She was transitioned to certolizumab pegol 200 mg subcutaneous every 14 days with adequate disease control. However, after 12 months of therapy, she developed breakthrough peripheral arthritis with a clinical disease activity psoriatic arthritis score (DAPSA) of 19.5 (corresponding to moderate disease activity), scalp and genital psoriasis (on a total body surface area of 1%), as well as acute left fourth toe and right third toe dactylitis (see Table 1).
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Explore This IssueSeptember 2018
The patient did not meet PsA minimal disease activity criteria (MDA) due to five tender and nine swollen joints, a pain score of 30/100 and a patient global assessment score of 25/100. Given the failure of three tumor necrosis factor (TNF) inhibitors, we switched treatment to 90 mg of subcutaneous ustekinumab every 12 weeks, with loading doses at Days 0 and 28.
We evaluated the patient in our clinic for follow-up six weeks after the initial ustekinumab dose. Her psoriasis and peripheral arthritis had resolved. She demonstrated clinical improvement of the dactylitis and decreased erythema, swelling and tenderness (see Table 2). The patient’s clinical DAPSA was now 13, corresponding to low disease activity, but her PsA activity again did not meet MDA criteria due to four swollen/tender joints of two dactylitic toes, a pain score of 25/100 and a patient global assessment score of 25/100 (see Table 1).
Musculoskeletal ultrasound of her feet revealed hypoechoic collections surrounding the extensor tendons of these dactylitic digits as well as at the interphalangeal joints with Doppler enhancement, consistent with tenosynovitis and synovitis (see Figure 3). We saw no erosions. Radiographs showed slight spurring of the first metatarsophalangeal (MTP) joints and were otherwise unremarkable (see Figure 4). We continued ustekinumab and treated persistent toe dactylitis with local corticosteroid injections.
Should ustekinumab augmented by local corticosteroid injection fail to adequately control disease after the third 90 mg dose (at 16 weeks of treatment), we plan to switch to a biologic with a different mechanism of action.
Psoriatic Arthritis Described
PsA is a complex rheumatologic disease that manifests in multiple individual patterns of musculoskeletal and skin involvement. Its hallmark features include inflammatory musculoskeletal disease in the presence of active or historical psoriasis skin inflammation, or a genetic predisposition to psoriasis through family history in a first- or second-degree relative. Psoriasis prevalence in the U.S. is 2%, and roughly one in three people with psoriasis develop PsA.1