Introduction
Non-steroidal anti-inflammatory drugs (NSAIDs) and other eicosanoid
pathway modifiers are one of the most frequently used anti-inflammatory
medications worldwide against infections, other acute and chronic
inflammatory diseases and pain. Eicosanoids, including prostaglandins
(PGs), leukotrienes (LTs), thromboxanes (TXs), hydroxyeicosatetraenoic
acids (HETEs), lipoxins (LXs), and many recently proposed pro-resolving
mediators constitute a wide range of active lipid mediators possessing
pro- and anti-inflammatory, as well as pro-resolution
properties.1 They are products of the major
unsaturated fatty acids: arachidonic acid (AA), dihomo-γ-linolenic acid
(DHGLA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA),
metabolized in three main pathways: cyclooxygenase (COX), lipoxygenase
(LO or LOX) and cytochrome P450 (Fig. 1) . Those active lipid
mediators play substantial roles in the development and resolution of
inflammation, including allergic and viral inflammation, which we have
reviewed extensively in the previous report.1 Even
though NSAIDs and other eicosanoid pathway modifiers are so commonly
consumed and are relatively safe for the majority of people, the current
pandemic of the severe acute respiratory syndrome coronavirus-2
(SARS-CoV-2) revealed substantial knowledge gaps in understanding their
modes of action, benefits and risks related to their use in patients
with respiratory and allergic diseases. Unfortunately, this resulted in
the conflicting messages sent to the public from the scientific
community. Therefore, we, the European Academy of Allergy and Clinical
Immunology Task Force (EAACI TF) on Eicosanoids, here critically review
the most recent findings on the roles of NSAIDs, leukotriene antagonists
(LTRAs), prostaglandin D2 (PGD2)
receptor antagonists and cannabinoids, as well as we summarize their
selectivity, and additional modes of actions in allergic airway
diseases, drug allergy and respiratory virus infections. In addition, we
also describe here the effects of novel T2 biologicals used in allergic
diseases on eicosanoid pathways.