In the January 2010 issue of Medical Hypothesis, Becker and Schultz suggest that Tylenol may be implicated in both autism and asthma.
The rate of these conditions has risen sharply in recent years but there continues to be controversy. Little hard evidence exists but one study describes the significant increase in autism that began at the same time acetaminophen was recommended to take the place of aspirin.
One preliminary case controlled study provides some confirmation with respect to Tylenol. The study found a significant increase in autism among children given acetaminophen for symptoms associated with the measles-mumps-rubella vaccination. The group of children given Ibuprofen for the same symptoms of the vaccination were significantly less likely to be autistic. The use of Tylenol by pregnant women is also thought to be associated with autism at birth. These studies also bring into question the relative danger of vaccinations as acetaminophen may be the responsible agent for cases of autism and not the vaccination itself.
The speculation regarding the etiology of both autism and asthma will no doubt continue for some time until larger and better studies are conducted. In the mean time there is a small dose of evidence and a heavy dose of speculation regarding the etiologies of these conditions.