Nail psoriasis may be early PsA predictor

Patients with nail psoriasis may be more likely to develop psoriatic arthritis and should be closely monitored for predictive signs, according to a study.

“The nail is connected to underlying bone via an enthesis network that is fused with the extensor tendon crossing the distal interphalangeal joint,” Gurjit S. Kaeley, MRCP, of the department of medicine, division of rheumatology, University of Florida College of Medicine, and colleagues wrote in Journal of Rheumatology. “This anatomical connection of the nail matrix to the musculoskeletal system means that NP can be an early indicator of PsA; therefore, there is a need for awareness and understanding of nail disease among rheumatologists, primary care providers and dermatologists to improve identification and management of PsA.”

Researchers completed a literature search of nail psoriasis (NP) systemic therapies in psoriatic disease, finding topical therapies to be the most often used, despite modest efficacy.

Intralesional corticosteroid or methotrexate injections have shown greater efficacy but are unpopular due to pain and time constraints. Oral therapies such as cyclosporine, methotrexate, acitretin and leflunomide are modestly effective, with many prescribers reluctant to use them without significant skin disease as well, the study said.

Biologic treatments, while effective in psoriasis and psoriatic arthritis, are not indicated for nail psoriasis, leading to possible reimbursement challenges.

In 66 clinical studies that evaluated nail psoriasis outcomes, nail measures were a primary outcome in 22 articles, a secondary outcome in 25, and a retrospective or post hoc outcome in 19.

While the Nail Psoriasis Severity Index was used in most trials to measure severity, it is not a standardized index.

“It is important for rheumatologists and dermatologists to accurately diagnose and treat NP to potentially delay the onset and progression of joint disease,” the authors wrote. “However, given that systemic therapies are not specifically indicated for the treatment of NP in the absence of moderate to severe skin or joint disease, there are several unmet needs in daily practice, including the lack of a simple, validated and widely accepted NP scoring system and well-defined treatment guidelines for patients with NP without moderate or severe skin symptoms or active PsA.”