Unequal relevance between different subtypes of fingernail psoriasis and psoriatic arthritis.

Nail disease in psoriasis has been found to be associated with psoriatic arthritis (PsA); however, which subtype of nail disease holds greater relevance to PsA remains unclear. This study was performed to explore the associations between three subtypes of fingernail disease (pitting, onycholysis, and hyperkeratosis) and PsA among patients with psoriasis. Patients with psoriasis attending five dermatology clinics in Shanghai between January 2020 and May 2021 were examined for skin, joint, and fingernail changes. Multivariate logistic regression analyses were utilized to test the strength of associations between subtypes of fingernail disease and PsA. The receiver operator characteristic (ROC) curve with area under curve (AUC) was used to evaluate their accuracies in diagnosing PsA. Sensitivity and specificity were also calculated. Of 1985 patients with psoriasis included, 228 (11.5%) patients were diagnosed with PsA, and the remaining patients were cutaneous-only psoriasis (PsC). One-hundred and fifty-seven (68.9%) patients with PsA and 748 (42.6%) patients with PsC had fingernail disease. Adjusted models showed that onycholysis and hyperkeratosis were the only type of fingernail disease independently associated with PsA. This association was further confirmed by the forward conditional stepwise regression model (OR, 95% CI for onycholysis: 2.34, 1.79 to 4.27, p < 0.01; for hyperkeratosis: 1.62, 1.12 to 2.66, p = 0.037). ROC analysis showed that, compared to pitting and hyperkeratosis, onycholysis had higher AUC (0.630) and sensitivity (52.6%). The psoriatic fingernail onycholysis and hyperkeratosis hold greater relevance to PsA than pitting. Clinically, psoriatic patients with fingernail onycholysis and hyperkeratosis should be assessed for arthritis. Key Points • Psoriatic fingernail onycholysis and hyperkeratosis, rather than pitting, are significantly associated with PsA • Clinically, psoriatic patients with fingernail onycholysis and hyperkeratosis should be assessed for arthritis.

Dysregulation of miRNA146a versus IRAK1 induces IL-17 persistence in the psoriatic skin lesions.

Psoriasis is a common chronic inflammatory skin disorder with dysregulation of miRNAs. The expression pattern of miR-146a and target gene IRAK1 in lesions and PBMCs of plaque psoriasis remains unclear. In our study, we found the expression of miR-146a was up-regulated both in lesions and PBMCs of psoriatic patients, and positively correlated with IL-17 expression, whereas the target gene IRAK1 expression was expressed differentially in lesions and peripheral blood. Inability of miR-146a inhibiting target gene IRAK1 may contribute to the persistent inflammation in lesions of psoriasis.