Is doxycycline (DOXY) an appropriate antibiotic (abx) treatment for cellulitis of the arm?

Doxycycline for Cellulitis of the Arm

Doxycycline is an appropriate antibiotic treatment for cellulitis of the arm, particularly when MRSA is suspected or in patients with beta-lactam allergies. 1

First-line Treatment Options for Cellulitis

The treatment of cellulitis depends on whether it is purulent or non-purulent:

Non-purulent Cellulitis

• First-line therapy: Beta-lactam antibiotics (e.g., cephalexin, dicloxacillin) targeting beta-hemolytic streptococci 1, 2
• Duration: 5-6 days is typically sufficient if clinical improvement occurs 2

Purulent Cellulitis (abscess, furuncle, or carbuncle with surrounding cellulitis)

• First-line options (all rated AII evidence level) 1:
  • Clindamycin: 300-450 mg PO TID
  • TMP-SMX: 1-2 DS tablets PO BID
  • Doxycycline: 100 mg PO BID
  • Minocycline: 200 mg x1, then 100 mg PO BID
  • Linezolid: 600 mg PO BID

When to Choose Doxycycline

Doxycycline is particularly appropriate in the following scenarios:

• When MRSA coverage is needed 1
• In patients with beta-lactam allergies
• For purulent cellulitis 1

Important Considerations for Doxycycline Use

• Contraindications: Not recommended for children under 8 years of age and is pregnancy category D 1
• Coverage limitations: While doxycycline has good in vitro activity against CA-MRSA, its activity against beta-hemolytic streptococci is not well-defined 1
• Dosing: Adequate weight-based dosing is important for successful treatment 3

When to Consider Alternative Antibiotics

Consider alternatives to doxycycline in these situations:

1. Non-purulent cellulitis (beta-lactams preferred) 1, 2
2. Severe or extensive disease with systemic illness (IV therapy may be needed) 1
3. Children under 8 years of age or pregnant women 1
4. When beta-hemolytic streptococci are the likely causative organisms 4

Treatment Failure Considerations

If no improvement occurs within 48-72 hours:

• Reassess diagnosis
• Consider changing antibiotics
• Evaluate for complications or alternative diagnoses 2
• Ensure adequate dosing (inadequate dosing is independently associated with clinical failure) 3

Prevention of Recurrent Cellulitis

For patients with recurrent cellulitis (3-4 episodes per year):

• Identify and treat predisposing conditions (edema, obesity, eczema, venous insufficiency, toe web abnormalities) 1
• Consider prophylactic antibiotics such as oral penicillin or erythromycin BID for 4-52 weeks, or intramuscular benzathine penicillin every 2-4 weeks 1, 5

Doxycycline is a reasonable option for treating cellulitis of the arm, particularly when MRSA is suspected, but clinicians should be aware of its limitations regarding beta-hemolytic streptococcal coverage and contraindications in certain populations.