What is the first-line antibiotic choice for infected psoriasis?

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Last updated: June 16, 2025View editorial policy

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From the Guidelines

The first-line antibiotic choice for infected psoriasis is typically a beta-lactam antibiotic such as flucloxacillin (500mg four times daily for 7-14 days) or dicloxacillin (500mg four times daily for 7-14 days). These antibiotics are effective against Staphylococcus aureus, which is the most common bacterial pathogen in infected psoriatic plaques. For patients with penicillin allergy, alternatives include clindamycin (300-450mg four times daily) or first-generation cephalosporins if the allergy is not severe. Treatment should be guided by clinical response, and cultures should be obtained in severe or non-responsive cases to identify the specific pathogen and its antibiotic sensitivities. Topical antibiotics like mupirocin may be used for limited superficial infection, but systemic antibiotics are preferred for more extensive involvement. It's essential to continue psoriasis treatments concurrently as controlling the underlying inflammation helps resolve the infection. The choice of antibiotic may need adjustment based on local resistance patterns, and MRSA coverage with trimethoprim-sulfamethoxazole or doxycycline should be considered in high-risk patients or areas with high MRSA prevalence 1.

Some key points to consider when treating infected psoriasis include:

  • The importance of treating the underlying psoriasis to help resolve the infection
  • The need to adjust antibiotic choice based on local resistance patterns and patient-specific factors
  • The potential for MRSA infection and the need for coverage with trimethoprim-sulfamethoxazole or doxycycline in high-risk patients or areas
  • The use of topical antibiotics for limited superficial infection, but preference for systemic antibiotics for more extensive involvement
  • The consideration of alternative antibiotics, such as clindamycin or first-generation cephalosporins, in patients with penicillin allergy.

It is also important to note that the treatment of infected psoriasis should be individualized based on the specific patient's needs and circumstances, and that consultation with a dermatologist or other specialist may be necessary in complex or severe cases 1.

From the Research

Infected Psoriasis Antibiotic Choice

  • The first-line antibiotic choice for infected psoriasis is not explicitly stated in the provided studies, but we can look at the treatment options for skin and soft-tissue infections caused by Staphylococcus aureus and Streptococcus pyogenes, which are common in psoriasis patients.
  • According to 2, cephalexin is an effective antibiotic for the treatment of streptococcal and staphylococcal skin infections, with cure rates of 90% or higher.
  • 3 suggests that systemic antibiotics like cloxacillin, erythromycin, azithromycin, or cephalexin should be used for widespread or severe impetigo and ecthyma.
  • For methicillin-susceptible S. aureus (MSSA) infections, penicillinase-resistant penicillins (flucloxacillin, dicloxacillin) are the antibiotics of choice, but first-generation cephalosporins (cefazolin, cephalothin, and cephalexin) and clindamycin have important therapeutic roles in less serious MSSA infections, as stated in 4.
  • In the context of psoriasis, 5 mentions that macrolides and rifampin showed a decrease in psoriasis area and severity index score in plaque-type psoriasis, while penicillin revealed no statistically significant improvement in guttate psoriasis.
  • Minocycline is often preferred to trimethoprim-sulfamethoxazole or doxycycline for the treatment of community-acquired meticillin-resistant Staphylococcus aureus skin and soft-tissue infections, as stated in 6.

Treatment Options

  • Cephalexin is a viable option for infected psoriasis, especially for streptococcal and staphylococcal skin infections 2, 3.
  • Macrolides and rifampin may be beneficial for psoriasis control, as they showed a decrease in psoriasis area and severity index score in plaque-type psoriasis 5.
  • Minocycline is a reliable option for the treatment of uncomplicated community-acquired MRSA skin and soft-tissue infections 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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