Cellulitis

Cellulitis is an acute infection of the skin and underlying connective tissue characterized by erythema, swelling, warmth, and pain. It is a common pediatric complication of trauma, insect bites, and ulcer; however, it may be seen without any trauma to the skin.' Cellulitis may be the presenting sign of disease states such as septic arthritis, osteomyelitis, pyomyositis, or sinusitis.2 The various locations of cellulitis in children are frequently linked to specific causative bacterial organisms, and this association facilitates the diagnosis and allows for the administration of the proper antimicrobial agent before confirmation by culture is complete.3 The following review of cellulitis in infants and children considers skin infections by specific, common sites.

Buccal Cellulitis

Buccal cellulitis occurs most commonly in infants from 6 months to 2 years of age.4 There is usually no history of trauma. The causative agent prior to routine immunization was Haemophilus influenzae type B (HIB). Rarely, Staphylococcus aureus and Streptococcus pneumoniae may be the pathogens involved. In this age group, positive blood cultures usually reveal H. influenzae type B. These bacteria are associated with fevers higher than 39C, and white blood cell counts greater than 15,000.35 Haemophilus influenzae type B has been isolated from middle ear cultures in twothirds of infants with buccal cellulitis,6 whereas in isolated otitis media, nontypable H. influenzae is usually isolated from middle ear cultures. Routine immunization with HIB has successfully reduced all forms of H. influenzae type B infections in children.

In neonates under 3 months of age, the only presenting sign of group B streptococcus bacteremia, which carries a mortality of 50%, may be facial cellulitis.7 Treatment for this suspected pathogen is ampicillin. In any age group, the cheek is swollen, tender, and mildly erythematous with occasional progression to a violaceous hue. These are the classic signs of H. influenzae bacteremia4,7 (Figure 1). Cultures of blood, cerebrospinal fluid, and lesion aspirates should be obtained for all patients.36 Rare causes include nontuberculous Mycobacterium, such as M. chelonei, which has an indolent course after a wound infection following a recent injury. Treatment requires incision and drainage, as the organisms are typically resistant to antituberculous medications.8 The differential diagnosis5 is outlined in Table I.

Periorbital Cellulitis

Periorbital and orbital cellulitis, both common infections in children, need to...