Use of paracetamol for fever in the first year of life was associated with an increased risk of asthma symptoms when aged 6â€“7 years (OR 1Â·46 [95% CI 1Â·36â€“1Â·56]). Current use of paracetamol was associated with a dose-dependent increased risk of asthma symptoms (1Â·61 [1Â·46â€“1Â·77] and 3Â·23 [2Â·91â€“3Â·60] for medium and high use vs no use, respectively). Use of paracetamol was similarly associated with the risk of severe asthma symptoms, with population-attributable risks between 22% and 38%. Paracetamol use, both in the first year of life and in children aged 6â€“7 years, was also associated with an increased risk of symptoms of rhinoconjunctivitis and eczema.
It’s been known for a long time that the interaction of NSAID COX inhibitors such as aspirin or paracetemol/acetominophen with the leukotriene pathway in humans can initiate asthma by shunting more of the 5-Lipo output down the LT pathway resulting in rapid adverse bronchial symptoms. However, this is the first time I’ve seen such strong evidence that skewing the pathway so early in post-natal development can produce measurable immunological effects several years down the development path.