Chapter 10 Cellulitis
PATHOPHYSIOLOGY
Cellulitis is an infection that affects the skin and subcutaneous tissue. The site of involvement is most commonly an extremity, but cellulitis may also occur on the scalp, the head, and the neck. Organisms causing cellulitis include Staphylococcus aureus, group A streptococci, and Streptococcus pneumoniae. Once common, invasive infection caused by Haemophilus influenzae type B is now rare as a result of childhood immunization. A history of trauma or, in young children, an upper respiratory tract infection or sinusitis, is often reported. The site of infection is characterized by a swelling with indistinct margins that is tender and warm. Infection may extend to deeper tissues or spread systemically. See Box 10-1 for orbital and periorbital cellulitis symptoms. Outcome is excellent with treatment.
CLINICAL MANIFESTATIONS
LABORATORY AND DIAGNOSTIC TESTS
1. Complete blood count—used to assess elevation of white blood cell count, which indicates underlying pathology. Refer to Appendix D for normal values and ranges of this test.
2. Blood cultures—used to identify organism and to determine appropriate antibiotic therapy. Blood cultures are positive in fewer than 5% of patients with cellulitis and are obtained in more severe cases.
3. Culture of needle aspirate from tissue—used to identify organism and to determine appropriate antibiotic therapy. Needle aspirate culture is positive in 5% to 40% of patients with cellulitis.
4. Radiographic study of paranasal sinuses—used in periorbital cellulitis to assess severity of condition by identifying opacification of sinuses.
5. Computed tomographic scan of orbit and paranasal sinuses—used to rule out orbital involvement.
MEDICAL MANAGEMENT
Children with cellulitis may be treated with oral antibiotics as outpatients if they have localized symptoms without fever. When systemic symptoms are present, the child is admitted to the hospital for a course of intravenous (IV) antibiotics. Warm compresses are applied to the site. The site is elevated and immobilized whenever possible. Acetaminophen is given as needed to manage fever and pain. For the first 24 to 36 hours after effective antibiotic therapy is begun, it is not unusual for the cellulitis to appear to progress. Antibiotic administration may be changed from IV to oral administration when symptoms of redness, warmth, and swelling have significantly improved. A total 10- to 14-day course of antibiotics is given. Incision and drainage may be performed if the area becomes suppurative.
NURSING INTERVENTIONS
Discharge Planning and Home Care
Stevens DL, et al. Practice guidelines for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis. 2005;41(15 November):1373.
Vu BLL, et al. Development of a clinical severity score for preseptal cellulitis in children. Pediatr Emerg Care. 2003;19(5):302.
Wald ER. Periorbital and orbital infections. Pediatr Rev. 2004;25(9):312.
