What antibiotic should be prescribed for cellulitis of the left hand?

From the Guidelines

For cellulitis of the left hand, I recommend starting with oral cephalexin 500 mg four times daily for 5-7 days, as this first-generation cephalosporin effectively targets the most common causative organisms, Staphylococcus aureus and Streptococcus species 1.

Key Considerations

• If MRSA is suspected based on local prevalence or risk factors, consider clindamycin 300-450 mg three times daily or trimethoprim-sulfamethoxazole (TMP-SMX) DS twice daily instead 1.
• For severe cases or those with systemic symptoms (fever, significant swelling, lymphangitis), intravenous antibiotics may be necessary 1.
• While taking antibiotics, elevate the affected hand, apply warm compresses, and mark the border of the redness with a pen to monitor progression.
• Seek immediate medical attention if the infection worsens despite antibiotics, spreads beyond the marked border, or if you develop fever, increasing pain, or red streaks extending up the arm, as these may indicate a worsening infection requiring more aggressive treatment 1.

Additional Guidance

• The 2014 IDSA guideline recommends that patients should receive antibiotics for uncomplicated cellulitis but that clinicians should consider extending treatment if the infection has not improved after 5 days 1.
• The more recent 2019 National Institute for Health and Care Excellence (NICE) guideline recommends a course of 5 to 7 days 1.
• A systematic review included 1 RCT that found no significant differences in clinical outcomes between 5 or 10 days of therapy with a fluoroquinolone (levofloxacin) 1.

From the FDA Drug Label

Prescribing dicloxacillin sodium capsules in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

The antibiotic to be given for cellulitis to the left hand is dicloxacillin.

• Key points:
  • Dicloxacillin is a penicillinase-resistant penicillin.
  • It should only be used to treat bacterial infections.
  • The patient should be told to take the entire course of therapy prescribed, even if fever and other symptoms have stopped.
  • Bacteriologic studies to determine the causative organisms and their susceptibility to the penicillinase-resistant penicillins should be performed. 2

From the Research

Antibiotic Treatment for Cellulitis

• The majority of non-purulent, uncomplicated cases of cellulitis are caused by β-hemolytic streptococci or methicillin-sensitive Staphylococcus aureus 3.
• Appropriate targeted coverage of this pathogen with oral antibiotics such as penicillin, amoxicillin, and cephalexin is sufficient 3.
• For cellulitis without purulent drainage, β-hemolytic streptococci are presumed to be the predominant pathogens 4.
• Cephalexin is a commonly prescribed antibiotic for the treatment of uncomplicated cellulitis 5, 6, 4.

Considerations for MRSA Coverage

• The role of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in non-purulent cellulitis is less clear 7.
• Published clinical practice guidelines suggest that CA-MRSA plays only a minor role in non-purulent cellulitis and that initial treatment should be primarily directed at β-hemolytic streptococci 7.
• Studies have shown that the addition of trimethoprim-sulfamethoxazole to cephalexin did not improve outcomes overall or by subgroup for patients with uncomplicated cellulitis 6, 4.

Treatment Options

• Cephalexin alone may be sufficient for the treatment of uncomplicated cellulitis 6, 4.
• Trimethoprim-sulfamethoxazole may be considered for patients with a high risk of CA-MRSA infection or in areas with a high prevalence of CA-MRSA 5.
• Penicillin and amoxicillin are also effective treatment options for uncomplicated cellulitis 3.