Severe Nail Fold Psoriasis Extending from Nail Psoriasis Resolved with Ustekinumab: Suggestion of a Cytokine Overflow Theory in the Nail Unit

Nail Psoriasis: Clinical Features and Severity Assessment

The nail is an important characteristic in the context of psoriasis. Nail psoriasis exhibits several clinical manifestations. Since the development of the Nail Psoriasis Severity Index (NAPSI) score assessment tool for evaluating the severity of nail psoriasis, nail matrix symptoms such as pitting, leukonychia, crumbling, and red spots have been observed in the lunula. Nail bed symptoms include onycholysis, subungual hyperkeratosis, oil spots, and splinter hemorrhage. However, Beau's lines and nail fold psoriasis, which are not included in this assessment tool, should be considered essential symptoms for indicating the activity of nail psoriasis. Although NAPSI is the most widely used tool for assessing the severity of nail psoriasis, it has uncontrolled limitations. Although other assessment tools have been developed, none have successfully replaced the NAPSI. In clinical trials for nail psoriasis, the NAPSI is used in various forms, such as improvement rates, changes in the mean NAPSI score, and achievement rates of NAPSI 75. Consequently, caution is warranted when interpreting the clinical trial results related to nail psoriasis improvement.

Nail Psoriasis: An Updated Review of Currently Available Systemic Treatments

Background

Nail psoriasis (NP) has a prevalence that ranges from 10 to 82% among patients with psoriasis (PsO) and is one of the most common difficult to treat site of psoriasis. We performed a thorough review of the literature, exploring evidence regarding all available NP systemic treatments, describing also in detail NP dedicated clinical trials.

Methods

A literature search was conducted in PubMed and Embase prior to February 2023 using a combination of the terms "nail" AND "psoriasis" AND "systemic therapy" AND/OR "systemic treatment". A total of 47 original studies and case reports were reviewed in this article.

Results

Systemic therapies should be considered when the disorder involves more than 3 nails, has extensive skin and joint involvement, and has a significant impact on QoL, due to their best long-term efficacy. In detail, conventional and biologic systemic drugs demonstrated efficacy in recent trials, including acitretin, methotrexate, cyclosporine, apremilast, adalimumab, infliximab, etanercept, certolizumab, golimumab, ustekinumab, secukinumab, ixekizumab, brodalumab, bimekizumab, guselkumab, risankizumab and tildrakizumab.

Conclusion

Several therapies have demonstrated efficacy and safety in the treatment of NP; however, the choice of treatment depends not only on the severity of the nail involvement, but also on whether PsA is present, the patient's comorbidities other than PsA, previous treatment history, and the patient's drug preferences.

Toenail Psoriasis during Ustekinumab Therapy: Results and Limitations

Background

Nail psoriasis is a common clinically significant symptom of psoriasis. However, few studies have focused on the characteristics and course of toenail psoriasis.

Objective

To investigate the treatment response of toenail psoriasis during a 52-week period of ustekinumab use.

Methods

Patients were evaluated using the Nail Psoriasis Severity Index (NAPSI) at every injection visit. NAPSI score changes throughout the treatment were analyzed. The treatment response in each toenail and each NAPSI characteristic was also analyzed.

Results

A total of 22 patients with chronic plaque psoriasis with concomitant toenail psoriasis were examined. Several characteristics such as ridging or onychomycosis that mimic psoriasis or hinder the evaluation were identified. NAPSI significantly improved during the treatment (p<0.05). The big and second toes were significantly improved after 52 weeks of ustekinumab treatment (p<0.05). Pitting and oil-drop discoloration were the only two characteristics that showed significant changes post-treatment (p<0.05).

Conclusion

Ustekinumab proved to be efficacious in treating toenail psoriasis. Because of the factors that hinder the NAPSI scoring, only NAPSI scores of the first and second toes can be used.

Overview of the molecular determinants contributing to the expression of Psoriasis and Psoriatic Arthritis phenotypes

Psoriasis and psoriatic arthritis are multifactorial chronic disorders whose etiopathogenesis essentially derives from the alteration of several signalling pathways and the co-occurrence of genetic, epigenetic and non-genetic susceptibility factors that altogether affect the functional and structural property of the skin. Although shared and differential susceptibility genes and molecular pathways are known to contribute to the onset of pathological phenotypes, further research is needed to dissect the molecular causes of psoriatic disease and its progression towards Psoriatic Arthritis. This review will therefore be addressed to explore differences and similarities in the etiopathogenesis and progression of both disorders, with a particular focus on genes involved in the maintenance of the skin structure and integrity (keratins and collagens), modulation of patterns of recognition (through Toll-like receptors and dectin-1) and immuno-inflammatory response (by NLRP3-dependent inflammasome) to microbial pathogens. In addition, special emphasis will be given to the contribution of epigenetic elements (methylation pattern, non-coding RNAs, chromatin modifiers and 3D genome organization) to the etiopathogenesis and progression of psoriasis and psoriatic arthritis. The evidence discussed in this review highlights how the knowledge of patients' clinical and (epi)genomic make-up could be helpful for improving the available therapeutic strategies for psoriasis and psoriatic arthritis treatment.

Evidence and Suggested Therapeutic Approach in Psoriasis of Difficult-to-treat Areas: Palmoplantar Psoriasis, Nail Psoriasis, Scalp Psoriasis, and Intertriginous Psoriasis

Psoriasis is resistant to treatment and it shows frequent relapse; systemic treatment is often associated with toxicities, and long-term safety data are lacking for most of the newer drugs like biologics. Moreover, some body areas such as hands, feet, intertriginous areas, scalp, and nails are even more resistant. Frequently, systemic treatments are necessary considering the higher psychological impact on the patient. There is a lack of agreement on the best therapeutic modalities in the management of psoriasis involving difficult-to-treat locations. At present, there are no Indian guidelines for these conditions. Available literature has been reviewed extensively on the treatment of psoriasis involving difficult-to-treat locations; level of evidence has been evaluated as per the Oxford Centre for Evidence-Based Medicine 2011 guideline, and therapeutic suggestions have been developed. Best care has been employed to consider socioeconomic, cultural, genetic, and ethnic factors to prepare a therapeutic suggestion that is appropriate and logical to be used among Indian population and people of similar ethnic and socioeconomic background.