A normal or noncontributory anatomical examination did not exclude diphenhydramine poisoning in five reported infant deaths. The investigators combined postmortem toxicology with scene information, other examinations and, in two cases, admissions of administration. The report did not establish that any positive drug finding automatically determines cause of death.
Five infants with otherwise unexplained deaths
Baker and colleagues described infants aged six, eight, nine, twelve and twelve weeks. This was a selected five-case report, not a consecutive population survey, controlled dosing study or estimate of poisoning prevalence. The infants could not have independently obtained and administered the medication.
Gross examinations found no natural disease or injury explaining death. Microscopy and other investigations were negative or noncontributory, apart from pulmonary congestion noted in the six-week-old. The absence of a diagnostic lesion did not establish a nontoxicological explanation.
The postmortem blood diphenhydramine results were 1.6 mg/L at six weeks, 1.5 mg/L at eight weeks, 1.6 mg/L at nine weeks, and 1.1 mg/L in each twelve-week-old. These measured concentrations were observations from individual deaths, not validated age-specific thresholds.
The evidence was more than an unexplained number
In the nine-week-old’s case, the father subsequently admitted administering a diphenhydramine-containing sleep aid to make the child sleep. That history supplied exposure information independently of the blood measurement. The report did not provide a controlled reconstruction of the absorbed dose from that concentration.
In one twelve-week-old’s case, the daycare provider admitted administering diphenhydramine. A feeding bottle also tested positive despite having been cleaned and dried before police seized it. This corroborated exposure; it did not measure the concentration in the bottle before cleaning or the amount the infant consumed.
Only two of the five investigations had an admission of administration. The absence of an admission in the others was not equivalent to a negative toxicology result. Equally, a drug result could not identify a particular administrator without additional evidence.
Why an initial SIDS interpretation could change
The eight-week-old’s death was initially classified as sudden infant death syndrome. After a blood result of 1.5 mg/L, the reported cause was amended to diphenhydramine intoxication. Another case was initially pending and believed to be SIDS before toxicology contributed to a poisoning conclusion.
The authors attributed all five deaths to diphenhydramine after considering the entire investigation. They discussed and rejected an incidental-drug explanation in these cases. That was their case assessment; the series did not validate an automatic rule replacing investigation with a concentration cutoff.
Specimen and method limits remain important
Table 1 identified heart blood at 1.5 mg/L and inferior vena cava blood at 1.3 mg/L in the eight-week-old. Most other blood sites were unspecified. The paper did not provide a uniform death-to-collection interval, detailed storage history, analytical validation, detection limit or quantification limit for all five cases.
Drug and volatile screening was performed. No other substances were detected except trace desmethyldiphenhydramine in one case. That statement describes the reported testing; it is not proof that every possible toxicant was excluded.
Additional results included brain and liver in one infant, spleen, liver and kidney in another, and urine and vitreous in the nine-week-old. Tissue concentrations used mg/kg and fluids mg/L. None supplied a validated blood-equivalent conversion or recovered concentration during life.
What the report supports
The authors argued that toxicology should be part of unexplained infant-death investigations because anatomical examination alone can miss a poisoning explanation. They did not estimate the frequency of such events or directly demonstrate the terminal physiological mechanism in each infant.
Preserve the specimen site, measured result, analytical scope and independent exposure evidence. Neither normal anatomy nor drug detection alone settles causation. A separate, later series illustrates the contrasting problem of diphenhydramine detections considered incidental in some pediatric deaths.
Primary source
Baker AM, Johnson DG, Levisky JA, et al. Fatal Diphenhydramine Intoxication in Infants. Journal of Forensic Sciences. 2003;48(2). doi:10.1520/JFS2002121.
Leave a Reply