From the Guidelines

Inpatient management of cellulitis typically involves empiric antibiotic therapy against Gram-positive bacteria, particularly streptococci.

The choice of antibiotic should be based on the severity of the infection, the presence of systemic signs of infection, and the patient's risk factors for methicillin-resistant Staphylococcus aureus (MRSA) 1.
For patients with non-severe cellulitis, oral beta-lactams, such as cephalexin or amoxicillin, may be sufficient 1.
For patients with more severe infections or those at risk for MRSA, intravenous vancomycin or other MRSA-active antibiotics, such as linezolid or daptomycin, may be necessary 1.
The duration of antibiotic therapy is typically 5-7 days, but may be extended if the infection has not improved within this time period 1.
Elevation of the affected area and treatment of predisposing factors, such as edema or underlying cutaneous disorders, are also recommended 1.

For streptococcal coverage: cephalexin, amoxicillin, or clindamycin 1.
For MRSA coverage: vancomycin, linezolid, or daptomycin 1.
For patients with severe infections or those at risk for MRSA, combination therapy with a beta-lactam and an MRSA-active antibiotic may be considered 1.

Patients with systemic signs of infection, such as fever or hypotension, may require more aggressive treatment, including intravenous antibiotics and supportive care 1.
Patients with underlying medical conditions, such as diabetes or immunosuppression, may require more careful monitoring and adjustment of antibiotic therapy 1.

From the Research

The decision to admit a patient with cellulitis to the hospital is based on several factors, including the severity of the infection, the presence of comorbidities, and the patient's overall health status 2.
Patients who are admitted to the hospital for cellulitis are often older, less mobile, and have more comorbidities than those who are treated as outpatients 2.
Inpatient management of cellulitis typically involves the use of intravenous antibiotics, and patients who are admitted to the hospital are more likely to experience complications such as acute renal failure and nosocomial infection 2.
The mortality rate for patients hospitalized with cellulitis is relatively low, ranging from 0.5% to 1.1% depending on the population being studied 3.
Current recommendations for the management of cellulitis include the use of empiric antimicrobial therapy based on patient risk factors and regional susceptibility patterns, as well as consideration of alternative diagnoses such as venous stasis dermatitis, contact dermatitis, and deep vein thrombosis 4, 5, 6.

The presence of comorbid illnesses does not necessarily exclude patients from being treated as outpatients, but careful selection is essential to ensure safe outcomes 2.
Patients with certain underlying conditions, such as diabetes or immunocompromised states, may require more aggressive treatment and closer monitoring 4, 6.
The use of Hospital in the Home (HITH) programs or other outpatient treatment options may be suitable for some patients with cellulitis, particularly those who are younger and have fewer comorbidities 2.

Cellulitis can be difficult to diagnose, and a broad differential diagnosis should be considered, including other dermatologic conditions such as venous stasis dermatitis, contact dermatitis, and deep vein thrombosis 4, 5, 6.
Laboratory tests and skin biopsy may be helpful in confirming the diagnosis of cellulitis, particularly in cases where the diagnosis is uncertain 6.