Tacrolimus Induced Diabetes Presenting As Recurrent Pyelonephritis – A Rare Clinical Presentation

Tacrolimus is immunosuppressive agent used in a variety of skin disorders including vitiligo. Systemic Tacrolimus has been known to cause diabetes by inducing insulin resistance and increasing the activity and expression of glucose transporter , SGLT1 . In addition to this Tacrolimus has direct beta cell toxicity and subsequent insulin secretory defects. Although systemic absorption of tropical Tacrolimus is minimal but cases have been reported where tropical use of Tacrolimus has been associated with the blood levels above therapeutic range causing potential toxicity . Here we highlight a interesting case of a 22 year old female who was on treatment with Tacrolimus ointment for Segmental Vitiligo presented with features of pyelonephritis  with past history of similar recurrent episodes and on further investigations was diagnosed to have New Onset Diabetes Mellitus with elevated serum Tacrolimus levels suggesting Tacrolimus induced beta cell dysfunction and insulin resistance thus making it an interesting and rare presentation of potential toxicity.