Treatment Guideline Chart
Cellulitis is an acute spreading skin infection that may go deep, involving the subcutaneous tissues.
It typically occurs in areas where the skin integrity has been compromised.
May result from blood-borne spread of infection to the skin and subcutaneous tissues.
It is commonly caused by beta-hemolytic streptococci and Staphylococcus aureus in adults and Haemophilus influenzae type B in patients <3 year of age.

Cellulitis_erysipelas%20(pediatric) Treatment

Principles of Therapy

Choice of Route of Administration for Empiric Treatment

Oral Antibiotics

  • If lymphadenopathy, fever & other constitutional signs are not present [eg white blood cells (WBC) <15,000], then may typically treat patient w/ oral antibiotics on an outpatient basis

Parenteral Antibiotics

  • If symptoms do not improve or if disease progresses significantly w/in the first 24-48 hours parenteral therapy may be needed
  • If lymphadenopathy, fever or constitutional signs are present
  • Neonates should be admitted & given initial parenteral therapy if w/ moderate to severe presentation
  • Considered in patients w/ comorbidities [eg diabetes mellitus (DM), peripheral vascular diseases]

Choice of Antibiotic

  • Tailored according to known pathogen, comorbid condition, & special situations like water (eg salt or freshwater) exposure or animal bites
    • Treatment should also address underlying predisposing conditions
  • Empiric therapy may be started pending culture results
    • For patients w/ purulent cellulitis, treatment is directed towards Methicillin-resistant S aureus (MRSA) since it is the dominant pathogen in this type of cellulitis; therapy for beta-hemolytic streptococci is likely not needed
    • For patients w/ nonpurulent cellulitis, treatment is directed towards Methicillin-sensitive S aureus (MSSA) & beta-hemolytic streptococci
      • Empiric therapy for MRSA may be needed if patient has signs of systemic infection, is unresponsive to initial therapy, has recurrent infection, or has a previous episode of or is at high risk for MRSA infection

Penicillins (Beta-lactamase resistant)

  • Recommended therapy for patients w/ erysipelas, moderate nonpurulent & purulent cellulitis, & MRSA infection
  • Recommended antibiotics against mild nonpurulent cellulitis caused by group A Streptococcus or S aureus
    • Some authorities recommend antistaphylococcal penicillin alone while others advocate antistaphylococcal penicillin + Penicillin or Amoxicillin
    • Combination may increase adverse effects 
  • Recommended for initial treatment of neonates w/ moderate to severe cellulitis
  • Also recommended for recurrent cellulitis


Penicillin G [Intravenous (IV)]

  • Used for erysipelas & moderate nonpurulent uncomplicated cellulitis
  • Treatment option for patients w/ recurrent cellulitis
  • Observe patient for localized S aureus infection

Cephalosporins (1st Generation)

  • If staphylococcal infection is suspected
  • Usually sufficient for mild nonpurulent uncomplicated cellulitis

Cephalosporins (2nd & 3rd Generation) [Parenteral]

  • Usually used empirically in diabetes mellitus (DM) patients who have early mild cellulitis
  • Treatment alternative for patients w/ moderate nonpurulent cellulitis

Aminopenicillin/Beta-Lactamase Inhibitors

  • Considered 2nd-line alternative by some authorities
  • Effective & especially useful in the presence of bone or joint infection


  • Eg Erythromycin, Roxithromycin
  • May be used if patient is allergic to Penicillin
  • Macrolide resistance among Group A Streptococci has increased & has become a concern in some countries
  • Erythromycin is the main macrolide used unless Erythromycin resistance is widespread in the community
  • Also used for prophylactic treatment against recurrent cellulitis
  • Studies showed that the efficacy of Roxithromycin for erysipelas was comparable to that of Benzylpenicillin

Other Antibiotics

  • Clindamycin
    • Used in patients allergic to Penicillin & cephalosporins
    • Alternative therapy for patients w/ nonpurulent or purulent cellulitis caused by Methicillin-sensitive S aureus (MSSA) or Methicillin-resistant S aureus (MRSA) infection
  • Co-trimoxazole
    • Used for nonpurulent cellulitis & moderate purulent cellulitis
    • Has very good activity against community-acquired MRSA but not to streptococci
  • Linezolid
    • Used in patients allergic to Penicillin & for complicated cellulitis & erysipelas
  • Vancomycin
    • Treatment option for patients allergic to Penicillin
    • Combination w/ Piperacillin/Tazobactam or Imipenem/Meropenem is recommended for patients w/ severe nonpurulent cellulitis
    • Combination w/ Cefotaxime or Gentamicin is recommended as 1st-line parenteral treatment for neonates w/ MRSA infections
    • Also used for patients w/ penetrating trauma, nasal colonization w/ MRSA, & IV drug use


  • Eg Ciprofloxacin, Levofloxacin, Moxifloxacin, Ofloxacin
  • Those that have enhanced activity against Gram-positive bacteria have been shown to be effective
  • Used for cellulitis caused by Vibrio vulnificus
  • Not recommended for patients living in MRSA-prevalent regions


  • Eg Doxycycline, Minocycline
  • May be considered for moderate-severe purulent cellulitis, MSSA, & MRSA infections

Length of Therapy

  • It is typically recommended that once erythema, warmth & edema have subsided significantly, patient  may be treated for an additional 10 days w/ oral antibiotics
  • Antibiotic therapy for neonates is usually administered for 7-10 days; 5-10 days for patients >1 month
  • Treatment duration may be extended for severe cases
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