Psoriasis is an inveterate, lasting and recurrent autoimmune ailment facilitated by deregulated immunologic responses from T-cells, dendritic cells and macrophages, which in turn leads to the unusual increase of keratinocytes in the epidermis (Hiraganahalli Bhaskarmurthy and Evan Prince, 2021). The condition is initiated by physical stress, medications, infections, smoking, hypertension, environmental factors, genetic factors, etc., that activate innate immunity (Prasannanjaneyulu et al., 2022). It is marked by well-developed red plaques with a silver scale resulting from the hyper-proliferation of keratinocytes, parakeratosis and dilation of dermal capillaries (Sabat et al., 2007). These plaques and scales vary in size and shape. Psoriatic lesions can appear as single or multiple lesions anywhere on the skin surface like elbow, knees, lower back and scalp (Yao et al., 2022).

According to estimates, psoriasis may affect 2–5% of the western inhabitants and costs the USA roughly $112 billion annually. Generally, the prevalence rate increases with latitude i.e., North Europe has a high prevalence rate, while East Asia often has the lowest (Schadler et al., 2019). Psoriasis prevalence for children varies between 0% and 2.1% in Taiwan and Italy respectively and for adults between 0.9% and 8.5% in US and Norway respectively, whereas the incidence of psoriasis seems to be higher in women, in contrast to males older than 18 years (Sunkari et al., 2019). In psoriasis, the 28-day cycle of epidermal cell reproduction and proliferation is drastically sped up to 4 days, with subsequent deposition of immature cells on the skin. Dead skin cells are lost from the skin surface once they reach the stratum corneum (Gelfant, 1976).

Conventional treatments like topical, systemic, phototherapy or combinations of conventional treatments for psoriasis have evolved enormously (Torsekar and Gautam, 2017). However, the majority of these conventional treatments led to undesirable adverse effects such as toxicity of organs, discomfort, broad-spectrum immunosuppression, skin cancer, hypertension and carcinogenicity linked with phototherapy and systemic approach which leads to the limitation of their long-term usage. Moreover, psoriasis frequently coexists with other illnesses like depression, cardiovascular disease and psoriatic arthritis (Li et al., 2019; Rahman et al., 2012). A bulk proportion of patients also develop pharmacoresistance after long-term drug exposure (Wu et al., 2015).

It takes several years to develop a new drug molecule from an idea in a lab to a product that can save lives and there is a very low success rate for the drug to be commercialized (Yamaguchi et al., 2021). Numerous investigations have been conducted to repurpose the existing drugs for treating psoriasis. Drugs that have already been licensed for the treatment of one disease or another are part of the current psoriasis management plan. A desirable strategy for investigating the possibility of medicines that have already gained approval for another indication in treating psoriasis is called drug repurposing (Rudrapal et al., 2020). Tofacitinib (Valenzuela et al., 2018), Baricitinib (K. A. K.A. Papp et al., 2016), Paclitaxel (Ehrlich et al., 2004), Simvastatin (Shirinsky and Shirinsky, 2007), Niclosamide (Thatikonda et al., 2020), Bexarotene (Smit et al., 2004) and other medications have been repurposed which block the psoriatic pathways (Jain et al., 2021). This review primarily focuses on the most current developments and learnings from clinical investigations into various routes and the medications that block these pathways. Food and Drug Administration (FDA) approved drugs for psoriasis since 2014 are shown in Fig. 1.