Acute Kidney Injury Following the Use of a Hair-Straightening Product

Abstract

Hair-straightening treatments have become increasingly popular worldwide. Following concerns regarding the toxicity of formaldehyde-containing formulations, alternative compounds have been increasingly incorporated into commercially available hair-straightening products. However, accumulating evidence suggests that some of these products may be associated with acute kidney injury (AKI). We report the case of a 37-year-old woman with no history of hypertension, diabetes, or kidney disease who developed severe AKI shortly after undergoing a hair-straightening treatment. One day after undergoing the hair-straightening procedure, she developed abdominal pain, repeated vomiting, constipation, and asthenia. Laboratory investigations confirmed severe AKI. Urinalysis revealed minimal proteinuria, sterile urine culture, and no urinary casts or urinary crystals. Renal ultrasonography demonstrated normal-sized kidneys with preserved corticomedullary differentiation and no hydronephrosis or nephrolithiasis. The patient was admitted 4 days after the hair-straightening procedure, at which time serum creatinine had reached 492 µmol/L (5.56 mg/dL). She received conservative treatment with intravenous isotonic saline hydration, resulting in rapid recovery of kidney function. Serum creatinine decreased to 146 µmol/L (1.65 mg/dL) at discharge (11 days after the procedure), 117 µmol/L (1.32 mg/dL) at the first outpatient follow-up (19 days after the procedure), and normalized to 88 µmol/L (0.99 mg/dL) at the final follow-up (26 days after the procedure). Renal biopsy and urinary oxalate measurements were not performed because of the patient’s favorable clinical course. Although repeated vomiting may have contributed to volume depletion, the close temporal relationship between cosmetic exposure and symptom onset, the exclusion of alternative causes of AKI, and the complete recovery following supportive treatment support a probable causal relationship. This case further supports the growing evidence that hair-straightening products may cause severe but reversible AKI and highlights the importance of investigating recent cosmetic exposure in patients presenting with otherwise unexplained AKI. Early recognition and supportive management may contribute to favorable renal outcomes.