[HAIR STRAIGHTENING - NOT STRAIGHTFORWARD].

The rising popularity of hair straightening in younger ages has become a medical issue, since glycolic acid and formaldehyde may be present, even in "formaldehyde-free" labeled products. Formaldehyde - a colorless material, evaporates during the hair straightening procedure, inhaled and absorbed into the blood stream causing oxidative stress and cytotoxic damage to the proximal tubule cells leading to acute kidney injury (AKI). Glycolic acid is processed to glyoxylate and eventually to oxalate, whose deposition may also cause AKI. We present three cases of female teenagers with AKI, recently after a hair straightening procedures. All patients had features of tubular damage and kidney biopsies in the first 2 cases showed acute tubular necrosis (ATN), one with oxalate deposition and the other with unidentified depositions. Two cases required acute dialysis, and shortly after commencing it, kidney function rapidly improved. We believe that in the presented cases, the prompt dialysis cleared a nephrotoxic ingredient, allowing improvement of renal function, therefore preventing long-standing and maybe, even permanent damage. This case presentation highlights the danger of hair straightening products in pediatric populations aiming to increase its index of suspicion among adult and pediatric nephrologists.