Rationale:

• Stratification of patients according to the severity of their infection and their comorbidities assists the clincian in deciding whether or not to hospitalize a patient with an infection.
• Mild, uncomplicated cellulitis can be treated out of the hospital with oral antibiotics. Although cellulitis may require surgical drainage, this can also be done as an outpatient.
• Moderate to severe cellulitis may require hospitalization for observation, surgery, control of comorbidities, and/or parenteral antibiotics.
• Parenteral antibiotics can be provided at home or in an infusion clinic if the patient is compliant with therapy and the cellulitis not too severe. These patients can recover at home with no increase in morbidity.
• Soft tissue infection associated with a “toxic appearance” may be an indication of necrotizing fasciitis or a more superficial streptococcal cellulitis. Observation status for these patients in a clinical decision unit is an appropriate management strategy until the clinical course becomes clear or laboratory values indicate whether or not the patient is developing sepsis syndrome with multiorgan dysfunction.

Evidence:

• Classification schemes for cellulitis and soft tissue infection have been reported to assist in treatment decisions (33; 58).
• Necrotizing fasciitis and myonecrosis are associated with shock and organ failure, and have mortality rates ranging from 30% to 70% as well as extensive morbidity (21). These patients require hospitalization for surgical debridement, prompt antibiotic treatment, and treatment and monitoring in the ICU (35).
• Patients with soft tissue infection associated with severe pain, crepitus, ecchymotic or bullous lesions that are violaceous or blue, may have severe infection or necrotizing fasciitis and require hospitalization (21; 34; 35; 59).
• A marked left shift, elevated CPK, thrombocytopenia, elevated serum creatinine, and hypocalcemia may indicate severe infection as well as toxic shock syndrome. Such patients require hospitalization (21).
• Rapid expansion of soft tissue infection and evidence of multiorgan dysfunction are associated with deeper infection, such as necrotizing fasciitis or gas gangrene. Such patients require hospitalization (21).
• Some strains of group A streptococcus and S. aureus produce potent toxins that can induce toxic shock syndrome without necrotizing fasciitis. These patients are at great risk for shock and organ failure and require hospitalization for critical care monitoring and treatment (39; 59).
• Many patients have seen physicians two or three times before they finally present with obvious signs of necrotizing fasciitis or toxic shock syndrome (34; 59). These patients would benefit from being observed for a period of time in a clinical decision unit under “observation status.” A study of patients with skin and soft tissue infections admitted to an observation unit reported that 38% required subsequent admission. Risk factors for subsequent admission were female gender and a leukocyte count >15,000/µL (60).
• Early discharge from the hospital of patients with cellulitis, when compared to conventional discharge, results in similar outcomes, except that the former may be associated with more rapid convalescence (61; 62; 63).

Comments:

• From 2000 to 2004, hospital admissions for skin and soft tissue infections in the U.S. increased by 29%, as opposed to community-acquired pneumonia, which showed no such increase. There was a particular increase in community-associated MRSA infections and in infections in patients under age 65. Although the authors could not determine that the increase in hospital infections was due to a growing prevalence of community-associated MRSA, they proposed a linkage to an increasing incidence of antimicrobial drug failure in outpatients (64). This problem should be addressed by an increased awareness of and a more aggressive approach to managing all MRSA infections.
• Hospitalization is useful for patients who are critically ill with severe infection. Clinical decision units allow clinicians to observe patients over a period of time under “observation status” to determine their severity of illness and whether they really require hospitalization or whether they can be managed as outpatients.