Arthropod and parasitic antibiotics

Antibiotics by diagnosis

For antibiotics by organism see Microbiology (Main)

Lice

Over the Counter (OTC)

  • Permethrin 1% lotion shampoo (if >2 months old)[1]
    • Wash hair with non-conditioned shampoo
    • Apply Permethrin for 10 min and rinse
    • Repeat on day 9
  • Pyrethrin lotion
    • Apply to affected areas and wash off after 10 min
    • Repeat in 7 days

Prescription

Reserved for failed OTC treatment

  • Spinosad 0.9% topical suspension (if >6 months old)
    • Apply to scalp and air and wash off after 10 min.
    • Repeat in 10 days
  • Malathion 0.5% lotion (if >6 years old)
    • Applied to affected areas and wash after 8 hrs
    • Repeat in 7 days
  • Benzyl Alcohol 5% lotion (> 6 months old)
    • Apply to dry hair and wash off after 10 min
    • Repeat in 7 days
  • Ivermectin 400mcg/kg PO
    • Once on day 1 THEN once in 7 days
    • Reserved for patients failing topical treatment
  • Lindane therapy
    • Only consider if patient has failed two prior prescription treatments
    • Avoid in children <50 kg due to seizure association

Eyelash Infestation

  • Apply ophthalmic petroleum jelly q12hrs x 10 days

Pediatrics <2yo

  • Wet combing is an alternative to medical therapy

Pinworm

Treatment targeted against Enterobius vermicularis

  • Mebendazole 100mg PO once THEN repeat in 2 weeks OR
  • Albendazole 400mg PO once (100mig if < 2yo) THEN repeat in 2 weeks OR
  • Pyrantel Pamoate (Pin-x) 11mg/kg (max 1g) THEN repeat in 2 weeks
    • Recommended for pregnant patients

Scabies

General Care

  • Wash all linens/clothes in hot water or bag bulky items and keep sealed for 2wks
  • Pruritus may continue for weeks despite successful elimination of infestation
    • Consider steroids for symptom relief

Adults

  • Permethrin 5% cream for all family members[2]
    • Apply from neck down
    • Leave on for 8-12hr before washing off
    • Has 95-98% success rate, may reapply in 1-2wks if incomplete effect
  • Ivermectin 200 mcg/kg may be necessary for severe infection
    • Also viable option in adolescent or adult with insecure social situation
    • Success rate 70%, increases if give repeat dose 2wks after
    • Contraindicated in lactating women and children < 15kg

Infants

  • Permethrin 5% is FDA approved for > 2 months of age although still recommended for neonatal scabies[3]
    • May require application head to toe (avoid mucus membranes)
    • Leave on for 8-12 hours, then wash off

Avoid

  • Lindane - effective treatment but associated with potential for toxic manifestations (seizures, neurotoxicity)
    • Reserved for refractory cases

References

  1. Devore CD and Schutze G. Head Lice. Pediatrics. 2015; 135(5) e1355-e1365.
  2. Strong M. Johnstone P. Interventions for treating scabies. Cochrane Database Syst Rev. 2007;(3):CD000320
  3. Subramaniam S. Rutman MS. Wnger JK. A papulopustular, vesicular, crusted rash in a 4-week old neonate. Pediatric Emergency Care. 2013;29:1210-1212