Objectives: to analyse the main effects of melatonin dietary supplementation in different pathologies. Method: systematic review related to the use of melatonin as a dietary supplement and its effects on PubMed, CINAHL, Scopus, ProQuest Health and Medical Complete, Scielo and Dialnet databases. Results: the 613 obtained articles at baseline were finally reduced to 19 after the application of inclusion and exclusion criteria and the reverse search. Melatonin supplementation has shown its benefits in sleep disorders, aging, various chronic diseases and anthropometry. Conclusions: the known benefits of melatonin are regulating the sleep-wake cycle and preventing oxidative stress of multiple health-disease processes. However, more research is needed to determine its applicability in numerous pathologies.

A 29-year old female patient suffered a hypersensitivity reaction after having a tattoo placed on the supramalleolar area of her right-leg. Among other substances, the tattoo ink used contained red dye. Since the allergic reaction and its subsequent complications were refractory to conventional medical treatment, it was finally necessary to surgically remove the tattoo and cover the area with an autograft.