Mothballs are either napthalene (which can be toxic) or paradichlorobenzene (ingestion usually inconsequential). One can determine which ingredient is in the mothballs by placing the mothball in 4 ounces of tepid water in which 3 heaping tablespoonsfuls of salt have been dissolved. A napthalene mothball will float whereas a paradichlorobenzene mothball will sink.
Napthalene can cause hemolytici activity, acute tubular necrosis, and methemoglobinemia. Less than one mothball can cause hemolysis in patients with G6PD deficiency. Infants are also more susceptible to toxicity due to inadequate conjugation of toxic metabolites.
Children who ingest napthalene may present with nausea, vomiting, abdominal pain and diarrhea. Lab includes a CBC with a peripheral smear, LFTs, renal function, urine free hemoglobin, and methemoblobin concentration. Treatment is supportive.
Children who ingest paradichlorobenzene may present with nausea and vomiting. Symptoms are self-limited and treatment is supportive.