Paradichlorobenzene (PDCB) is a lipophilic molecule used in mothballs.  It is considered safer than the common alternative agent, naphthalene, but toxicity can occur due to accidental ingestion or in those who use it as a drug of abuse.  We are reporting a case of mothball toxicity in a young woman.  

A 30 year-old woman with a history of poly-substance use disorder, post-traumatic epilepsy, and hypothyroidism was brought to the emergency room for altered mental status. Her mental status exam was significant for disorientation, psychomotor retardation, and bizarre thought content. Labs at that time were significant for leukocytosis, microcytic anemia, low TSH and free T4, pyuria, and bacteriuria. The patient’s family reported that four months prior to presentation, the patient had facial rash, difficulty balancing, irritability, anger, and weight loss. Her father had found mothballs around the house, and also saw patient chewing what appeared to be mothballs. An MRI was performed and showed bilateral confluent white matter hyperintensity with no focus of restricted diffusion and no abnormal contrast enhancement. This finding was consistent with paradichlorobenzene toxicity from mothball ingestion.  Her mental status improved during her four-month hospitalization, but she did not return to baseline.

In the United States, PDCB is the most common active ingredient in mothballs. It is an aromatic hydrocarbon with lipophilic properties that easily crosses the blood-brain-barrier. Individuals with a history of substance use will often turn to PDCB-containing substances for the mild euphoria associated with it and because it will not be present on a routine drug screen. However, PDCB toxicity can cause long-lasting leukoencephalopathy and a panoply of symptoms including seizures, impassivity, memory loss, and agitation. It is important for physicians to be aware of this phenomenon so that they will be able to identify and manage patients with this constellation of symptoms.