Isotretinoin-Induced Hematuria in Acne Patients: Frequency, Risk Factors, and Management Recommendations from a Single-Center Study

Introduction: Isotretinoin-induced hematuria is very rare; it has been reported in one study and individual case reports but never proven statistically. Objectives: To determine whether hematuria is statistically more significant in isotretinoin-treated acne patients than in non-isotretinoin-treated patients. Methods: Cohort study of acne patients treated at the University Clinic of Dermatology between 01 September 2022 and 31 March 2024.  Results: Eight hundred and sixty-four acne patients were treated and reviewed; 69.3% (599/864) were treated with modalities other than isotretinoin, while 30.7% (265/864) were treated with isotretinoin. Of the isotretinoin patients, only 26% (69/265) had urinalysis done at least once during therapy. In the isotretinoin group, 13% (9/69) had at least one episode of hematuria during treatment, as did 2.9% (2/70) in the control group. Hematuria is significantly more frequent in the isotretinoin group compared to control (P=0.026), with a 5.1 (95% confidence interval (CI): 1.06–24.5) higher risk. Of the isotretinoin-induced hematuria patients, 66.6% were male. The mean duration of isotretinoin use for hematuria was 2.78 months. Comorbidities and minimal and maximal isotretinoin dosage were not correlated with hematuria. Conclusion: Hematuria is significantly more frequent in patients on isotretinoin and is a side-effect of isotretinoin. In the majority of cases, isotretinoin should be continued. Patients should be stratified according to risk factors per guidelines for microhematuria and referred to urologists. Urinalysis should be a part of routine monitoring in patients on isotretinoin especially  at the 2- and 4-month intervals.