Post kala-azar dermal leishmaniasis: an unresolved mystery

•Sodium antimony gluconate contributes towards the pathogenesis of PKDL.•UV light plays a pivotal role in the development of PKDL.•Development of PKDL can be viewed as a reinfection or activation of latent Leishmania parasites.•PKDL can be resolved by mounting an effective tissue-specific memory T cell response.•Host genetic factors play a contributory role. Post kala-azar dermal leishmaniasis (PKDL), a cutaneous sequela of visceral leishmaniasis (VL), develops in some patients alongside but more commonly after apparent cure from VL. In view of the pivotal role of PKDL patients in the transmission of VL, here we review clinical, epidemiological, parasitological, and immunological perspectives of this disease, focusing on five hypotheses to explain the development of PKDL: (i) the role of antimonial drugs; (ii) UV-induced…