Repellents as part of prevention

Repellents are effective preparations that repel various types of biting insects, such as ticks, mosquitoes, fleas and others.

Protection is important especially because these insects can pose a significant risk of transmitting serious diseases (in our conditions, these are mainly tick-borne encephalitis and Lyme disease).

Repellents are most often found in the form of sprays or atomizers. There are also various gels, creams, bracelets, patches, etc. Depending on their purpose, they can be used on the skin or clothing, or both.

In general, a higher concentration of the active ingredient prolongs the duration of action, but the intensity remains unchanged.

The effectiveness of the repellent depends on the type and composition of the product, environmental conditions and human behavior. Therefore, the application must be repeated according to the manufacturer's instructions (as a rule, we do not apply to damaged skin and around the eyes or mouth).

In repellents for adults, we most often encounter:

• DEET (N, N – diethyltoluamide) in a concentration of 5–100 % is safe for most people, including children, when used correctly; concentrations up to 30 % can be used in children from 2 months, pregnant and breastfeeding women; concentrations above 30 % provide protection for about 5 hours in adults; disadvantage: distinct odor, damages plastics and synthetic materials,
• Pyrethroids (permethrin/deltamethrin) at a concentration of 0.5 % are insecticides and have a broader spectrum of action than other substances; they are commonly used to impregnate outdoor clothing, footwear, tents and mosquito nets.

In repellents intended for children or individuals with sensitive skin, the active ingredient often used (with lower irritation while having comparable repellent properties as DEET) is:

• Icaridin – is a modern alternative to DEET, odorless, used in concentrations
  10-30 %, is a highly effective repellent with good skin tolerance, does not damage plastics or textiles.
• IR 3535 (Insect Repellent 3535, ethyl ester-3-[N-butyl-N-acetyl]-aminopropionic acid, EBAAP) – is valued for its high safety, low irritation and good compatibility with materials; it is used in a concentration of 10-30 %, it is odorless.
• Eucalyptus oil – contains citriodiol (PMD) as the main active ingredient, due to the risk of acute allergic reaction it is only suitable for children from 3 years of age.

To repel insects, natural repellents (strongly aromatic substances such as citronellol, geraniol, menthol, etc.) or B1 (thiamine) can also be used as an additional means of repelling insects. Freely available according to the web portal of the Czech Chamber of Pharmacists for the public, Lékárnické kapky, 30.6.