Allergic disorders encompass skin, food and respiratory allergies. Study present here includes plant metabolites like Polyphenols, Quercetin, Gossypin, Saponin, Steroidal lactone, alkaloids and many others are such class of compounds that are found in foods and plant sources and have been investigated for their anti‐allergic, antihistamine and anti-inflammatory properties. These plants display their antiallergic potential through affecting mast cell, immunoglobulin, histamine and inhibiting different cytokines and interleukins. Research into repositioning known drugs to treat off target diseases other than the originally intended disease continues to grow and develop for therapeutic purposes. Phytoconstituents and the recent knowledge about SARS-CoV and SARS-CoV-2 pathology, profess their use in the prevention and management of COVID-19 pandemic. It is, therefore, believed to be an emerging strategy where existing plant metabolites having already been tested safe in humans, are redirected based on a valid target molecule to combat particularly, rare, neglected and difficult-to-treat diseases.