There is an increased risk of skin cancer following PUVA, shown by both US and European studies. The greater risk measured by the US studies may be at least partly explained by high UVA dose exposure and the lighter phototypes of the treated patients. The lack of prospective studies in psoriasis patients treated with NB-UVB constitutes a barrier to the robust assessment of carcinogenic risk of this phototherapy technique.

Literature data about topical treatment adherence are heterogeneous and scarce. They confirm the limited topical treatment adherence in psoriasis in real life, much lower than what is reported in randomized controlled trials. Therapeutic education and clear instructions on the use of topical agents are necessary to improve adherence. Studies are needed to identify predictors of limited adherence and to identify interventions improving adherence to topical medications in psoriasis.

These recommendations for the use of topical agents and phototherapy in psoriasis are evidence-based and supported by a panel of dermatologists. The next step will be to disseminate these recommendations and assess the opinion of physicians who were not involved in generating the recommendations.

The literature analysis on topical steroids in psoriasis is reassuring although the quality of safety studies is limited with a majority of short-term studies. Although short-term biological effects of topical steroids on the HPA axis were observed in several clinical studies, they were not associated with clinical signs. Adequately designed long-term studies would be necessary to better determine the risk of skin atrophy using modern methods of evaluation such as dermoscopy and echography.

PUVA and NB-UVB are both effective therapies in treatment of psoriasis. Our results suggest that compared with NB-UVB, PUVA tends to clear psoriasis more reliably, with fewer sessions, and provides with longer lasting clearance. However, the long-term safety of PUVA, especially its cutaneous carcinogenic risk, and the easier administration procedure often lead dermatologists to prefer NB-UVB as first line phototherapy treatment in plaque type psoriasis.

Although cemiplimab has been approved for locally advanced (la) and metastatic (m) cutaneous squamous-cell carcinomas (CSCCs), its real-life value has not yet been demonstrated. An early-access program enrolled patients with la/mCSCCs to receive cemiplimab. Endpoints were best overall response rate (BOR), progression-free survival (PFS), overall survival (OS), duration of response (DOR) and safety. The 245 patients (mean age 77 years, 73% male, 49% prior systemic treatment, 24% immunocompromised, 27% Eastern Cooperative Oncology Group performance status (PS) ≥ 2) had laCSCCs (35%) or mCSCCs (65%). For the 240 recipients of ≥1 infusion(s), the BOR was 50.4% (complete, 21%; partial, 29%). With median follow-up at 12.6 months, median PFS was 7.9 months, and median OS and DOR were not reached. One-year OS was 73% versus 36%, respectively, for patients with PS < 2 versus ≥ 2. Multivariate analysis retained PS ≥ 2 as being associated during the first 6 months with PFS and OS. Head-and-neck location was associated with longer PFS. Immune status had no impact. Severe treatment-related adverse events occurred in 9% of the patients, including one death from toxic epidermal necrolysis. Cemiplimab real-life safety and efficacy support its use for la/mCSCCs. Patients with PS ≥ 2 benefited less from cemiplimab, but it might represent an option for immunocompromised patients.

The clinical development of topical steroids in psoriasis did not follow state of the art modern methodology. Treatment success appears to be highly variable across studies. Maintenance intermittent treatment appears to be useful to prolong remission. Recommendations concerning topical steroids treatment modalities in plaque psoriasis should be mostly based on expert opinion.

VDS is twice more effective than VD and displays a better cost per success. Additional studies are needed to clarify maintenance treatment, impact on quality of life, treatment of non-plaque psoriasis. It will be important to harmonize outcome measures in future studies with topical agents in psoriasis to better appraise their efficacy.