What is the cause of worsening joint pain and redness in a 33-year-old female patient with psoriatic arthritis on methotrexate (a disease-modifying antirheumatic drug)?

From the Guidelines

The patient's worsening joint pain and redness may be due to inadequate response to methotrexate or methotrexate failure 1.

Possible Causes

• Inadequate dose of methotrexate
• Inadequate duration of methotrexate therapy
• Presence of poor prognostic factors such as structural damage, high erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP), dactylitis, or nail involvement

Next Steps

A possible next step could be to increase the methotrexate dose to 25mg weekly, if she is currently on a lower dose, and add a low-dose oral corticosteroid, such as prednisone 5-10mg daily, for a short period of 1-2 weeks to control the flare 1.

Additional Measures

Additionally, a non-steroidal anti-inflammatory drug (NSAID) like ibuprofen 400-600mg three times daily or naproxen 250-500mg twice daily could be added for symptomatic relief 1.

Monitoring and Adjustment

It is also essential to assess for any signs of infection or other complications that may require urgent attention and close monitoring of the patient's condition and adjustment of the treatment plan as needed is crucial 1.

Alternative Therapies

If the patient has an inadequate response to methotrexate, biologic disease-modifying antirheumatic drugs (bDMARDs) such as tumor necrosis factor (TNF) inhibitors, interleukin (IL)-17 inhibitors, or IL-12/23 inhibitors may be considered 1.

From the FDA Drug Label

The mechanism of action in rheumatoid arthritis is unknown; it may affect immune function. Although methotrexate clearly ameliorates symptoms of inflammation (pain, swelling, stiffness), there is no evidence that it induces remission of rheumatoid arthritis nor has a beneficial effect been demonstrated on bone erosions and other radiologic changes which result in impaired joint use, functional disability, and deformity

The cause of worsening joint pain and redness in a 33-year-old female patient with psoriatic arthritis on methotrexate is unknown. Methotrexate may affect immune function, but its exact mechanism of action in rheumatoid arthritis and psoriatic arthritis is not well understood 2.

From the Research

Possible Causes of Worsening Joint Pain and Redness

• Methotrexate intoxication due to deteriorating renal function 3
• Methotrexate toxicity, which can be increased in patients with poor renal function 4, 5
• Inadequate response or intolerability to oral methotrexate, which may require a switch to subcutaneous methotrexate 6, 7
• Other factors such as co-medication, impaired kidney function, or conditions predisposing to methotrexate intoxication 3, 4, 5

Monitoring and Prevention

• Frequent monitoring of blood count and renal and liver function tests to detect early deterioration 3
• Awareness of conditions and factors predisposing to methotrexate intoxication, such as impaired kidney function and co-medication 3, 4, 5
• Consideration of switching to subcutaneous methotrexate if oral methotrexate treatment fails due to intolerability or inadequate response 6, 7

Treatment Optimization

• High initial dose of methotrexate followed by rapid titration to improve response 7
• Continuing treatment with oral methotrexate for at least 6 months to achieve an accurate assessment of treatment efficacy 7
• Maintaining methotrexate dosage and route of administration when transitioning from oral to subcutaneous delivery or adding another RA treatment 7