Sifa Medical Journal

: 2014  |  Volume : 1  |  Issue : 3  |  Page : 39--41

Haemolytic anemia and mothball toxicity: A case report

Ibrahim Aliyu1, Zainab F Ibrahim2,  
1 Department of Paediatrics, Aminu Kano Teaching Hospital, Kano, Nigeria
2 Department of Nursing, Aminu Kano Teaching Hospital, Kano, Nigeria

Correspondence Address:
Ibrahim Aliyu
Department of Paediatrics, Aminu Kano Teaching Hospital, Kano


The risk of mothball poisoning is more in developing countries, where there is poor consumer protection; often products are poorly labeled and in most of the cases, consumers do not have product details. Naphthalene containing mothball poisoning may present late with anemia; and in malaria prone environment such as ours, there is tendency of miss-diagnosis, if history of exposure is not sort. Therefore, the case of a 2-year-old boy who presented 48-hours after exposure with severe anemia warranting blood transfusion is reported.

How to cite this article:
Aliyu I, Ibrahim ZF. Haemolytic anemia and mothball toxicity: A case report.Sifa Med J 2014;1:39-41

How to cite this URL:
Aliyu I, Ibrahim ZF. Haemolytic anemia and mothball toxicity: A case report. Sifa Med J [serial online] 2014 [cited 2023 Jun 6 ];1:39-41
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Naphthalene and 1, 4 dichlorobenzene are the major ingredients in mothball. However, naphthalene is most used; it is a polycyclic aromatic hydrocarbon whose discovery dates back to 1820s. [1] It is a common household pesticide used in preserving cloths (especially newborn clothing) from cloth moths (Tineola bisselliella and Tinea pellionella); it sublimates and the fume has insecticidal properties; furthermore, it is occasionally added to 'ota-piapia' [2],[3] - a common homemade insecticide in many rural Nigerian homes. Common routes of exposure include inhalational and skin contact; occasionally, unintentional ingestion may occur in children; especially following the current practice where mothballs are designed into various shapes and sizes, which may make them attractive to children who can mistake them for sugar cubes and sweets. Though there have been previous reported cases of mothball-poisoning, [4] the aim of this index case is to draw the attention of clinicians and regulatory agencies to the hazard associated with non-regulated use of this chemical; more so exposure to mothballs is often forgotten when evaluating children for anemia.

 Case Report

A 2-year-old boy who was healthy ingested an unquantified amount of mothballs while playing with his elder brother who was 8 years old. He was used to chewing sugar cubes and he mistook the mothballs for sugar. Attempt at inducing emesis by the parents failed and about 4 hours later, he developed vomiting and diarrhea; he progressively became weak with complaint of passing coke-color urine by the second day with associated prostration.

On the second day, he was severely pale with tinge of jaundice; and was afebrile with moderate dehydration; he was tachycardic with a bounding pulse, but normotensive; he had 1 st and 2 nd heart sound with an ejection systolic murmur; the respiratory, central nervous systems examination were not remarkable.

He had dark urine, which was positive for hemoglobin while urine microscopy was negative for red blood cells suggesting hemoglobinuria. He was anemic with hemoglobin of 5 g/dL, total white blood cell count of 15,000 cells/mm 3 , platelet count of 400,000 cells/mm 3 . Peripheral blood smear showed evidence of hemolysis (the presence of nucleated red blood cells, spherocytosis and fragmented red blood cells). He had normal liver function, renal function tests and glucose-6-phosphate dehydrogenase activity. His malaria parasite test was negative. He was transfused for correction of anemia. His health improved and he was discharged by the 5 th day.


Mothballs are mainly naphthalene or 1,4 dichlorobenzene based. Both have strong odor characteristic of mothballs and sublimate as well. Camphor is often erroneously confused with naphthalene, [4] though they are all hydrocarbons and have insecticidal properties. Camphor has medicinal properties and is no more used as mothballs. While most countries have replaced naphthalene with 1, 4 dichlorobenzene because of its high flammability- in the European Union, mothballs have been banned since 2008 - the situation in most resource limited countries is different, because these products still flood our markets and some of these products are poorly labeled, hence consumers are often not aware of their content.

Mothballs are lipophilic and are readily absorbed through the skin, lungs and gastrointestinal tract; however, children tend to absorb it faster therefore they are most prone to toxicity when compared to adults, [4] furthermore, oiling of the skin facilitates faster skin absorption as may occur in newborns whose clothes are preserved with mothballs. [5],[6]

Naphthalene is metabolized in the liver producing reactive metabolites like 1,2-naphthalene oxide, 1,2-naphthoquinone, 1,4-naphthoquinone, 1,4-naphthalene oxide. The epoxide is unstable and undergoes spontaneous rearrangement to 1-naphthol or 2-naphthol, which is conjugated to either glucuronides or sulfates and excreted in the urine; and 1,2-naphthalene oxide could be further metabolized to 1,2-naphthoquinone, which is a cataractogen. [7]

Both ingredients in mothballs are associated with health concerns; whereas 1,4-dichlorobenzene has been linked with the risk of cancer, naphthalene has been associated with complications of the gastrointestinal tract and in anemia, which was observed in the index case and neurotoxicity in severe exposure. Being in a malarial endemic area, this case could have be mistaken for malarial anemia, if the history of exposure to mothballs was not obtained, which was the case in the report of Nte et al. [4] Acute exposure to naphthalene may result in hemolytic anemia, especially in individuals who are glucose-6-phosphate dehydrogenase deficient; [8] though our patient had normal enzyme activity. In acute phase of hemolysis, individuals with less severe enzyme deficiency may have normal enzyme activity due to increased release of young red blood cells with normal enzyme activity. However, intravascular hemolysis results in hemoglobinemia, hemoglobinuria, which was seen in the index case, and in severe cases methhemoglobinemia, acute renal failure may occur as was reported by Nte et al., [4] and Annamalai et al. [9]

Diagnosis of naphthalene poisoning is made from the history of exposure, its characteristic smell and the presence of clinical evidence of hemolytic anemia. Our patient presented 2 days after the incident, which was comparable to the 3-4 days as observed in: Nte et al., [4] Lim et al., [8] and Annamalai et al.; [9] which means the hemolysis can be slowly progressive and even delayed as was reported by Lim et al., [8] hence there is tendency to overlook the relationship with exposure. The index case had blood transfusion; though sodium bicarbonate, steroids, methylene blue [8] were not given, he made remarkable improvement and he was discharged on the 5 th day.

In cases of suspected toxicity, some simple bedside test may come handy in distinguishing the various forms of mothball; naphthalene mothballs float in saturated salt solution and sink in water; paradichlorobenzene mothballs float in both water and saturated salt solution; while camphor mothball float on water only. [8] Furthermore, paradichlorobenzene mothball is radiopaque whereas naphthalene is not. [10]


Naphthalene poisoning may present late and history of exposure to mothball should be sort in all patients presenting with anemia; otherwise, there is risk of over-diagnosing malarial anemia in our setting; and identifying these as risk children is important in order to forestall future occurrence.


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