Management of unintentional methanol ingestions – Kids aren't little adults?

To the Editor:

Suicidal or malicious ingestions of methanol can potentially be fatal. Complications of severe poisoning include blindness, coma, and death.^1,2 Unintentional pediatric ingestions present diagnostic and treatment challenges often resulting in utilization of antidotal therapy, admission, and transfer to tertiary care centers with pediatric capabilities prior to confirmation of exposure. The aim of this study is to characterize and compare unintentional methanol ingestion in children with older patients.

Utilizing Crystal Reports (version 11.0), all methanol exposures reported to the Illinois Poison Center (2002–2011) were retrospectively searched. Only unintentional ingestions with a documented methanol concentration were queried for comparison. Patients were divided into two groups: ≤ 6 years of age and > 6 years of age. Intentional ingestions and patients without a documented methanol concentration were excluded from the study.

Twenty-four pediatric patients of ≤ 6 years of age met inclusion criteria. Ages ranged from 14 months to 5 years with an average of 28 months (54% female). Methanol concentrations were undetectable in 20 (83%) patients. The highest concentration obtained was 24 mg/dL. This patient had a second concentration of 16 mg/dL after treatment with fomepizole. Three other patients had detectable concentrations (5, 6, and 17 mg/dL). No patient was treated with ethanol or hemodialysis; however, 14 patients (58%) were empirically treated with fomepizole. Twelve patients were admitted to the hospital for a minimum of 24 h, and seven were transferred to a higher level of care.

By comparison, 35 patients were in the group that was > 6 years old. Ages ranged 9–68 years with an average of 37 years (69% male). Methanol concentrations were undetectable in 23 (64%) patients. The highest concentration obtained was 150 mg/dL. Three other patients had concentrations of 23, 35, and 47 mg/dL. However, all other patients had concentrations less than 10 mg/dL. Two patients were treated with ethanol, 21 (60%) were treated with fomepizole, and the patient with a concentration of 150 mg/dL received hemodialysis. Eleven patients were admitted to the hospital for at least 24 h.

Over 80% of our young pediatric unintentional exposures revealed that the child never ingested the product despite a history of probable ingestion. Detectable concentrations were insignificant and unlikely to cause harm. Comparatively, several unintentional exposures in older children and adults resulted in elevated methanol concentrations requiring focused therapy.

Several cases report young pediatric patients with significant methanol concentrations.^3–5 One report describes a 5-year-old male with a methanol concentration of 35 mg/dL who was asymptomatic and had no evidence of acidemia.⁴ Two other cases reported patients who were symptomatic or ill-appearing on initial presentation.^3,5

These retrospective data are limited exclusively to those patients reported to our regional poison center, and bicarbonate concentration, anion-gap, or pH measurements were not uniformly recorded. Additionally, coding errors may result in omission of pertinent data. Nevertheless, given these results, it may be reasonable to observe well-appearing and asymptomatic young children after an unintentional exploratory exposure and to follow serial chemistries for evidence of acidemia while awaiting results of a methanol concentration.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.