Clinical characteristics of persistent ısotretinoin-associated ınflammatory back pain: a retrospective cohort study

Isotretinoin is commonly used to treat severe acne vulgaris, and reports of inflammatory back pain (IBP) during therapy have grown over the past decade. Previous studies have reported improvement in musculoskeletal symptoms following isotretinoin discontinuation; however, persistent symptoms have also been described. This study aimed to describe the clinical and demographic characteristics of isotretinoin-associated IBP according to symptom persistence after isotretinoin discontinuation.

This retrospective cohort study included 100 consecutive adults with new-onset IBP fulfilling ASAS criteria during isotretinoin therapy. Clinical, laboratory, and imaging data were collected. Patients were classified as persistent or non-persistent according to whether IBP continued beyond three months after isotretinoin discontinuation.

The median age was 24 years, and 80% of patients were women. IBP developed at a median of 2 months after isotretinoin initiation. Magnetic resonance imaging (MRI) showed bilateral sacroiliitis in 72% of patients, unilateral sacroiliitis in 20%, and normal findings in 8%. HLA-B27 positivity was uncommon (3/78). After isotretinoin discontinuation, 23 patients had persistent IBP and 77 had non-persistent IBP. Patients with persistent IBP had higher post-discontinuation BASDAI scores (median 5.05 vs. 2.00; p < 0.001), less BASDAI improvement (0.00 vs. 3.70; p < 0.001), more frequent Achilles enthesopathy (39.1% vs. 14.3%; p = 0.016), and more frequent sulfasalazine use (30.4% vs. 3.8%; p < 0.001).

Isotretinoin-associated IBP had a generally favorable course, with symptom improvement in most patients during follow-up, although symptoms persisted beyond three months in nearly one-quarter. Achilles enthesopathy at presentation was more frequent among patients with persistent IBP, suggesting that careful rheumatological follow-up may be particularly important in this subgroup.