Alopecia Universalis After Sitagliptin Intake

A 64-year-old patient developed alopecia universalis one month after starting treatment with Sitagliptin, a Dipeptidylpeptidase-4 (DPP-4) inhibitor, and Metformin for diabetes. The patient's medication was switched to Sitagliptin from a different manufacturer and Dapagliflozin. On advice, Sitagliptin was discontinued and treatment continued with only Dapagliflozin. However, due to insufficient diabetes control, Sitagliptin therapy was reintroduced after 6 weeks, and the alopecia persisted. The authors suspect an association between DPP-4 inhibition and alopecia due to the immunological interaction potential of DPP-4, which can both inhibit and activate the immune system. The brief period without therapy was deemed too short to observe any potential hair regrowth.