Download - Accidental mothball ingestion Case presentation Toxicology course 2005 By Dr. CK Chan, UCH
Accidental mothball ingestion
Case presentationToxicology course 2005
By Dr. CK Chan, UCH
History
F/1, good past health. No G6PD deficiency
Found playing with mothballs in wardrobe
Brought to AED ∵ suspected moth ball ingestion
Asymptomatic
Mothball brought by mother
Packing not available
Investigation? Management plan?
AXR taken No radiopaque sub
stance found Taken mothball?
Progress
Patient observed in “O” room for 4 hours.
Remain asymptomatic ?Really taken a mothball Discharged home with advice
Moth ball / moth repellents
Naphthalene Paradichlorobenzene
Historically, camphor ( 樟腦 ) has been used as moth repellents. Due to its toxicity, it is not used as moth repellent any more.
However camphorated oil ( 樟腦油 ) is still widely available as herbal remedy (cough mixture, local analgesic) & essential oil in aromatic therapy
Camphor
Natural contained in bark/leaves of camphor tree
Hydrocarbon (cyclic ketone) Wet oily crystal with pungent aroma. 1 teaspoon of 20% camphorated oil (1g) has
been reported to cause death in infant 1983 FDA ruling: nonprescription camphor
products should not contain >11% camphor
Clinical manifestations Rapid GI absorption with CNS toxicity
∵ highly lipid soluble Route – mainly GI; dermal & mucosal
absorption, inhalation, transplacental transfer have been reported
Hallmark – generalised tonic-clonic convulsion within minutes to 1-2hrs postingestion
Other toxic effects: CNS depression, GI disturbance, psychiatric effects with hallucination / agitation, liver function derrangement (∵metabolized by liver)
Rarely cause death (4 lethal cases in past 15yrs in USA). Cause of death: status epilepticus & respiratory failure.
Management No specific diagnostic test Gastric lavage – not well-studied,
possibly contraindicated ∵ (1) rapid GI absorption; (2) risk of aspiration (hydrocarbon); (3) early onset convulsion
Activated charcoal – indicated, but efficacy never studied
Supportive care Suspected poisoning – medical
clearance after 4-6 hrs observation.
Naphthalene Most common ingredient of mothball in HK
(all mothballs available in supermarket are naphthalene ball)
Hydrocarbon – rapid GI absorption Hallmark – oxidant stress resulting in napht
halene-induced haemolysis & methaemoglobinemia, especially in susceptible persons (e.g.: G6PD deficiency)
Delayed presentation (>2 days)
Oxidant stress α-Naphthol is the liver metabolite of napht
halene which responsible for naphthalene’s haematogic toxicity
Oxidant stress – oxidizing agents that oxidized the ferrous (Fe2+) iron in haemoglobin to ferric (Fe3+) iron, forming the methaemoglobin
Methaemoglobin has no oxygen carrying capacity, and will preciptate in RBC to cause haemolysis.
Why patients with G6PD deficiency are more susceptible to oxidant stress?
Normal RBC is protected from oxidant stress by the glutathione system
In patient with G6PD deficiency, RBC NADPH production reduced, therefore limiting the efficacy of glutathione system
RBC glucose metabolism
Clinical manifestation In practice, naphthalene-induced haemolysis is mo
re common c/w naphthalene-induced methaemoglobinemia
Development of haemolysis / methaemoglobinaemia takes 1-2d become clinically detectable.
Anaemia secondary to haemolysis takes 3-5 days to develop.
Haemolysis: jaundice (unconjugated hyperbilirubinemia), low serum haptoglobin, direct & indirect Coombs test negative, haemoglobinuria, abnormal peripheral blood smear
Methaemoglobinemia: cyanosis, SaO2 85%, Heinz bodies in RBC in peripheral blood smear
Management GI decontamination: only indicated in multiple mo
thballs ingestion or intentional ingestion Syrup of ipeca: possible useful in children, give within 1 hr
postingestion AC 1g/kg WBI should be considered in massive ingestion, or patient
s with haemolysis /methaemoglobinemia + symptoms suggestive of ongoing delayed GI absorption
Managed as outpatient. Follow up 2/7 later to detect symptoms & signs of haemolysis/ methaemoglobinemia.
Treatment: Supportive, rarely need transfusion. Significant methaemolglobinemia should be treated with methylene blue.
Paradichlorobenzene Replaced naphthalene
as the commonest ingredient of cake / hanger type of moth repellant
Relatively safe – toxicity usually limited to GI disturbance
Unintentional ingestion can be managed as outpatients.
Mothball recognition You got a mothball in
hand. Likely naphthalene ??paradichlorobenzen
e Can it be camphor???
The toxic one float! Camphor mothball flo
at in water (specific gravity <1)
Both naphthalene & paradichlorobenzene sink in water (SG>1)
Naphthalene (SG~1.1) is less dense c/w paradichlorobenzene (SG~1.4). Naphthalene will float up in saturated salt water.
Radiopaque mothball is nontoxic Paradichlorobenzene:
densely radiopaque Naphthalene: faintly ra
diopaque Camphor: radiolucent
*make sure the patient has taken a mothball before ordering a AXR!
Differentiation-floating test - X ray
Float in water
Float in sat. salt solution
X - ray
Camphor yes yes Not opaque
Naphthalene no yes Faintly opaque
Paradichlorobenzene
no no Denselyopaque
Survey of moth repellent in supermarket
1. All mothballs are naphthalene balls 2. All cake type moth repellent contai
n paradichlorobenzene 3. Hanger type can be naphthalene / p
aradichlorobenzene / insecticide with potential toxicity!!
Park’n shop白元高級防蟲餅 (Hanger type, $27.5) Paradichlorobenzene白元箂莉太太防蟲掛裝 (Hanger type with aluminium foil, $27.5)
Empenthrin (pyrethroid ester insecticide)o-phenylphenol (?organic solvent)
拜高防蟲掛裝 (Hanger type, $31.9) Transfluthrin (pyrethroid ester insecticide)
絲莎無味防蟲掛裝 (Hanger type, $45.9) EmpenthrinFreside S (insecticide)
象球牌防蟲防潮劑 (Hanger type, $39.9) Paradichlorobenzene象球牌防蟲片 (Hanger type $23.9) Naphthalene
Park’n Moth repellent (Hanger type, $16.9)
Paradichlorobenzene
Park’n moth ball ($7.9) Naphthalene
Welcome Store
雞仔牌高級防蟲餅 (Hanger type, $26.5)
Naphthalene
蘭香水晶腦 (Hanger type, $12.9)
Paradichlorobenzene
No Frills deodorant hanger ($9.8)
Naphthalene
大利牌高級樟腦餅 (cake, $10.9)
Paradichlorobenzene
No Frills moth ball ($4.9)
Naphthalene