Infectious Disease Case

A father has just moved to the area and brings his 1-month-old son, 3-year-old daughter, and 7-year-old son for their well-child checks.
Infectious Disease Case

It is May and all are healthy and doing well. He has heard from neighbors that there are ticks and mosquitos in the area that harbor infectious diseases. He asks you for advice on how to prevent both tick- and mosquito-borne infections.

You suggest that he should:

A. Avoid letting the children play outside in the evening time.

B. Apply DEET to exposed skin of all the children before they go outside.

C. Apply permethrin to exposed skin of all the children before they go outside.

D. All of the above.

E. None of the above.

The correct answer is “E.” A broad range of bacterial, viral, and parasitic infections in the United States have tick and mosquito vectors. The type of infection depends on geography, but examples include Rocky Mountain spotted fever, ehrlichiosis, Lyme disease, babesiosis, Colorado tick fever, West Nile virus, and La Crosse virus. Diseases thought to be more associated with tropical locales, such as dengue and chikungunya, are now starting to appear in some parts of the southern United States. In the United States mosquitoes often are more active at dawn and dusk, so avoiding outside activities at this time may decrease risk of infection. However, many species of mosquitoes are active and bite during the day, making transmission of infection possible at any time. Avoiding evening activity would not prevent tickborne infection. There are multiple repellants available for use to decrease tick and mosquito exposure. Permethrin can be used to impregnate clothing and will repel ticks and mosquitoes, but should not be applied directly on the skin due to risk of absorption. DEET (N,N-diethyl-meta-toluamide) is available in various concentrations and repels both ticks and mosquitoes. It should be applied to exposed skin. As a general rule, the higher the concentration of DEET, the longer lasting the effect, and the greater the risk of systemic absorption and toxicity. DEET is not recommended for use in children younger than 2 months of age. For children 2 months of age and older, DEET concentrations of 10% to 30% are recommended. Picaridin is also available for use as a tick and mosquito repellent. The Environmental Protection Agency (EPA) does not recommend its use in children younger than 3 years of age. Oil of lemon and eucalyptus may repel ticks and mosquitoes, but neither has undergone formal evaluation and their use is not recommended for children younger than age 3. Repellents should not be applied to the hands as children often put their hands in their mouth, increasing the risk of systemic absorption. Tick exposure can be limited by exercising care in tick-prone areas such as woods and heavy brush. Long sleeves and pants can limit exposure. Children should be regularly checked for ticks after playing in these areas. One solution might be to avoid the outdoors and take supplemental vitamin D to offset the lack of sunlight exposure.


Question & Explanation: Peterson AR, Wood KE. Pediatrics Examination and Board Review. New York, NY: McGraw-Hill Education; 2017.

Photo: Prose NS, Kristal L. Weinberg's Color Atlas of Pediatric Dermatology, 5e; 2017