Medical Complications Due to Mothball Abuse

Eric Weintraub, MD, Devang Gandhi, MD, Charles Robinson, MD, Department of Psychiatry, University of Maryland Medical System, Baltimore.

South Med J. 2000;93(4) 

In This Article


Mothballs are made of naphthalene or paradichlorobenzene, and toilet deodorizers predominantly consist of paradichlorobenzene.[6] Differentiation between the two types of mothballs is difficult because they have similar odors and are both white, crystalline solids at room temperature.[7] Our patient was unable to identify which brands of mothballs she abused; therefore, it is likely that she was exposed to both types. The toxic effects of these two substances are different. Naphthalene has been reported to cause headaches, restlessness, lethargy, vomiting, anorexia, hemolysis, methemoglobinemia, hyperkalemia, fever, anemia, acute renal failure, seizures, and coma.[6,8] Case reports have described toxicity due to acute poisoning in children and occupational exposure in adults. While naphthalene is a component of other commonly abused solvents (model and plastic cement), there have been only four reports[9,10,11] in the English language of naphthalene being abused in isolation. These reports were of a 10-year-old American Indian boy who inhaled naphthalene mothballs for 8 hours nightly for 2 months and died of liver failure after progressive portal hypertension developed; a 26-year-old woman who "sucked on moth balls" during the last trimester of her pregnancy and developed anemia; a 19-year-old woman who smelled, chewed, and sucked mothballs during pregnancy and became anemic; and a 15-year-old boy who sucked mothballs, had mid-epigastric pain and vomiting, and subsequently received a diagnosis of anemia.

Paradichlorobenzene is less acutely toxic than naphthalene, but long-term exposure has been linked to kidney and liver disease.[6,12] As with naphthalene, toxicity has almost always been reported as a result of accidental or occupational exposure. However, there are two reported cases[13,14] in the English language of paradichlorobenzene abuse. In one case, a 19-year-old black woman ingested four to five paradichlorobenzene moth pellets per day for 2 years and had sluggishness and tremulousness when she stopped. In the other case, a 21-year-old woman ingested two paradichlorobenzene toilet air freshener blocks a week while pregnant; anemia developed that did not respond to iron therapy.

Inhalants such as n-hexane and methyl butyl ketone, which have general chemical properties similar to those of paradichlorobenzene and naphthalene, have been reported to cause peripheral neuropathy.[15] However, there is only one report of naphthalene[16] (and only in combination with several other compounds) causing peripheral neuropathy. No cases of paradichlorobenzene-induced peripheral neuropathy have been reported. Our patient had other risk factors that cause peripheral neuropathy, including diabetes and chronic renal failure. Nevertheless, the clinical progression of this case is consistent with a toxic etiology, with an acute onset and subsequent significant improvement when the patient was hospitalized and abstinent from mothball inhalation.[17] Similarly, though the patient had several other major risk factors for the development of renal disease, her medical and neurologic physicians concluded that her abuse of naphthalene and paradichlorobenzene, which are known nephrotoxins, was a contributing, causative factor in her chronic renal failure. Clearly, the role of underlying medical conditions in predisposing this patient to renal failure and peripheral neuropathy cannot be ignored; however, the evidence is consistent with mothball abuse being an important precipitating factor in this case.

This case is unusual because mothballs and the two compounds they contain, naphthalene and paradichlorobenzene, have rarely been reported to have been abused. Most reports of toxicity involve either accidental ingestion or pica and are from short-term use. However, our patient's long-term use and inability to stop despite adverse consequences clearly met the criteria for inhalant abuse in the Diagnostic and Statistical Manual of Mental Disorders-4th Edition.[18] The development of peripheral neuropathy as a result of abuse of these two compounds is also rare, though it has been described in cases of abuse of related chemicals. This case illustrates issues common to the abuse of inhalants: common household products not usually identified as recreational drugs can be abused, and directly linking specific medical problems with particular inhalants can be difficult because of confounding variables. Since patients rarely volunteer that they abuse mothballs and other common household products and physicians rarely ask directly about the use of such substances as intoxicants, there is currently no way of determining the actual prevalence of this type of substance abuse and the frequency with which it may contribute to medical problems. Further research into these issues, as well as treatment, is necessary.


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