CLINICAL INQUIRIESIs DEET safe for children?
Zachary A. Flake, MD; Jose R. Hinojosa, MD
Fort Collins Family Medicine Residency Program, Fort Collins, ColoMarcy Brown, MLS
Forbes Regional Hospital, Monroeville, Pa

EVIDENCE-BASED ANSWER

Reported evidence suggests that DEET use is safe for children
older than 2 months, with only very rare incidence of major
adverse effects (strength of recommendation [SOR]: C).
Typically, a topical concentration between 10% and 30%
should be used (SOR: C). Increasing DEET concentration does
not improve protection, but does increase the duration ofaction (SOR: A).

C L I N I C A L C O M M E N TA RYCounsel parents to take 3 steps to prevent bites —avoid, cover up, and repel
The emergence of West Nile virus has heightened awarenessof mosquitoes, and I often field questions about how toprotect children from bites. I counsel parents to take 3 steps
to prevent bites—avoid, cover up, and repel. Mosquitoes areactive at dawn and dusk, so staying indoors during thesetimes is protective. Covering up with long sleeves, pants, andsocks protects from most bites. Lastly, DEET repellent
protects exposed areas from mosquitoes. Lotions make iteasier to apply DEET to children. Commonly, parents express
fear of DEET due to media reports. This review will help meease their fears.

Paul Crawford, MD

USAF-Eglin Family Practice Residency, Eglin Air Force Base, Fla■ Evidence summary

The increasing prevalence of mosquitoborne diseases, including West Nile virus,
has raised concerns about safe and effective forms of prevention. For decades, parents have used the insect repellent DEET(N,N-diethyl-metatoluamide), but questions remain regarding adverse effects,
468

including seizures, particularly when usedin children.
Two large case series suggested thatthe risk of DEET is low. The first collected
poison control center reports during the1980s. The report concluded that DEET
exposure rarely led to adverse effects andthat the route of administration (ie, ingestion) was more closely linked to toxicity
than age or gender.1 There were 5 major
adverse reactions reported from 9086
exposures to DEET (0.05%); these included hypotension, hypotonic reaction, andsyncope, and 1 death (a suicide ingestion).
The second series, also collected frompoison control centers, included roughly
21,000 reports of DEET exposures during
the 1990s. The authors concluded that therisk of toxicity was low and that there wasno clear dose-dependent relationshipbetween exposure and extent of severity ofneurologic manifestations.2 This reportfound a rate of major adverse reactions(0.1%) from DEET that was similar to thefirst case series. The major reactions
reported included hypotension, seizures,respiratory distress, and 2 deaths (0.01%).
When limiting the data to infants and children only, there were 10 major events
among 17,252 reported exposures(0.06%), and no deaths. Although infants
and children accounted for 83.1% of allreported exposures, the majority of theserious outcomes (including the deaths)
occurred in adults. About half of all those
exposed reportedly had no ill effects, theVOL 54, NO 5 / MAY 2005 THE JOURNAL OF FAMILY PRACTICEother half had minor effects (transienteffects that resolved without treatment).
Only 4% experienced moderate effects(non–life threatening problem, but onethat would likely require treatment). There
were no data presented on the overall sizeof the exposed population, eg, users of
DEET in the US.
Two recent narrative reviews also
concluded that DEET toxicity is rare inchildren. The first review found that DEET
posed essentially no risk in children.3 The
second review was sponsored by SC
Johnson and Company, the makers ofOFF! brand insect repellent. It assessed
animal studies, epidemiologic data, andcase reports, and supported the safety of
DEET in children.4
A theoretical risk is that DEET toxicity could be enhanced by coapplication
with other agents. Some studies haveuncovered dangerous interactions withmilitary and industrial chemicals, but such
exposures are unlikely in most children.
The most practical concern regards sunscreen. One study reported that use of sunscreen increased the penetration of DEET.5
However, since the poison control centerstudies indicated that toxicity did notoccur in a dose-dependent manner; theclinical significance of increased penetration is not clear.1,2
Increasing the concentration of DEET
does not improve protection but does provide longer duration. Concentrations of
6.65% protect for about 2 hours while
23.8% DEET can last about 5 hours.6 By
understanding this relationship, parents
can apply lowest concentration necessary
to provide the protection needed.
Recommendations from others
The American Academy of Pediatrics
recommends avoiding DEET in children
under 2 months of age. For all otherchildren, it advises using DEET with a concentration between 10% and 30%.7
REFERENCES

1. Veltri JC, Osimitz TG, Bradford DC, Page BC.
Retrospective analysis of calls to poison control cen-2.

3.

4.

5.

6.

7.

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Is DEET safe for children?

ters resulting from exposure to the insect repellent
N,N-diethyl-m-toluamide (DEET) from 1985–1989.
J Toxicol Clin Toxicol 1994; 32:1–16.
Bell JW, Veltri JC, Page BC. Human exposures to N,Ndiethyl-m-toluamide insect repellents reported to theAmerican Association of Poison Control Centers
1993–1997. Int J Toxicol 2002; 21:341–352.
Koren G, Matsui D, Bailey B. DEET-based insect repellents: safety implications for children and pregnant
and lactating women. CMAJ 2003; 169:209–212.
Erratum in: CMAJ 2003;169:283.
Osimitz TG, Murphy JV. Neurological effects associated with use of the insect repellent N,N-diethyl-m-toluamide (DEET). J Toxicol Clin Toxicol 1997; 35:443–445.
Ross EA, Savage KA, Utley LJ, Tebbett IR. Insect repellent interactions: sunscreens enhance DEET (N,Ndiethyl-m-toluamide) absorption. Drug Metab Dispos
2004; 32:783–785.
Fradin MS, Day JF. Comparative efficacy of insect
repellents against mosquito bites. N Engl J Med 2002;
347:13–18.
American Academy of Pediatrics. West Nile virus information. Available at: www.aap.org/family/wnvjun03.htm. Accessed on April 8, 2005.

What areClinical Inquiries?
Clinical Inquiries answer recent questions fromthe practices of family physicians. Practicing family
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FPIN is national, not-for-profit consortium of family
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❚ FPIN librarians then conduct systematic andstandardized literature searches of best evidence
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FAST TRACKDEET at 10%–30%
concentration
is safe for children
older than 2months; increased
concentration
prolongs action
but does not
improve protection❚ Each Clinical Inquiry is reviewed by 4 or more peers

or editors before publication in JFP.
❚ FPIN medical librarians are accountable for thethoroughness of the literature search, for recording
the databases searched, search hedges used andthe search terms. The details of each search isavailable to any interested reader(contact managingeditor@fpin.org).
❚ Finally, a practicing family physician or otherclinician writes an accompanying commentary toprovide a clinical perspective.
C O N T I N U E Dw w w. j f p o n l i n e . c o m

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