Comparison of efficacy of 4% diclofenac sodium gel and 0.1% tazarotene cream for seborrheic keratosis with clinical and dermoscopic evidence

Objectives: To compare and evaluate the efficacy and safety of 4% diclofenac sodium gel and 0.1% tazarotene cream in the treatment of seborrheic keratosis (SK) and dermatosis papulosa nigra (DPN) using clinical and dermoscopic assessment. Materials and Methods: A prospective comparative study was conducted on 36 patients diagnosed with SK and DPN attending the Dermatology Outpatient Department of Rajaboina Venkataiah Memorial Institute of Medical Sciences and Research Centre. Patients were equally allocated into two groups: Group A received 4% diclofenac sodium gel and Group B received 0.1% tazarotene cream. Treatment was continued for 20 weeks with follow-up assessments at 4-week intervals. Clinical evaluation was performed using the physician lesion assessment (PLA) score, lesion size, and lesion count. Dermoscopic features were documented at baseline and during follow-up. Patient satisfaction and adverse effects were also assessed. Results: The study included 19 females (52.8%) and 17 males (47.2%), with an age range of 35–65 years. Both treatment groups demonstrated progressive improvement in lesion number, size, and PLA scores over the study period. In the diclofenac group, the mean PLA score decreased from 2.0 at baseline to 1.44 at 20 weeks, representing a 28% reduction, while the mean lesion size decreased from 1.33 cm to 1.0 cm (16.5% reduction). In the tazarotene group, the mean PLA score decreased from 2.0 to 1.56 (22% reduction), while the mean lesion size decreased from 1.67 cm to 1.25 cm (21% reduction). Patient satisfaction was higher in the diclofenac group, with 55.5% reporting high satisfaction compared to 11.1% in the tazarotene group. Diclofenac was also better tolerated, with 55.5% of patients reporting no adverse effects, whereas mild erythema, irritation, and peeling were more common with tazarotene. Conclusion: Both 4% diclofenac sodium gel and 0.1% tazarotene cream were effective in the treatment of SK and DPN. Diclofenac sodium gel demonstrated greater improvement in PLA scores, superior tolerability, and higher patient satisfaction, whereas tazarotene cream showed a slightly greater reduction in lesion size. Diclofenac may therefore represent a safer and more patient-friendly topical treatment option. Larger studies with longer follow-up periods are required to confirm these findings and assess long-term outcomes.