What is the treatment for a rash that appears after a streptococcal (strep) infection?

Treatment for Post-Streptococcal Rash

For rashes that appear after streptococcal infections, supportive care with antihistamines and antipyretics is typically sufficient, as these rashes are often non-infectious, self-limiting manifestations that don't require additional antibiotic therapy. 1

Understanding Post-Streptococcal Rashes

• Post-streptococcal rashes are immunologically mediated reactions that can appear after adequate treatment of the streptococcal infection 1
• These rashes may be scarlatiniform (diffuse, erythematous, sandpaper-like) in appearance 1
• They typically develop after the acute infection has been adequately treated with antibiotics 1
• The rash is not typically a sign of treatment failure or ongoing infection if the patient has completed an appropriate course of antibiotics 1

Management Approach

Primary Treatment

• Supportive care is the mainstay of treatment for post-streptococcal rashes 1
• Antihistamines (such as cetirizine, loratadine) can help relieve itching and discomfort 1
• Antipyretics/analgesics (acetaminophen, NSAIDs) can be used for associated discomfort or fever 1
• Skin moisturizers may help with dryness and irritation 1

When to Consider Additional Antibiotic Treatment

• Additional antibiotics are generally not needed if:

  • The patient completed a full course of appropriate antibiotics for the initial streptococcal infection 1
  • The rash appears after treatment has been completed 1
  • There are no signs of ongoing infection 1

• Consider additional antibiotics only if:

  • The initial treatment course was incomplete (less than 10 days for penicillin/amoxicillin) 1, 2
  • There are signs of persistent or recurrent streptococcal infection 1
  • Secondary bacterial infection of the rash is suspected 1

Antibiotic Options (If Needed)

• First-line: Penicillin V or amoxicillin for 10 days 1, 2

  • Penicillin V: Children 250 mg 2-3 times daily; Adults 250 mg four times daily or 500 mg twice daily 1
  • Amoxicillin: 50 mg/kg once daily (maximum 1,000 mg) or 25 mg/kg twice daily (maximum 500 mg per dose) 1

• For penicillin-allergic patients: 1

  • Cephalexin 20 mg/kg twice daily (maximum 500 mg per dose) for 10 days (if no immediate hypersensitivity to penicillin)
  • Clindamycin 7 mg/kg three times daily (maximum 300 mg per dose) for 10 days
  • Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days
  • Clarithromycin 7.5 mg/kg twice daily (maximum 250 mg per dose) for 10 days

Important Clinical Considerations

• A full 10-day course of antibiotics is recommended for streptococcal pharyngitis to prevent complications like acute rheumatic fever 1, 2
• Post-streptococcal rashes are different from active streptococcal skin infections like impetigo, which require specific antibiotic treatment 1
• Urticaria can sometimes be associated with streptococcal infections and may require antihistamine treatment 3
• Monitor for signs of more serious complications like toxic shock syndrome (hypotension, diffuse erythematous rash, organ dysfunction) which requires immediate medical attention 4, 5
• For perianal streptococcal dermatitis, a longer treatment course (14-21 days) may be needed 6

When to Seek Further Medical Attention

• Worsening rash despite supportive care 1
• Development of systemic symptoms (high fever, hypotension) 4
• Signs of secondary bacterial infection (increasing pain, purulence, warmth) 1
• Development of new symptoms suggesting post-streptococcal complications 1