Internal Medicine

0521779407-C01 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:53

Cellulitis 293

tests

■Blood cultures low yield and rarely alter therapy or outcome; indi-

cated in drug users, immunocompromised and those with clinical

sepsis

■Aspiration of leading edge (using non-bacteriostatic saline) useful in

immunocompromised, those suspected of having an unusual organ-

ism, those failing to respond to therapy

■Culture bite wound aerobically and anaerobically, if infected

■X-rays (plain films/MRI) if suspect osteomyelitis or foreign body; in

diabetes and peripheral vascular disease, probing ulcer to bone has

89% positive predictive value for osteomyelitis

differential diagnosis

■Uncomplicated cellulitis versus cellulitis associated with osteo-

myelitis or deep tissue infection (necrotizing fasciitis, myositis)

■Tissue necrosis, cloudy drainage, crepitance, anesthesia of involved

skin (from dermal nerve infarction) suggest deep tissue infection

■Osteomyelitis excluded by probing wound and x-rays

management

■Assess severity of illness and hospitalize, if indicated

■Elevate involved area and treat predisposing condition (edema, tinea

pedis)

■Diabetic and vascular ulcers with localized cellulitis may need minor

debridement; if systemic symptoms present, surgical consultation

for more aggressive debridement

■Human bites usually hospitalized

■All bites should be irrigated and debrided of devitalized tissue

■Tetanus and rabies immunization, if indicated, in animal bites

specific therapy

■Community-acquired – dicloxacillin, cephalexin or clindamycin

(severe penicillin allergy); if hospitalized – nafcillin, cefazolin or van-

comycin (severe penicillin allergy)

If suspect community-acquired MRSA (see epi above) – TMP-SMX,

doxycycline, clindamycin

■Nosocomial – second- (cefuroxime) or third- (ceftriaxone) genera-

tion cephalosporin

■IV drug use – dicloxacillin, cephalexin (or Augmentin if Eikenella

suspected); in penicillin-allergic patient, clindamycin (plus doxycy-

cline if Eikenella suspected); hospitalized – third-generation cep-

halosporin