Insect Repellents: Types, Safety, and Proper Use

A guide to different insect repellents, their effectiveness, and safe application practices.

1. Insect Repellants Dr. Shivankan Kakkar , MD

2. Introduction to Insect Repellents Definition: Substances applied to skin, clothing, or surfaces to deter insects. Primary Use: Protection against mosquitoes and other pests (flies, fleas, cockroaches). Importance: Reduces risk of mosquito-borne diseases like malaria and dengue. Dr. Shivankan Kakkar, MD 2

3. Mechanism of Action Host Attraction: Mosquitoes use smell to locate hosts (human body odour & CO₂). Repellent Action: Interact with insect odorant receptors to deter mosquitoes. Efficacy Assays: Host-attraction inhibition and other methods to measure effectiveness. Dr. Shivankan Kakkar, MD 3

4. Common Synthetic Repellents DEET (N,N-diethyl-m-toluamide) Widely used for over 70 years. Effective for 1-6 hours. Absorbed through skin; may cause irritation. Picaridin Synthetic equivalent of piperine . Offers 6-12 hours of protection; less irritation compared to DEET. Pyrethroids ( Prallethrin , Transfluthrin ) Fast-acting, effective in vapor form. Potential side effects include nausea and dizziness. Dr. Shivankan Kakkar, MD 4

5. Natural Repellents Essential Oils: Generally less effective and shorter lasting. Common Types: Citronella Oil: Effective for ~2 hours. Lemon-Eucalyptus Oil: Active against mosquitoes. Neem Oil: Effective for up to 12 hours; has a strong odor . Safety: Typically considered nontoxic for children and pregnant women. Dr. Shivankan Kakkar, MD 5

6.  Safety & Precautions Side Effects of DEET: Skin irritation, insomnia, mood disturbances. Neurotoxicity and seizures in rare cases. Usage Tips: Avoid contact with eyes/mucous membranes. Reapply as needed, but avoid overuse. Dr. Shivankan Kakkar, MD 6