Insect Repellents

Introduction

Most insect bites cause itchy red lumps or bumps that appear on the skin. This causes scratching, which increases the risk of bleeding, scarring and infection. Mosquito bites may also transmit infections such as Dengue and Zika Virus. There are various insect repellents in the market that can protect you from mosquito bites and mosquito-borne diseases.

What are the different types of mosquito repellents?

• There are many types of insect repellents which may come in forms like sprays, lotions, wipes, patches, bands and even candles.
• The common ingredients found in mosquito repellents are DEET (N,N-Diethyl-meta-toluamide), Picaridin, IR3535 (Ethyl butylacetylaminopropionate) and Oil of Lemon Eucalyptus. These ingredients provide reasonably long-lasting protection. Other ingredients include citronella, lemongrass, tea tree oil and natural essential oil.
• According to the National Environment Agency (NEA), DEET, Picaridin and IR3535 are more effective and have longer mosquito-repelling effects than “natural” repellents that use plant-based extracts, such as citronella, eucalyptus and other essential oils.
• DEET is one of the most effective and best studied repellents to repel mosquitos. The higher the concentration of DEET (20% or more is recommended), the longer the duration of protection.

How should I apply mosquito repellents?

It is advised to follow the instructions on the product labels. Most products can be applied directly on the skin.

• For sprays, hold the bottle about 15cm away from the skin or clothing and spray in a slow sweeping motion. Do not spray into the air.
• For patches, stick them on the clothing or on any surface close to the body instead of directly onto skin, to prevent skin irritation.
• If you need to use sunscreen, apply sunscreen first followed by repellent.

What precautions should I take when using these mosquito repellents?

• Use sufficient repellent to cover exposed skin or clothing. Spread evenly and reapply when necessary.
• Do not apply onto cuts, wounds, burns or irritated skin.
• Do not spray directly onto the face, especially to the eyes and mouth. To apply on the face, apply on the hands first and rub on evenly. Apply sparingly around the ears.
• If the product comes into contact with the eyes, immediately wash them under a running tap.
• Keep repellent away from children. Apply onto the adult’s hands first before applying on them. Avoid applying on children’s hands as they may swallow by accident or there may be exposure to the eyes.
• After returning indoors, wash the applied areas thoroughly with soap and water. Wash the clothing before wearing again, to remove any repellent residue.
• If skin rash or irritation occurs, discontinue use and consult a doctor if necessary.

What are other important points that I need to take note of?

• Duration of protection may be reduced by sweating or washing. Check the product label for how often the product needs to be reapplied.
• For high risk areas, more than one type of repellent can be used (e.g. patch and spray)
• Most repellents can only be used on children more than 2 months old. For infants less than 2 months old, use a mosquito netting and allow a tight fit over their carrier.
• According to the United States Environmental Protection Agency (EPA), pregnant or breastfeeding women can use any EPA-registered product, including those containing Picaridin, IR3535 and DEET.

What are some rare but serious side effects that I need to see a doctor immediately?

The symptoms of a drug or chemical allergy include one or more of the following:

• Swollen face, eyes, lips and/or tongue
• Difficulty in breathing
• Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop using the product and see your doctor immediately.

What are the other alternatives to reduce bites?

General protective measures include:

• Limiting time spent outdoors, especially during dawn and dusk where most mosquitoes are active
• Wearing light coloured, long-sleeved clothing and pants to minimize skin exposure
• Installing mosquito bed nets, screens on windows and doors, or using air conditioning at home to keep mosquitoes out
• Applying Permethrin-containing products to bed nets and clothing for added protection
• For more information on how to prevent mosquito breeding at your home, please visit NEA’s website at https://www.nea.gov.sg/dengue-zika/stop-dengue-now