Doxycycline for Cellulitis

Based on "Principles and Practice of Infectious Diseases"
written by John E. Bennett, MD

Cellulitis is a skin and soft-tissue infection resulting from entry of bacteria via break in the skin barrier 1. Generally cellulitis involves the dermis and subcutaneous tissue.

The condition presents as the acute and progressive onset of a red, painful, swollen and tender area of skin. Cellulitis usually affects the lower extremities, but it can affect other parts of the body.

doxycycline for cellulitis treatment Infographic

Cellulitis Causes

The most common infective organisms causing cellulitis:

Staphylococcus aureus
Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is suspected in the presence purulent cellulitis, wound infection, penetrating trauma, if there is a known outbreak or local prevalence is high.
Streptococcus pyogenes

Less common causative organisms include:

Streptococcus pneumoniae
Haemophilus influenzae
Gram-negative bacilli
Anaerobes

Antibiotic Selection

Selection of antibiotic for cellulitis treatment is based on the presence or absence of purulence.

If cellulitis is accompanied by purulent drainage, there is a great likelihood, that infection is caused by MRSA.

Cellulitis without abscess, ulcer, or purulence is usually due to Streptococcus species. MRSA very rarely causes non-suppurative cellulitis2.

Typical mild non-purulent cellulitis is treated with3:

penicillin
amoxicillin
amoxicillin/clavulanate
dicloxacillin
cephalexin

Doxycycline Efficacy for Cellulitis

Doxycycline is effective and FDA-approved for skin and soft-tissue infections caused by Staphylococcus aureus.
Doxycycline is an oral antibiotic option for treating skin and soft-tissue infections caused by community-associated MRSA.
Doxycycline has poor activity against Group A β-hemolytic streptococci. So to coverage both streptococci and CA-MRSA doxycycline is used in combination with amoxicillin, penicillin, or cephalexin3.

Doxycycline Dosage for Cellulitis

Community-acquired MRSA cellulitis:
Doxycycline 100 mg twice daily for 7-10 days.

To cover Group A Streptococcus and CA-MRSA:Doxycycline 100 mg twice daily
plus
one of the following antibiotics:

Penicillin 500 mg 4 times daily
Cephalexin 500 mg 4 times daily
Amoxicillin 500 mg 3 times daily

Alternatives to Doxycycline for MRSA cellulitis

Clindamycin3
Trimethoprim/sulfamethoxazole (TMP/SMX)3

References

1. Chira S, Miller LG. Staphylococcus aureus is the most common identified cause of cellulitis. Epidemiol Infect. 2010 Mar;138(3):313-7.
2. Eells SJ, Chira S, David CG, Craft N, Miller LG. Non-suppurative cellulitis: risk factors and its association with Staphylococcus aureus colonization in an area of endemic community-associated methicillin-resistant S. aureus infections. Epidemiol Infect. 2011 Apr;139(4):606-12.
3. Practice Guidelines for the Diagnosis and Management of Skin and Soft Tissue Infections: 2014 Update by the Infectious Diseases Society of America

Published: July 28, 2019 by eMedExpert staff
Last updated: July 28, 2019