DEET Toxicity – rudms.com

DEET Toxicity

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Posted by rudms October 14, 2021

 

8 Attention-grabbing Info of DEET Toxicity

  1. N,N-diethyl-3-methylbenzamide (DEET) is a standard insect repellent; potential toxicity might manifest with:
    • Dermal reactions from topical utility often happen in affiliation with merchandise containing excessive DEET concentrations (better than 50%)
    • Neurotoxicity (eg, lethargy, seizures, poisonous encephalopathy) with important systemic absorption; most instances of great systemic toxicity consequence from ingestion, notably intentional ingestion, and improper dermal use (eg, frequent utility of high-concentration product, particularly in kids)
  2. Most DEET exposures end in minimal to no toxicity and toxicity is usually thought of uncommon; DEET is secure and efficient when used as really helpful in adults, kids older than 2 months, and pregnant and lactating girls
  3. Analysis is essentially medical and based mostly on historical past and bodily examination
  4. Therapy rests on eradicating supply of publicity, decontamination measures, and supportive care; no antidote is accessible for the remedy of toxicity
  5. Admit affected person with progressive or extreme signs for monitoring and supportive care (admission standards usually are not rigorously outlined) in session with poison management middle
  6. Monitor exposures in session with poison management middle or medical toxicologist
  7. Restoration inside 36 hours is anticipated in sufferers surviving systemic manifestations of toxicity, given acceptable supportive care
  8. Prevention is likely one of the most necessary features of care; keep away from use of DEET in kids youthful than 2 months, restrict focus of DEET-containing product to 30% or much less in infants and youngsters, and keep away from overapplication and continual utility of DEET-containing merchandise

Pitfalls

  • Attaining a stability in stopping each insect and extreme DEET publicity could also be difficult in areas of excessive tick and mosquito endemicity
    • Counsel caregivers of younger kids and sufferers residing in tick- and mosquito-endemic areas about DEET toxicity prevention measures and alternate measures to forestall publicity to bugs (eg, avoidance of daybreak and nightfall, long-sleeved clothes)
  • DEET (N,N-diethyl-3-methylbenzamide; diethyltoluamide) is a standard insect repellent; potential toxicity might manifest with:
    • Dermal reactions from topical use; reactions often happen in affiliation with merchandise containing excessive DEET concentrations (better than 50%)
    • Neurotoxicity (eg, lethargy, seizures, poisonous encephalopathy) with important systemic absorption; most instances of great systemic toxicity consequence from ingestion, notably intentional ingestion, and improper dermal use (eg, frequent utility of high-concentration product, particularly in kids)
  • Most DEET exposures end in minimal to no toxicity and severe toxicity is taken into account uncommon; DEET is secure and efficient when used as really helpful in adults, kids older than 2 months, and pregnant and lactating girls

Classification

  • Publicity is assessed by the US Division of Well being and Human Companies as both acute (14 days or much less), intermediate (15-364 days), or continual (twelve months or longer)

Scientific Presentation

Historical past

  • Signs often happen inside an hour of poisonous publicity and fluctuate considerably by route of publicity
    • Inhalation
      • Oral irritation, choking, coughing, and dyspnea might develop quickly after publicity
      • Gastrointestinal signs (eg, nausea, vomiting) might develop
    • Dermal
      • Generalized hives inside 10 to half-hour of utility
      • Acute onset of tingling and erythema
      • Extreme hemorrhagic vesiculobullous eruptions
        • Could happen after utility to areas occluded throughout sleep (primarily antecubital fossa and popliteal fossa) and use of merchandise containing excessive DEET focus (better than 50%)
        • Pores and skin necrosis and desquamation could also be related to extreme reactions
      • Exacerbation of current pores and skin situations (eg, psoriasis, atopic dermatitis)
    • Ocular
      • Acute onset of eye irritation and conjunctivitis
    • Oral ingestion
      • Acute onset of epigastric ache, nausea, and vomiting
      • Numbness and tingling of mucous membranes
    • Systemic results because of extreme absorption
      • Gastrointestinal results
        • Stomach ache, nausea, and vomiting
      • Neurologic signs
        • Headache
        • Drowsiness or lethargy
        • Restlessness, irritability, agitation, aggression, and combativeness
        • Seizures
        • Impaired cognitive perform and disorientation
        • Ataxia and slurred speech
        • Tremors and uncontrolled limb motion
        • Muscular cramping, weak point, and rigidity

Bodily examination

  • Dermal publicity findings
    • Urticarial lesions
    • Localized response with erythema and tenderness
    • Hemorrhagic vesiculobullous eruption adopted by pores and skin erosion and desquamation
  • Ocular publicity findings
    • Conjunctival injection with out ulceration
  • Inhalational publicity findings
    • Bronchospasm with wheezing or crackles
  • Indicators of systemic toxicity
    • Cardiovascular results
      • Tachycardia, bradycardia, hypertension, or hypotension
    • Neurologic manifestations
      • Encephalopathic indicators similar to psychological standing modifications, coma, seizures, opisthotonos, flaccid paralysis, and areflexia
      • Indicators in step with peripheral neuropathy (eg, diminished sensation)
      • Indicators of elevated intracranial strain and cerebral edema with herniation might develop with excessive toxicity

Causes

  • Vital DEET toxicity sometimes happens from both:
    • Extreme use or repeated cutaneous publicity to excessive concentrations of DEET-containing product, or
    • Intentional ingestion
  • DEET formulations and normal info
    • DEET is efficient in opposition to mosquitoes, chiggers, biting flies, fleas, and ticks; mechanism of motion is essentially unknown
    • Obtainable industrial product formulations embrace aerosol and nonaerosol sprays, lotion, cream, gel, foam, sticks, and wipes
    • Most commercially accessible merchandise include concentrations of lower than 30% to 40% DEET (vary 4%-100% by weight)
    • Insect repellent results plateau at a focus of about 50% DEET after topical utility
    • Larger DEET concentrations have longer lasting results than merchandise containing decrease concentrations; subsequently, merchandise containing larger DEET concentrations require much less frequent reapplication
      • Efficacy instances are approximate: 10% DEET lasts about 2 hours, 30% lasts about 5 hours, and 100% lasts about 10 hours
  • Routes of publicity might embrace:
    • Dermal toxicity
      • Publicity leading to toxicity might happen after a number of functions to the pores and skin, notably with preparation with excessive focus of DEET
    • Oral ingestion
      • Publicity leading to toxicity could also be unintentional (eg, exploratory ingestion in younger kids) or intentional (eg, suicide try in grownup)
    • Inhalation publicity
      • Publicity leading to toxicity might happen when aerosol formulations are used, notably in confined areas and when sprayed close to the face
  • Pharmacokinetics
    • Absorption
      • Environment friendly absorption happens throughout pores and skin and gastrointestinal tract
      • Dermal publicity: peak plasma focus is reached 1 hour after utility
    • Metabolism
      • Happens by way of oxidative enzymes within the liver
  • Poisonous dose
    • Particular poisonous dose is just not definitively recognized
    • Ingestion of DEET might end in speedy and extreme toxicity

Threat elements and/or associations

Age
  • Infants and youngsters could also be at elevated danger for DEET toxicity owing to a better dermal absorption secondary to elevated floor space to physique weight ratio
Different danger elements/associations
  • Threat elements for extreme toxicity embrace:
    • Improper use (overly frequent utility, continual use)
    • Ingestion
    • Use of excessive focus, notably in kids
  • Absorption of DEET from the pores and skin could also be enhanced by different topical compounds, similar to sunscreen, ethanol, and sure retinoids
  • Very restricted information recommend that impaired capacity to metabolize ammonia (eg, inborn errors of metabolism involving the urea cycle) might enhance the chance for DEET toxicity

Diagnostic Procedures

Major diagnostic instruments

  • Analysis is essentially medical and based mostly on historical past and bodily examination
    • Contemplate in sufferers with a historical past of DEET-containing product use and constant cutaneous or neurologic manifestations
    • Contemplate lumbar puncture and neuroimaging to help in differential prognosis for sufferers with severe neurologic manifestations and unclear prognosis
    • Plasma concentrations of DEET can affirm publicity however usually are not available or helpful to information remedy
  • No laboratory testing is indicated for many exposures
    • Contemplate the next routine laboratory analyses for sufferers with proof of important systemic toxicity (eg, central nervous system manifestations, cardiovascular findings):
      • Serum glucose degree, electrolyte ranges, and renal perform
      • Blood gasoline and lactic acid degree
      • CBC, prothrombin time, and partial thromboplastin time
      • Hepatic perform and blood ammonia degree
  • Contemplate routine research indicated for sufferers with intentional ingestion
    • Acetaminophen focus
    • Urine being pregnant check in girls of child-bearing age
    • ECG to evaluate for conduction abnormalities requiring intervention

Laboratory

  • Cerebrospinal fluid evaluation
    • Receive neuroimaging earlier than cerebrospinal fluid evaluation in sufferers with indicators of elevated intracranial strain
    • Contemplate to help in exclusion of infectious or inflammatory central nervous system course of in sufferers with neurologic manifestations
    • Lymphocytic pleocytosis with regular glucose ranges and regular or elevated protein ranges could also be famous in sufferers with DEET toxicity

Imaging

  • Neuroimaging
    • Contemplate to help differential prognosis in sufferers with important neurologic manifestations

Differential Analysis

Commonest

  • Acute encephalitis
    • Irritation of the mind parenchyma ensuing from infectious or autoimmune causes
    • Characterised by signs of encephalopathy (eg, alterations in consciousness, character modifications), which can be much like these seen in DEET toxicity
    • In contrast to DEET toxicity, acute encephalitis can be characterised by fever, cerebrospinal fluid pleocytosis, or attribute modifications on MRI or electroencephalography
    • Differentiate by establishing proof of cerebrospinal fluid irritation by lumbar puncture
    • Analysis is predicated on medical presentation, neuroimaging, lumbar puncture, and subsequent laboratory analyses to assist determine the trigger
  • Organophosphate or carbamate poisoning
    • Acetylcholinesterase-inhibiting pesticides can have all kinds of results relying on the agent, route, and period of publicity
    • Central nervous system results (eg, headache, dizziness, restlessness, ataxia, seizures) and a few nicotinic results (eg, paralysis, weak point, cramping) might resemble these of DEET toxicity
    • In contrast to DEET toxicity, acetylcholinesterase-inhibitor poisoning is often characterised by concomitant muscarinic results (eg, pupil constriction, sweating, lacrimation, salivation, wheezing, diarrhea, bradycardia, incontinence) and cardiac conduction interval prolongation (eg, atrioventricular block, QT prolongation)
    • Analysis is predicated on medical presentation; presence of muscarinic results raises robust suspicion for organophosphate poisoning
  • Pyrethrin and pyrethroid toxicity
    • Pyrethrins and pyrethroids are pesticides included in lots of industrial merchandise (eg, pet merchandise, merchandise for utility on clothes)
    • Poisonous publicity is uncommon and systemic toxicity often solely happens after ingestion owing to very gradual dermal absorption; nevertheless, pores and skin publicity can lead to native irritation and paresthesia
    • Could current equally to DEET toxicity with historical past of insect management product use, vomiting, ataxia, altered psychological standing, seizures, and coma
    • Sufferers with pyrethroid toxicity sometimes manifest with indicators which will assist distinguish from DEET toxicity, similar to salivation, hyperexcitability, and sympathomimetic hyperactivity
    • Period of toxicity from poisoning is considerably longer than period sometimes related to DEET poisoning
    • Analysis is predicated on medical presentation and remedy mirrors that of DEET toxicity (eg, symptomatic care)

Therapy Targets

  • Take away supply of publicity and provoke decontamination measures
  • Present symptomatic and supportive care

Disposition

Admission standards

Admit affected person with progressive or extreme signs for monitoring and supportive care (admission standards usually are not rigorously outlined) in session with poison management middle and medical toxicologist

Preserve a low threshold for admission of sufferers at excessive danger for potential toxicity similar to these with:

  • Underlying metabolic dysfunction, hepatic illness, or extreme comorbidity
  • Publicity to excessively excessive quantities and concentrations of DEET
  • Vital enteral ingestion
Standards for ICU admission
  • Admit sufferers with severe manifestations (eg, hypotension, coma, seizures) to the ICU for supportive care

Suggestions for specialist referral

  • Seek the advice of native poison management middle and medical toxicologist for sufferers with any publicity to help with remedy suggestions and monitoring parameters

Therapy Choices

Take away supply of publicity and provoke decontamination measures

  • For sufferers with dermal publicity
    • Take away contaminated clothes, irrigate pores and skin with copious quantities of water, and wash pores and skin with cleaning soap and water
    • Preserve care to scrub behind ears, below nails, and in pores and skin folds
  • For sufferers with ocular publicity
    • Take away contact lenses when current
    • Irrigate eyes with copious quantities of sterile water or saline
    • Carry out ocular fluorescein analysis as is indicated after any chemical publicity
    • Pursue additional evaluation in session with ophthalmologist if irritation persists regardless of extended irrigation
  • For sufferers with oral publicity
    • Don’t use ipecac to induce emesis
    • The effectiveness of activated charcoal in DEET ingestions is unsure; cautious use of a number of dose activated charcoal will be thought of in sufferers with important ingestion publicity
    • Could take into account charcoal in sufferers with intentional ingestion lower than 2 hours earlier than presentation involving a number of substances, given absence of contraindications

No particular antidote exists for DEET toxicity

First line remedy is symptomatic remedy and supportive care

  • Handle seizures in commonplace style as indicated for toxin-induced seizures
    • Benzodiazepines are first line remedy
    • Deal with refractory seizures with barbiturates (eg, phenobarbital)
  • Handle hypotension in commonplace style
  • Administration for dermal toxicity
    • Topical steroids and oral antihistamines could also be required for important pores and skin reactions after decontamination course of
  • Administration for poisonous encephalopathy
    • Mirrors commonplace remedy for noninfectious encephalopathy with supportive care and commonplace administration for elevated intracranial strain when indicated

Nondrug and supportive care

  • Take away supply of publicity
  • Provoke decontamination measures (dermal, ocular, and gastric)
  • Intentional ingestions require psychiatric analysis earlier than contemplating ultimate disposition

Monitoring

  • Monitor exposures in session with poison management middle or medical toxicologist

Problems

  • Demise
    • Demise from DEET toxicity might happen after extreme dermal and oral exposures
    • Reason behind dying is often secondary to cerebral edema with herniation
    • Circumstances leading to dying contain both intentional ingestion or repeated extreme dermal use (together with a baby who had underlying metabolic illness)
  • Poisonous encephalopathy and hepatitis
    • Has been reported in a baby with inborn error of ammonia metabolism

Prognosis

  • Ocular publicity
    • Ocular irritation with out important long-term opposed results
  • Dermal reactions
    • Urticaria sometimes resolve spontaneously
    • Minor localized reactions and pores and skin irritation often resolve with native care
    • Hemorrhagic vesiculobullous eruptions leading to pores and skin necrosis might heal with scarring
  • Systemic toxicity
    • Restoration inside 1 to 2 days is anticipated in sufferers surviving systemic manifestations of toxicity given acceptable supportive care
    • Sufferers with acute poisonous encephalopathy after short-term publicity usually get better pretty quickly with out important sequelae

Prevention

  • Keep away from use of DEET in infants youthful than 2 months
  • Keep away from use of greater than 30% DEET for infants and youngsters
  • The species of Aedes mosquitos that carry dengue fever, Zika virus, yellow fever, and another illnesses are most lively in the course of the day, so mixture merchandise of sunscreen and DEET could also be used judiciously in these settings
    • Nevertheless, sunscreen utilized with DEET ends in elevated systemic absorption of DEET and should diminish the impact of sunscreen merchandise
  • Keep away from use of DEET with topical retinoids
    • Concomitant use of sure topical retinoids (eg, bexarotene, alitretinoin) and DEET might potentiate DEET toxicity
  • Keep away from extreme publicity to DEET-containing merchandise
    • Don’t reapply extra incessantly than really helpful reapplication time
    • Use a product with acceptable DEET focus geared towards anticipated outside publicity time; use the bottom focus of DEET that’s efficient
      • 10% DEET offers safety for about 2 hours
      • 30% DEET offers safety for about 5 hours
    • Restrict utility to uncovered areas of pores and skin and apply sparingly; keep away from use below clothes
    • Keep away from utility to areas with cuts, wounds, or irritated pores and skin
    • Wash off merchandise with cleaning soap and water after returning indoors
    • Wash clothes handled with DEET earlier than subsequent put on
  • Keep away from publicity to mucous membranes, inhalation publicity, and potential for unintentional ingestion
    • Keep away from direct utility to mucous membranes similar to mouth and eyes
    • Don’t apply on to palms in younger kids owing to danger of inadvertent oral or ocular publicity
    • Use aerosols and sprays in open space versus confined areas
    • Keep away from direct aerosolization to facial space; somewhat, spray palms first then apply
    • Hold merchandise containing DEET in authentic marked container
  • Discontinue DEET-containing product instantly if signs similar to rash, headache, or behavioral modifications happen
  • Counsel about alternate strategies to keep away from mosquito and arthropod publicity, together with the next:
    • Keep away from going exterior throughout instances of excessive mosquito exercise (ie, nightfall and daybreak)
    • Keep away from use of robust fragrances, perfumes, scented soaps, or hairspray
    • Put on pants, a long-sleeved shirt, and socks
    • Put on mild colours somewhat than brilliant colours
    • Keep away from areas with damp or rotting vegetation (together with seaweed on seashores)
    • Take away giant areas of particles that might harbor arthropods (eg, tires, extreme yard vegetation)
    • Use insect nets when vital
    • Use intact screens for doorways and home windows (or air-con)
    • Contemplate supplying water reserves (eg, lakes, ponds) with fish and nonpathogenic bacterial species that devour mosquito larvae
    • Eradicate standing water in any container the place bugs can breed
    • Substitute outside lighting with lights that have a tendency to draw fewer bugs (eg, yellow bug lights)
    • Use permethrin-impregnated clothes
  • Use DEET solely with excessive warning in kids with recognized seizure problems, a number of allergy symptoms, extreme atopic dermatitis, underlying hepatic illness, or metabolic dysfunction

References

Diaz JH: Chemical and plant-based insect repellents: efficacy, security, and toxicity. Wilderness Environ Med. 27(1):153-63, 2016

 

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