Treating psoriasis (PsO) with biologics may be associated with a lower risk of developing psoriatic arthritis (PsA), according to study results published in Annals of the Rheumatic Diseases.

Several risk factors have been described in the literature with regard to progression from PsO to PsA, including extension of skin disease, obesity, and subclinical enthesitis. Biologic therapies, including tumor necrosis factor α (TNF- α) inhibitors, interleukin (IL)-12/IL-23, IL-17, and IL-23, have been shown to be effective for PsO treatment. However, the use of these treatments in the development of PsA is still unclear. 

To evaluate the incidence of PsA in patients with PsO receiving various types of treatments, including biologic disease-modifying antirheumatic drugs (bDMARDs), topical medications, or conventional DMARDs (cDMARDs), the researchers included data from a large university hospital-based health care management organization. Patients with PsO, diagnosed by a dermatologist without musculoskeletal symptoms, and without a PsA diagnosis between January 2000 and December 2018 were eligible for the study. A PsA diagnosis was confirmed by a rheumatologist and/or the fulfillment of the classification criteria for PsA (CASPAR) after 1 month of study entry.

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In the primary analysis, incident cases of PsA were attributed to a treatment group if the PsA developed during the administration of the treatment. In the secondary analysis, the PsA incidence was considered related to either cDMARDs or bDMARDs if the patient had received the biologic for at least 6 months.

A total of 1719 patients with PsO who contributed a total of 14,721 patient-years were included in the primary analysis. Overall, 1387 (81%) patients received treatment with topical medications, 229 (13%) with cDMARDs, and 103 (6%) with bDMARDs. Patients who received treatment with biologics were significantly younger and men.

During follow-up, 239 patients (13.9%) developed PsA, of whom 6 received treatment with cDMARDs and 2 with bDMARDs. Among patients who received cDMARD treatment, 5 received only methotrexate and 1 received cyclosporine for 3 months after 4 months of methotrexate, 13 months prior to initiating cyclosporine. Two patients developed PsA while receiving treatment with bDMARDs (1 secukinumab and 1 ustekinumab).

The global incidence of PsA development was 1.6 per 100 patient-years.

In the primary analysis, the risk for PsA in patients with PsO who received bDMARDs was significantly lower than that of patients who received topical treatment (incidence rate ratio [IRR], 0.26; 95% CI, 0.03-0.94; P =.0111), but not those who received cDMARDs (IRR, 0.35; 95% CI, 0.035-1.96; P =.1007). Results of the secondary analysis demonstrated similar results for patients who received bDMARDs compared with those who received topical treatment (IRR, 0.34; 95% CI, 0.07- 0.99; P =.0158).

The researchers noted that although their study was a single center, retrospective chart review of electronic medical records, it provided reliable incidence and prevalence data. Other study limitations included the lack of adjusting for confounding factors, such as severity of skin involvement; the possibility of protopathic bias if the biologics were prescribed because of the presence of early PsA that were not notified or registered; and the small number of patients who received treatment with cDMARDs and bDMARDs.

“Preventing development of PsA could be another factor suggesting the use of biologics early on in the treatment of the skin in patients with PsO at increased risk of developing PsA,” the study authors concluded.

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.


Felquer MLA, LoGiudice Lo, Galimberti ML, Rosa J, Mazzuoccolo. Treating the skin with biologics in patients with psoriasis decreases the incidence of psoriatic arthritis. Ann Rheum Dis. Published online July 19, 2021. doi:10.1136/annrheumdis-2021-220865