as deep puncture wounds of the hands, may be given.
To help prevent cellulitis caused by Haemophilus influenzae bacteria, children should be immunized with the Hib vaccine. To help prevent cellulitis as a complication of chicken pox, children should be immunized with the varicella vaccine.
When should the doctor be called?
The doctor should be called whenever an area of your child's skin becomes red, warm, and painful - whether or not there are fever and chills. This is especially important if the affected area is on the child's face or hand.
Since cellulitis can happen very quickly after an animal bite, the doctor should be contacted whenever a child is bitten by an animal, especially if the puncture wound is deep. Human bites can also cause dangerous skin infections and should be seen by a doctor.