Retrospective comparison of systemic treatments in the management of difficult areas in patients with psoriasis vulgaris

Objective:Psoriasis is a chronic, papulosquamous skin disease that can occur at any age, is commonly seen worldwide, and poses a significant health burden on both individuals and society. Especially in difficult-to-treat areas such as the nails, palmoplantar region, scalp, and genital area, psoriatic involvement can severely impair patients' quality of life. This retrospective study aimed to evaluate the responses of psoriasis vulgaris patients with difficult area involvement to various systemic treatment options. Materials and Methods: This study included patients who were retrospectively evaluated between October 1, 2023, and October 31, 2024, at the Department of Dermatology and Venereology, Faculty of Medicine, Karadeniz Technical University. Patients who had involvement of difficult areas (scalp, nails, genital, and palmoplantar) and received systemic treatment for psoriasis vulgaris were included. ICD codes L40.0 (psoriasis vulgaris) and L40.9 (unspecified psoriasis) were screened in the hospital system. A total of 1,605 patients were identified, and 267 patients with complete data and difficult area involvement were included in the study. The systemic treatments received (methotrexate, secukinumab, ixekizumab, risankizumab, and guselkumab) were evaluated retrospectively at weeks 0, 4, 12, and 24. Treatment effectiveness was assessed using Psoriasis Area and Severity Index (PASI), Dermatology Life Quality Index (DLQI), Nail Psoriasis Severity Index (NAPSI), and Physician's Global Assessment (PGA) scores for scalp, genital, and palmoplantar involvement. Additionally, data on skin, nail, and scalp findings, age, gender, height, weight, smoking/alcohol use, education level, marital status, age at disease onset, disease duration, family history, joint involvement, history of erythroderma, previous topical and systemic treatments, and phototherapy history were recorded. Results: A total of 267 patients aged between 9 and 85 years with psoriasis vulgaris were included. Among them, 141 (52.8%) were male and 126 (47.2%) were female. The mean age was 40.8±14. The mean BMI was 28.7±5.8; 105 (39.3%) were overweight and 97 (36.3%) were obese. The mean age of disease onset was 28.9±15.9 years, and the mean disease duration was 145±131.7 months. The most frequent difficult area involvements were scalp in 205 patients (76.8%), nails in 136 (50.9%), genital area in 104 (39.0%), and palmoplantar region in 93 (34.8%). Nail and genital involvement were significantly more common in males (p<0.001, p=0.042). Genital and scalp involvement were more common in patients with disease onset at ≤40 years (p<0.001 and p=0.001), whereas palmoplantar involvement was higher in patients over 40 years (p=0.038). In patients with psoriatic arthritis (PsA), nail involvement was more frequent (p=0.031), while scalp involvement was less common (p=0.007). The most frequent nail findings were onycholysis, 7 pitting, and oil drop signs. The treatments being used at the time of study were methotrexate in 89 patients (33.3%), secukinumab in 78 (29.2%), ixekizumab in 43 (16.1%), risankizumab in 37 (13.9%), and guselkumab in 20 (7.5%). At week 4, secukinumab demonstrated statistically significantly higher PASI75 response than risankizumab (p=0.009) and guselkumab (p=0.007). Ixekizumab was also statistically superior to guselkumab (p=0.025) and risankizumab (p=0.049) in terms of PASI75 response. For DLQI 0/1 scores, ixekizumab showed significantly better results compared to guselkumab (p=0.044). IL-17 inhibitors were more effective than IL-23 inhibitors in terms of PASI75 (p<0.001) and PASI90 (p=0.049) responses, and also showed statistically superior DLQI 0/1 scores (p=0.003). At week 12, secukinumab had significantly higher PASI75 (p=0.028), PASI90 (p=0.026), and PASI100 (p=0.016) responses compared to guselkumab. Ixekizumab showed significantly better DLQI 0/1 response than guselkumab (p=0.017). IL-17 inhibitors were superior to IL-23 inhibitors only in PASI100 scores at this time point (p=0.040). At week 24, ixekizumab achieved significantly better PASI100 response than guselkumab (p=0.019), and risankizumab was statistically superior to guselkumab in both PASI100 (p=0.003) and DLQI 0/1 (p=0.002) responses. Conclusion:IL-17 inhibitors stand out with their rapid onset of action, particularly in terms of early PASI responses, nail involvement, and improvements in quality of life. IL-23 inhibitors may provide more significant benefits in later stages, especially in PASI100 and DLQI responses. Evaluating treatment efficacy in difficult-to-treat areas such as the nails, scalp, genital, and palmoplantar regions is essential in clinical practice. Treatment decisions should be based not only on PASI scores but also on patient quality of life, the location of lesions, and individual clinical profiles.