Bug off! Severe toxicity following inhalational exposure to N, N-diethyl-meta-toluamide (DEET).

N, N-diethyl-meta-toluamide (DEET) is an insect repellent currently used by millions of people since 1956. DEET has an excellent safety profile and has remarkable protection against mosquitoes, ticks and various other arthropods. Toxicity is unusual, and is generally associated with incorrect, or overuse of the product. We report a patient with severe toxicity following inhalational exposure to a "bug bomb". containing 98% DEET.

Analysis of diethyltoluamide (DEET) following intentional oral ingestion of Muscol.

N,N-Diethyl-m-toluamide (DEET) is an effective component of several insect repellent products. A 19-year-old woman was admitted to the emergency department following ingestion of 15-25 mL 95% diethyltoluamide (Muscol). Serum and urine toxicology screening tests were negative except for detection of DEET. DEET was qualitatively identified and quantitated by gas chromatography-mass spectrometry. Concentrations of DEET based on selected ion monitoring (ion at m/z 119) were 63.0, 17.2, 1.9, and less than 0.2 mg/L in serum specimens collected at 2, 5, 24, and 48 h following ingestion, respectively. Serial monitoring of DEET concentrations and the cardiac abnormalities observed in this case following oral ingestion were not reported previously.

Toxic encephalopathy associated with use of DEET insect repellents: a case analysis of its toxicity in children.

(1) Respiratory distress and seizures developed in an 18-month-old boy following brief exposure to low-strength (17.6%) N,N-diethyl-m-toluamide (DEET). A review of the literature revealed 17 reports of DEET-induced encephalopathy in children. The objective of this study was to test the hypothesis that the potential toxicity of DEET is high and that available repellents containing DEET, irrespective of their strength, are not safe when applied to children's skin. (2) Although this is a case report, we used the features of published reports of DEET-induced encephalopathy in children to support the diagnosis, since the evidence that the child's illness was caused by DEET was circumstantial. In the following case analysis, clinical reports of children < 16 years old have been reviewed and analyzed in an effort to relate direct DEET toxicity to various clinical, demographic, and toxic compound exposure factors (Fisher's exacttest and logistic regression analysis). (3) DEET-induced encephalopathy in children (56% girls) followed not only ingestion or repeated and extensive application of repellents, but also a brief exposure to DEET (45%). Of those who reported a dermal exposure, 33% reported an exposure to a product containing DEET < 20%. Seizures, the most prominent symptom (72%), were significantly more frequent when DEET solutions were applied to the skin (P<0.01). Mortality (16.6%) did not correlate significantly with the concentration of the DEET liquid used, duration of skin exposure, pattern of use, age, or sex. (4) Data of this case analysis suggest that repellents containing DEET are not safe when applied to children's skin and should be avoided in children. Additionally, since the potential toxicity of DEET is high, less toxic preparations should be probably substituted for DEET-containing repellents, whenever possible.

Fenvalerate/N,N-diethyl-m-toluamide (Deet) toxicosis in two cats.

Toxicosis attributable to fenvalerate and N,N-diethyl-m-toluamide (Deet) exposure was suspected in 2 cats. Clinical signs of toxicosis developed within 4 to 6 hours of dermal application of the pesticide. Clinical signs of toxicosis seen in both cats included hypersalivation, ataxia, and depression. In addition, seizures were seen in 1 cat. Both cats died. Analysis of skin, kidney/urine, liver, and brain tissues confirmed the presence of fenvalerate and Deet. The pyrethroid fenvalerate and the insect repellent Deet are used for the control of fleas and ticks on cats. Suspected fenvalerate/Deet toxicosis in cats is associated with tremors, hypersalivation, ataxia, vomiting, depression, and seizures.

Diethyltoluamide (DEET) insect repellent toxicosis.

Poisonings resulting from DEET are rarely encountered in companion animals. In human patients, DEET toxicosis has been associated with the development of a toxic encephalopathy characterized by tremors, seizures, behavioral changes, and abnormal movements. Generally, DEET toxicosis in companion animals is of short duration and is characterized by vomiting, tremors, ataxia, and excitation. Treatment for DEET toxicosis includes symptomatic therapy and decontamination.

Chemical sensitivity in symptomatic Cambodia veterans.

Following their participation in a United Nations peacekeeping operation in Cambodia (1992-1993), Dutch veterans complained of symptoms similar to those reported by Gulf War veterans. The authors conducted a matched case-control study to evaluate 76 symptomatic and 32 matched asymptomatic Cambodia veterans on the basis of data collected by postal questionnaire. The number of symptomatic veterans who reported having used insect repellants that contained N,N,-diethyl-meta-toluamide (DEET) during the mission in Cambodia was significantly higher, compared with asymptomatic veterans. The percentage of veterans who reported feeling ill following brief exposures to chemicals such as paint or pesticides was equal in both groups, but the percentage was low compared with the results of other studies of Multiple Chemical Sensitivity Syndrome. The current study was limited by self-report and time delay (potential recall bias) between deployment to Cambodia and the time of survey. Nevertheless, the study results did not support the hypothesis that symptoms in the total group of Cambodia veterans could be related to Multiple Chemical Sensitivity Syndrome.

A lethal case of DEET toxicity due to intentional ingestion.

A 37-year-old male with prior medical history of profound developmental delay experienced seizure and cardiac arrest following ingestion of 6 ounces of a 40% N, N-diethyl-meta-toluamide (DEET) containing solution. The patient was unresponsive, acidemic, tachycardic and hypotensive on presentation. Over three hospital days, the patient's vitals recovered to baseline but he remained unresponsive and areflexic with fixed and dilated pupils. Non-contrast brain magnetic resonance imaging showed cerebral edema, transtentorial and tonsillar herniations. A rapid, simple and sensitive high-performance liquid chromatography (HPLC) method was utilized for the analysis of postmortem plasma blood and urine samples of a lethal case of DEET intentional ingestion. The method combined the use of C18 SepPak cartridges for solid phase extraction and reversed-phase HPLC. One urine and five blood samples from this patient were analyzed for DEET concentration. Mixtures of serum/urine postcentrifuge were eluted and reduced to 1 mL using a solvent evaporator. Blood in ethylenediaminetetraacetic acid (EDTA), whole blood, serum, blood with heparin and urine DEET concentrations were 9.84, 9.21, 10.18, 8.66dl and 0.642 mg/dL, respectively. All samples were collected <1 h postingestion. Although seizures and cardiac toxicity have been described in other case reports, this case is atypical due to the exceptional dose ingested and the timing of the fluid test samples being drawn so soon following exposure. Although a widely used and extremely safe insect repellent, DEET can be highly toxic in large but easily obtainable doses.

Severe acute illness in a toddler exposed to multiple agricultural pesticides and an insect repellent.

Acute severe pesticide-related illness among farm worker children is rarely reported. The authors report a toddler with acute onset of apnea, cyanosis, somnolence, hypotonia, tachycardia, and miosis who required hospitalization. Health care providers suspected pesticide poisoning, but were unable to determine the causal agent. Investigation by a public health program documented four pesticide exposures that occurred within one-half hour of acute illness. This case illustrates the importance of a thorough environmental/occupational exposure history and obtaining biological samples. It also documents the need to strengthen the Worker Protection Standard for agricultural workers and the importance of reporting and investigating pesticide-related illness.

Mosquito repellents and superwarfarin rodenticides--are they really toxic in children?

PURPOSE OF REVIEW: In many United States households, there are many substances used to control the exposure of our children to mosquitoes, mice and rats. This review provides information on common mosquito repellents and rodenticides used in households and discusses their toxicity, in order to help pediatricians better advise their patients of their proper use. RECENT FINDINGS: A recent study has demonstrated that many continue to have practices of applying DEET (N,N-diethyl-3-methylbenzamide) based repellents that may lead to undesirable effects. Picaridin and oil of lemon eucalyptus are two products that have recently been shown to have an efficacy similar to that of DEET-based repellents. Studies within the last five years show that most unintentional superwarfarin ingestions can be managed at home with close outpatient follow-up. There does not appear to be a benefit of prophylactic vitamin K or gastrointestinal decontamination in patients with relatively small ingestions of superwarfarins. SUMMARY: With education and correct usage, mosquito repellents and the superwarfarin rodenticides can help protect children from significant vector-borne diseases. Not all exposures lead to significant morbidity or mortality. With recognition of the current literature, most of these exposures can be managed safely at home or as an outpatient, ultimately saving healthcare costs.

Human Exposures to N,N-diethyl-m-toluamide insect repellents reported to the American Association of Poison Control Centers 1993-1997.

This study analyzed 20,764 exposures involving insect repellants containing N,N-diethyl-m-toluamide (DEET) that were reported to poison control centers from 1993 to 1997. Nearly 70% of the cases reported no symptoms related to the exposure. The occurrence of symptoms was related to the route of exposure, with the highest rates associated with ocular exposures, followed by inhalation, multiple exposure routes, dermal, and ingestion. Two deaths were reported, one in a 26-year-old male and one in a 34-year-old female, both following a dermal exposure. Twenty-six subjects experienced major effects. The greatest number of reported exposures involved infants and children, but this group experienced lower rates of adverse effects than teens or adults. There was no clear relationship between DEET concentration and presence or severity of clinical effects. For the cases reported to poison control centers and included in this analysis, the risk of serious medical effects for labeled use of insect repellants containing N,N-diethyl-m-toluamide appears to be low.

Retrospective analysis of calls to poison control centers resulting from exposure to the insect repellent N,N-diethyl-m-toluamide (DEET) from 1985-1989.

This study analyzed 9,086 human exposures involving N,N-diethyl-m-toluamide--containing insect repellents that were reported to Poison Control Centers from 1985-1989. Nearly two-thirds of those exposed had no adverse effects or only experienced minor symptoms that resolved rapidly. Symptoms were more likely to occur after ocular or inhalation exposures and least likely to occur if the product was ingested. The only reported death occurred in a patient who suicidally ingested 8 oz of an insect repellent containing N,N-diethyl-m-toluamide. Five patients may have experienced a serious or potentially life-threatening effect but the poison center record did not provide unequivocal substantiation of the effect or clearly establish N,N-diethyl-m-toluamide as the causative agent. From the analysis of those patients calling Poison Control Centers, it appears the risk of serious medical effects with the labeled use of N,N-diethyl-m-toluamide-containing insect repellents is low in comparison with its reported annual use by about 30% of Americans. For patients contacting Poison Control Centers, the occurrence of adverse effects appears to be related to the route of exposure rather than age or gender of the patient or the concentration of N,N-diethyl-m-toluamide in the product.

Acute manic psychosis following the dermal application of N,N-diethyl-m-toluamide (DEET) in an adult.

Extensive animal testing and 30 years of human experience have established the general safety of DEET when applied episodically to skin or bedclothes. Local and systemic toxic and allergic reactions to DEET have been observed in man. Three weeks prior to admission, for the purpose of self-medication, a 30 year old man began daily applications of the insect repellant, DEET followed by a 1-2 hour period in a light-bulb heated box. Sedation and incoherence were noted for short periods following each application session. Aggressiveness and psychotic ideation led to hospital admission where he displayed psychomotor hyperactivity, rapid and pressured speech, tangentiality, flight of ideas, and grandiose delusions. Treatment was begun with haloperidol. Clinical improvement was complete within 6 days, atypical for classic endogenous mania. Drug and metabolites were identified in the urine more than 2 weeks after the last drug application.

Severe neurotoxic reaction associated with oral ingestion of low-dose diethyltoluamide-containing insect repellent in a child.

N,N-Diethyl-m-toluamide (DEET) is the major component of almost all tick repellent products. Reports of severe adverse reactions following voluntary ingestion are rare and primarily involve adults. This report describes a case of a toxic reaction after ingestion of low doses (80 mg/kg) of DEET in a child. The signs and symptoms were coma and seizures within 2 hours of ingestion. The patient recovered without sequelae. It is concluded that even scant doses of DEET may provoke severe encephalopathy in small children, and caution should be used when leaving this chemical unattended.

Insect repellent (N,N-diethyl-m-toluamide) cardiovascular toxicity in an adult.

OBJECTIVE: To describe a case of N,N-diethyl-m-toluamide (DEET)-induced cardiovascular toxicity in an adult and reviews other cases that have been reported in the published literature. Human and animal data available on DEET pharmacokinetics are reviewed and factors that predispose an individual to DEET toxicity are identified. DATA SOURCES: Case report information was obtained through personal contact with the patient during hospitalization and by telephone, and also from the patient's medical records. Computerized literature searches were conducted with the following systems to obtain medical literature on DEET toxicity: TOXLINE, International Pharmaceutical Abstracts, and MEDLINE. Index Medicus was searched manually. STUDY SELECTION: All reported cases of DEET toxicity in children and adults were reviewed. DATA EXTRACTION: Case reports were evaluated for the quantity of the DEET exposure (topical or oral), the clinical manifestations of the exposure, and the outcome of the exposure. DATA SYNTHESIS: This case is similar in some aspects to those already in the literature; however, very few cases of DEET toxicity in adults have been reported. Cardiovascular toxicity in humans related to DEET application has not been previously reported in the published medical literature. DEET exposure (topical or oral) results in a highly variable clinical course. Whether the outcome is death or recovery without sequelae is difficult to predict. CONCLUSIONS: Adults, as well as children, are at risk for toxicity from insect repellents. The use of highly concentrated DEET-containing insect repellents should be avoided to reduce the risk of toxicity in both children and adults. The consequences of DEET toxicity are variable and unpredictable.

Self-reported exposure to neurotoxic chemical combinations in the Gulf War. A cross-sectional epidemiologic study.

OBJECTIVE: To identify risk factors of factor analysis-derived Gulf War-related syndromes. DESIGN: A cross-sectional survey. PARTICIPANTS: A total of 249 Gulf War veterans from the Twenty-fourth Reserve Naval Mobile Construction Battalion. DATA COLLECTION: Participants completed standardized booklets measuring self-reported wartime exposures and present symptoms. MAIN OUTCOME MEASURES: Associations of factor analysis-derived syndromes with risk factors for chemical interactions that inhibit butyrylcholinesterase and neuropathy target esterase. RESULTS: Risk of syndrome 1 ("impaired cognition") was greater in veterans who reported wearing flea collars during the war (5 of 20, 25%) than in those who never wore them (7 of 229, 3%; relative risk [RR], 8.7; 95% confidence interval [CI], 3.0-24.7; P<.001). Risk of syndrome 2 ("confusion-ataxia") increased with a scale of advanced adverse effects from pyridostigmine bromide (chi2 for trend, P<.001), was greater among veterans who believed they had been involved in chemical weapons exposure (18 of 108, 17%) than in those who did not (3 of 141, 2%; RR, 7.8; 95% CI, 2.3-25.9; P<.001), and was increased in veterans who had been in a sector of far northeastern Saudi Arabia on the fourth day of the air war (6 of 21, 29%) than in those who had not been (15 of 228, 7%; RR, 4.3; 95% CI, 1.9-10.0; P=.004). Effects of perceived chemical weapons exposure and advanced adverse effects from pyridostigmine were synergistic (Rothman S, 5.3; 95% CI, 1.04-26.7). Risk of syndrome 3 ("arthro-myo-neuropathy") increased with an index of frequency and amount of government-issued insect repellent containing 75% DEET (N,N-diethyl-m-toluamide) in ethanol applied during the war (chi2 for trend, P<.001) and with advanced adverse effects from pyridostigmine (chi2 for trend, P<.001). CONCLUSION: Some Gulf War veterans may have delayed, chronic neurotoxic syndromes from wartime exposure to combinations of chemicals that inhibit butyrylcholinesterase and neuropathy target esterase.

Problemática de la coadministración del repelente de insectos DEET y bromuro de piridostigmina en el pretratamiento de las intoxicaciones por agentes neurotóxicos de guerra / Problems form deet insect repellent and pyridostigmine bromide nerve agent pretreatment coexposure

DEET sigue siendo considerado el más eficaz de los repelentes de insectos disponibles, tanto por su espectro de acción como por la duración del efecto. El pretratamiento con bromuro de piridostigmina (BP) es el pretratamiento de las intoxicaciones por agentes neurotóxicos de guerra implantado en la mayoría de las Fuerzas Armadas de las naciones de la OTAN. Las asociación DEET-BP ha sido estudiada como factor causal de las neuropatías que padecen algunos veteranos de la primera Guerra del Golfo Pérsico y si bien a fecha de hoy no se ha demostrado esta relación, distintos estudios in vivo en modelos animales indican un efecto tóxico potenciado al coadministrar ambas sustancias. Por este motivo se recomiendan alternativas al DEET durante el período de pretratamiento con BP, sobre todo las de tipo pasivo, ya que no hay estudios de interacción toxicológica entre el BP y otros repelentes (AU)

DEET is the most effective insect repellent currently available, as a consequence of its broad action spectrum an long lasting effect. Nerve agent pretreatment with pyridostigmine bromide (PB) is the common action in NATO countries DEET-PB association has been studied as an origen of neuropathies affecting some veterans from the first Gulf War. Although no relationship has been established presently, different in vivo studies in animal models show an increased toxic effect when there is a coexposure to both substances. For this reason DEET alternatives are recommended in the meantime of PB pretreatment. Passive measures are specially recommended while there are no studies in toxicological interactions of PB and other coexposures with repellents of insects (AU)