Covid‐19 Histamine theory: Why antihistamines should be incorporated as the basic component in Covid‐19 management?

Pathologically, Histamine pathways has been found to significantly be able to modulate immune response and inflammation 6 hence cytokine storm, tissue response to inflammation, 7 coagulation process including deep vein thrombosis through Histamine H1 receptor 8,9 and can trigger acute symptoms due to its very rapid activity on vascular endothelium, bronchial and smooth muscles 10 and so forth. Some second generation antihistamines shows antiallergic and ant-inflammatory effects which outlined in one study 23 as through decrease in (1) production of cytokines by pro-inflammatory drugs and in the release of other mediators by mastocytes and basophils, (2) recruitment of eosinophils in the late phase of allergic reactions, (3) expression of membrane receptors in nasal epithelia cells and the vascular endothelium, particularly the leukocyte Intercellular Adhesion Molecule 1 (ICAM-1), which favors leukocyte migration form the blood to the respiratory mucosa and constitutes the main receptor for respiratory viruses to which the untreated atopic subject appear to be more susceptible. Since antihistamines seems to hold a crucial prognostic role in the management of Covid-19, there is a need to identify and repurpose some potential antihistamine drugs. TRANSPARENCY STATEMENT The lead author Harold L. Mashauri affirms that this manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.