title: The association between paracetamol and asthma is still under debate.
abstract: To analyse the relationship between paracetamol and asthma.
  
  
  
  An English literature search using electronic search engines (PubMed and EMBASE) was conducted.
  
  
  
  Articles published in peer-review journals, from 1990 to December 2015 were included. To perform the search for the most suitable and representative articles, keywords were selected ("asthma," "paracetamol" and "acetaminophen"). The evidence level was rated according to the criteria of the Oxford Centre For Evidence-Based Medicine.
  
  
  
  The exposure to paracetamol during pregnancy was analysed in several cohort studies, showing an association between the prenatal exposure to paracetamol with suffering from asthma or presence of wheezing in childhood, especially for persistent wheezing. Nevertheless, a recent study concluded that the relationship between asthma and paracetamol is explained, at least in part, by confounding factors. Several works have also associated the exposure to paracetamol in the first years of life or in adults with the development of childhood asthma. Several pathophysiological mechanisms are known that could explain this relationship, such as the glutathione pathway, the decrease in the release of Th1 cytokines that are normally produced during febrile episodes, which would then lead to a predominance of Th2 cytokines, the cytotoxic effect of paracetamol for pneumocytes, a modulator effect on the activity of myeloperoxidase, as well as the possible antigenic effect of paracetamol, mediated by IgE.
  
  
  
  There are many arguments that suggest a relationship between the use of paracetamol with the appearance of asthmatic symptoms, however the evidence is inconclusive.
authors: a Department of Respiratory Medicine - University Hospital of Santiago de Compostela , Spain.
authors: Tamara
authors: T
authors: Lourido-Cebreiro
authors: b Spanish Biomedical Research Networking Centre-CIBERES , Madrid , Spain.|c Department of Biochemistry and Molecular Biology , Faculty of Biology/CIBUS University of Santiago de Compostela , Spain.
authors: Francisco-Javier
authors: FJ
authors: Salgado
authors: a Department of Respiratory Medicine - University Hospital of Santiago de Compostela , Spain.|d Department of Medicine - University of Santiago de Compostela , Spain.|e Health Research Institute of Santiago de Compostela (IDIS) , Spain.
authors: Luis
authors: L
authors: Valdes
authors: a Department of Respiratory Medicine - University Hospital of Santiago de Compostela , Spain.|b Spanish Biomedical Research Networking Centre-CIBERES , Madrid , Spain.|d Department of Medicine - University of Santiago de Compostela , Spain.|e Health Research Institute of Santiago de Compostela (IDIS) , Spain.
authors: Francisco-Javier
authors: FJ
authors: Gonzalez-Barcala
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects*; D001249:Asthma / Q000453:epidemiology*; D002675:Child, Preschool; D005260:Female; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009195:Peroxidase / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology; D012135:Respiratory Sounds
chemical_list: D000082:Acetaminophen; D009195:Peroxidase; D005978:Glutathione
keywords: Pathophysiology; epidemiology; mechanisms; morbidity and mortality; reviews