Investigating the Real Effects of Isotretinoin on Enthesopathy in Acne Vulgaris Patients: A Prospective, Controlled Study

Abstract

Background: Isotretinoin is frequently used for treating severe, treatment-resistant, and scarring acne. A wide range of musculoskeletal side effects are reported due to isotretinoin, and one of them is enthesopathy. Objectives: In this study, we used ultrasound to evaluate tendon thickness and the presence of enthesophytes, erosions, calcifications, and bursitis. Overall, the main objective was to determine the effects of isotretinoin on enthesopathy. Methods: The study included 30 patients diagnosed with acne vulgaris (AV) and on isotretinoin treatment for ≥3 months. Thirty patients with AV without treatment or on topical treatments were included as the control group. In both groups, 5 areas in the lower limb were examined bilaterally for tendon thickness, erosion, calcifications, enthesophytes, and bursitis and compared among themselves. Moreover, the Glasgow Ultrasonographic Enthesitis Scoring System (GUESS) scores were also calculated and compared between the 2 groups. Results: The quadriceps tendon, distal patellar ligament, and right Achilles tendon thicknesses were statistically higher in the isotretinoin group than in the control group ( P = .02, P = .03, P = .04). The GUESS score was also statistically higher in the isotretinoin group ( P = .02). Conclusion: This study showed that isotretinoin has certain effects on tendon thickness. Clinicians should be alert that patients under isotretinoin treatment may develop enthesopathy even with no clinical signs.