What are over-the-counter (OTC) treatment options for lice?

Over-the-Counter Treatment Options for Head Lice

For head lice treatment, permethrin 1% cream rinse is the first-line over-the-counter option, with a second application needed 7-10 days after the first treatment to kill newly hatched lice. 1

First-Line OTC Treatment Options

Permethrin 1% Cream Rinse

• Apply thoroughly to dry hair
• Allow product to remain for 10 minutes (no longer)
• Rinse with warm water
• A second treatment must be done within 7-10 days to kill newly hatched lice 1, 2
• Efficacy: Studies show 99% effectiveness when properly applied 3, though more recent research suggests possible resistance with efficacy rates of 78-83% 4, 5

Pyrethrin-Based Products

• Similar application process to permethrin
• Apply to dry hair, leave for 10 minutes, then rinse
• Requires a second treatment in 7-10 days 2
• Often combined with piperonyl butoxide for enhanced effectiveness

Mechanical Removal Methods

Wet Combing

• Use a fine-toothed lice comb on damp hair
• Comb in sections, starting at the scalp
• Clean comb frequently between passes
• May be used alone or as an adjunct to medication 1
• Note: Research shows combing alone by non-professionals has limited efficacy 4

Treatment Protocol

1. Confirm diagnosis: Find a live louse using a fine-toothed comb 1
2. Apply treatment: Use permethrin 1% or pyrethrin-based product as directed
3. Follow-up treatment: Apply second treatment 7-10 days after first 1, 2
4. Environmental measures:
   • Machine wash clothing, bedding, and hats in hot water (above 130°F/54°C)
   • Use hottest dryer setting for at least 20 minutes
   • Soak combs and brushes in hot water for at least 10 minutes
   • Vacuum carpets, furniture, and car seats 1, 2

Important Considerations

• Treatment failure signs: If live lice are found after completing the full treatment course (including second application)
• Common pitfalls:
  • Inadequate application of product
  • Failure to apply second treatment
  • Misidentifying dandruff or hair debris as lice/nits
  • Reinfestation from untreated contacts 1

Special Populations

• Children: The American Academy of Pediatrics recommends permethrin 1% as first-line treatment for children 1
• Pregnant/nursing women: Permethrin 1% is generally considered safe; consult healthcare provider

When to Seek Medical Care

• Multiple failed OTC treatments
• Severe scalp irritation or secondary infection
• Infestation in children under 2 years of age
• Presence of crusting or weeping suggesting secondary infection 1

Prevention

• Avoid head-to-head contact
• Don't share personal items like combs, hats, or headphones
• Regularly examine family members using a lice comb during outbreaks 1, 2