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Mosquito Repellant

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Mosquito Repellant, Diethyltoluamide, DEET

  • See Also
  1. Prevention of Vector-borne Infection
  2. Vector-Borne Infection
  3. Pesticide
  4. Permethrin
  • Epidemiology
  1. DEET used by 200 Million persons worldwide
  2. Used by 38% of U.S. population
  3. Only 30 adverse events reported between 1966-1997
  • Indications
  1. Prevention of Vector-borne Infection in endemic areas
  2. Prevention of Insect Bite
  • Mechanism
  1. DEET concentration above 10% lasts longer, not better
  2. Insect repellents work as a chemical barrier
    1. Block Mosquito's detection of prey
  • Adverse Effects (DEET)
  1. General
    1. Concentration >15% associated with adverse effects
    2. Most DEET preparations safe
  2. Local Effects
    1. Mild skin irritation
    2. Corneal irritation
    3. Mucosal irritation
  3. Serious effects with excessive use under Occlusion
    1. Neurologic
      1. CNS Depression
      2. Seizures
    2. Cardiovascular
      1. Hypotension
      2. Tachycardia
  4. Other effects: Gastrointestinal
    1. Nausea and Vomiting with ingestion
  • Efficacy
  1. DEET is effective against Mosquitoes, ticks, lice, fleas
  • Technique
  1. Apply every 1-2 hours during exposure
  2. Apply Sunscreen before (under) Insect repellent
  3. Do not apply repellent around eyes and mouth
  4. Concentration up to 30% may be used over age 2 months
  • Preparations
  1. DEET concentration affects duration of activity, not the effectiveness
    1. Duration 2 hours: 6% DEET
    2. Duration 2-3 hours: 10% DEET
    3. Duration 3-5 hours: 20% DEET
    4. Duration 5-6 hours: 30% DEET
  2. Longest acting and most effective agents
    1. Ultrathon (34% DEET): 12 hour protection claimed
    2. Deep Woods Off (23% DEET): 200-360 minutes protection
    3. Sawyer Controlled Release (20% DEET): 180-325 minutes
      1. Slowly releases DEET in response to sweating
      2. Lower toxicity due to slow release
    4. Off Skintastic (6.6% DEET): 90-170 minutes protection
  3. Moderate duration of activity and effectiveness
    1. Avoid combined Insect repellent with Sunscreen (Sunscreen needs more frequent application)
    2. Bite Blocker Kids (2% Soybean oil): 16-195 minutes
    3. Off Kids Skintastic (4.75% DEET): 45-120 minutes
    4. Skin-So-Soft Bug Guard Plus (7.5% IR3535): 10-60 min
  4. Shortest duration and minimal activity (<5 minutes)
    1. Natrapel (Citronella)
    2. Herbal Armor (Citronella)
    3. Green Ban for People (Citronella)
    4. Buzz Away (Citronella)
    5. Skin-So-Soft Bug Guard (Citronella)
    6. Skin-So-Soft Bath Oil
    7. Skin-So-Soft Moisturizing Suncare (Citronella)
    8. Gone Original Wristband (9.5% DEET)
    9. Repello Wristband (9.5% DEET)
    10. Gone Plus Repelling Wristband (Citronella)
  5. Alternatives to DEET with similar efficacy to DEET 10%
    1. Picaridin 7% (e.g. Cutter Advanced)
      1. Less irritation and better smell and feel than DEET
      2. Duration of effect is 2 hours
    2. Lemon Eucalyptus Oil 30%
      1. Do not use in children under age 3 years (not studied)
  • Precautions
  1. Limit DEET concentration to less than 30 to 35%
  2. CDC recommends DEET 35% for Malaria prevention
  • Management of toxicity
  1. Skin Decontamination
  2. Seizure management with Benzodiazepines
  3. Supportive management
  • References
  1. (2005) Prescriber's Letter p. 36
  2. Fradin (1998) Ann Intern Med 128(11):931-40 [PubMed]
  3. Fradin (2002) N Engl J Med 347:13-8 [PubMed]