Is impetigo (impetigo contagiosum) on multiple sites of the scalp and behind the ear considered an extensive infection in the absence of fever (afebrile)?

Treatment of Impetigo on Multiple Sites of Scalp and Behind the Ear

Impetigo on multiple sites of the scalp and behind the ear is considered extensive infection requiring oral antibiotic therapy, even in the absence of fever. 1, 2

Clinical Assessment of Extensive Impetigo

• Impetigo is classified as extensive when it involves multiple sites or large areas, making topical therapy impractical 1, 2
• The presence of multiple lesions across the scalp and behind the ear qualifies as extensive disease requiring systemic treatment, regardless of the absence of fever 3
• Impetigo is a highly contagious bacterial skin infection affecting the superficial layers of the epidermis, most commonly caused by Staphylococcus aureus and/or Streptococcus pyogenes 4

Treatment Algorithm for Extensive Scalp Impetigo

First-Line Treatment: Oral Antibiotics

• For extensive impetigo involving multiple sites on the scalp, oral antibiotics are the recommended first-line treatment 1, 2
• Recommended oral antibiotics for methicillin-susceptible S. aureus (MSSA) include:
  • Dicloxacillin (250 mg four times daily for adults) 2
  • Cephalexin (250-500 mg four times daily for adults) 2
  • First-generation cephalosporins 1

Alternative Oral Antibiotics

• For suspected methicillin-resistant S. aureus (MRSA), consider:

  • Clindamycin (300-450 mg three times daily for adults) 2
  • Trimethoprim-sulfamethoxazole (TMP-SMX) 2
  • Doxycycline (not for children under 8 years) 2

• Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 2, 5

Duration of Treatment and Follow-up

• Oral antibiotics should be administered for 5-10 days 2
• Re-evaluation is necessary if no improvement is seen after 48-72 hours of therapy 2
• Complete the full course of prescribed antibiotics even if symptoms improve quickly 1

Additional Management Measures

• Keep lesions covered with clean, dry bandages to prevent spread 2
• Maintain good personal hygiene 2
• Consider obtaining cultures of the lesions if there is treatment failure or MRSA is suspected 2

Common Pitfalls to Avoid

• Topical antibiotics alone are insufficient for extensive impetigo involving multiple sites 1, 2
• Using penicillin as monotherapy is ineffective due to inadequate S. aureus coverage 2, 5
• Discontinuing antibiotics prematurely when symptoms improve can lead to treatment failure and complications 1
• Failing to consider MRSA in cases of non-response to first-line therapy 1, 2

Special Considerations

• Adjust oral antibiotic dosing by weight for children 2
• Tetracyclines (doxycycline, minocycline) should not be used in children under 8 years of age 2
• Consider local antibiotic resistance patterns when selecting empiric therapy 4, 5