January/February 2012 • Volume 10 • Issue 1 - SKINmed Journal

January/February 2012 Volume 10 • Issue 1
COSMETIC SCIENCE
Howard A. Epstein, PhD, Section Editor
Repelling Insects With Safe and Effective
Alternatives to DEET
In addition to the annoying itch that results from biting
insects, insect-borne diseases, including Lyme disease,
encephalitis, Rocky Mountain spotted fever, and West Nile
virus, are all causes of concern for many individuals who wish to
enjoy the outdoor environment during the warmer months of the
year. The military of various nations experienced the same problems
and have conducted much research in developing repellents
to protect their soldiers. The Indian Army used oils of citronella,
camphor, and paraffin as repellents. These agents were effective
for limited periods and therefore the search for more effective
repellents continued. In 1953, N, N-diethyl-m-toluamide
(DEET) was discovered (Figure 1). As of 2007, it was estimated
that 15 million people in the United Kingdom, 78 million people
in the United States, and 200 million people globally use
DEET each year. 1 Over the years, as cases of insect-borne diseases
continued to be reported in the news, so has the use of
DEET. Reports of adverse reactions associated with DEET have
increased with its use.
HEALTH-RELATED ISSUES AND
CONSUMER CONCERNS
In 2004, the Oregon State University (OSU) Agricultural Experiment
Station issued a press release entitled “OSU Scientist Gives
Safety Tips for Use of DEET Against Mosquitoes & West Nile
Virus.” In the release, Dr Damiel Sudakin, an assistant professor
at OSU’s Department of Environmental and Molecular Toxicology
and toxicologist at the Agricultural Experiment Station was quoted
as expressing concern that hundreds of adverse reactions, most commonly
affecting the skin, are reported each year. The majority of
these adverse reactions occur when DEET is overused or misused. 2
In 2009, Science Daily published a paper entitled “Popular Insect
Repellent DEET Is Neurotoxic.” 3 The contribution referenced a
study that concluded that DEET is not simply a behavior-modifying
chemical, but also inhibits the activity of a key central nervous system
enzyme, acetylcholinesterase, in both insects and mammals. 4
Howard A. Epstein, PhD
In 2004, the Agency for Toxic Substances & Disease Registry issued
a report on the health effects of DEET in humans. The report mentioned
6 cases of DEET ingestion, 3 led to death after ingestion
of 15 mL to 50 mL of 47.5% to 95% DEET filled in bottles. In
2 of these cases, the individuals drank an unspecified amount of
alcohol. In the third case, the individual ingested an unspecified
number of pills with 50 mL of DEET. In yet another case, a woman
ingested 15 mL to 25 mL of 95% DEET and was admitted to a
hospital with right and left atrial enlargement that returned to normal
within 24 hours. This woman survived with no further cardiac
abnormalities. 5 From 1961 to 2002, the Agency reported 8 deaths
related to DEET exposure, 3 resulting from deliberate ingestion,
and 2 following dermal exposure to DEET. The remaining 3 cases
were girls aged 17 months, 5 years, and 6 years. All 3 children were
described as having “heavy, frequent, or nightly applications of
DEET.” The 6-year-old had congenital ornithine carbamoyl transferase
deficiency, which may have contributed to her death. 5 Two
other reported cases involved 2 men, aged 27 and 30 years, who
developed severe psychological effects from exposure to DEET. In
both cases, the men recovered after hospitalization. 5
MILITARY AND GOVERNMENT PERSONNEL:
DERMAL EFFECTS OF DEET EXPOSURE
Unique cutaneous side effects were reported in 15 soldiers who
applied military-issued DEET repellents. One soldier applied a
33% DEET repellent to his skin without washing it off at bedtime.
He developed a vesiculobullous eruption, which cleared after
14 days. Another soldier who went to bed without removing
DEET applied to his skin woke up 8 hours later complaining of
a burning sensation and skin eruptions. A 10-day treatment with
corticosteroids cleared the condition. Other soldiers reported
burning skin and erythema after application of 50% DEET
solution applied just before bedtime. Three soldiers were referred
to treatment by a dermatologist: 2 of the soldiers developed a
permanent scar and 1 required corrective surgery. 5
From EMD Chemicals Inc, Gibbstown, NJ
Address for Correspondence: Howard A. Epstein, PhD, EMD Chemicals Inc, One International Plaza, Suite 300, Philadelphia, PA 19113 •
E-mail: howard.epstein@merckgroup.com
SKINmed. 2012;10:36–39 36
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