The unknown silent drug reaction in acne patients: rare case of isotretinoin-induced haematuria.

Background: Acne vulgaris is one of the most frequent visits to primary care physicians and dermatologists alike. Isotretinoin is the backbone of acne treatment. In most countries, depending on the health care system, isotretinoin is prescribed by dermatologists but primary care physicians are a part of the follow-up and interpreting analysis. Adverse effects of isotretinoin on the kidney and urinary system are mostly limited to sparse case reports. Specifically, gross and microscopic haematuria is not mentioned to be associated with isotretinoin. Lack of data regarding these adverse effects can lead to doubt regarding further patient management not only with dermatologists but also primary care physicians.

Objective: We report a 16-year-old male patient with isotretinoin-induced haematuria with multiple episodes and subsequent challenge and de-challenge. No personal or familial history of nephrological disease was present. Ultrasound imaging and nephrology workup was within normal limits. Other aetiologies were excluded. Nephrology consult stated there was no contraindication for isotretinoin use and was reinstated at 0.6 m/kg/day. More frequent observation was indicated until completion of isotretinoin.

Conclusion: Our case raises awareness to other dermatologists and primary care physicians that haematuria can be secondary to isotretinoin but not a contraindication for further use if asymptomatic and microscopic. More extensive evaluation and monitoring should be done if the patient is symptomatic with other abnormalities and symptoms. Urinalysis should be a part of routine follow-up monitoring in patients on isotretinoin. Furthermore, delineating and differentiating when to refer to a nephrologist is essential for physicians, patients, and the health care system overall.