Understanding the purpose of DUPIXENT
DUPIXENT (dupilumab) is a targeted biologic medication designed to treat specific inflammatory conditions. It is a monoclonal antibody that works by inhibiting the signaling of two key proteins, interleukin-4 (IL-4) and interleukin-13 (IL-13). By blocking this specific pathway, DUPIXENT effectively reduces the type of inflammation associated with conditions such as moderate-to-severe atopic dermatitis (eczema), asthma, chronic rhinosinusitis with nasal polyposis, eosinophilic esophagitis, and prurigo nodularis. The mechanism of action is tailored to interrupt the immune response driving these specific diseases, which is different from the inflammatory pathways involved in psoriatic arthritis.
The paradoxical risk of DUPIXENT and psoriatic arthritis
Despite its benefits for other conditions, DUPIXENT is not used to treat psoriatic arthritis. The inflammatory processes that cause PsA differ from those targeted by dupilumab. In PsA, inflammation is primarily driven by other cytokines, particularly interleukin-17 (IL-17) and interleukin-23 (IL-23). There is evidence to suggest that by blocking the IL-4 and IL-13 pathways, DUPIXENT can inadvertently shift the immune balance in some individuals, potentially upregulating the IL-17 pathway. This shift may explain why a small number of patients have reported developing new or worsening psoriatic skin lesions and joint pain resembling PsA while on dupilumab therapy.
Reports indicate that some patients, especially those being treated for atopic dermatitis, have experienced new-onset psoriatic lesions or inflammatory joint symptoms after starting dupilumab. A study published in 2025 noted observations of arthritis and enthesitis resembling PsA in patients initiating dupilumab. While this is considered a rare, or paradoxical, reaction, it highlights the importance of clinical awareness for both dermatologists and rheumatologists. The risk of developing these symptoms needs to be weighed against the significant benefits dupilumab offers for its approved indications.
Comparing DUPIXENT to approved biologics for psoriatic arthritis
To understand why DUPIXENT is not used for PsA, it is helpful to compare its mechanism and indications with biologics that are specifically approved for this condition. These approved treatments target the inflammatory pathways directly linked to PsA.
| Feature | DUPIXENT (dupilumab) | TREMFYA (guselkumab) | SKYRIZI (risankizumab) |
|---|---|---|---|
| Approved Indications | Atopic Dermatitis, Asthma, CRSwNP, EoE, Prurigo Nodularis, CSU | Plaque Psoriasis, Psoriatic Arthritis, Ulcerative Colitis, Crohn's Disease | Plaque Psoriasis, Psoriatic Arthritis, Crohn's Disease |
| Mechanism of Action | Blocks IL-4 and IL-13 signaling | Blocks IL-23 signaling | Blocks IL-23 signaling |
| Primary Target Pathway | Type 2 inflammatory pathway (Th2) | Th17 inflammatory pathway | Th17 inflammatory pathway |
| Known PsA Risk | Potential paradoxical risk of inducing or worsening PsA | No reported paradoxical risk of inducing PsA | No reported paradoxical risk of inducing PsA |
| Dosage Schedule | Varies by condition, often every 2 weeks | Every 8 weeks after initial loading doses | Every 12 weeks after initial loading doses for PsA |
Signs and symptoms to watch for
Patients on DUPIXENT therapy for other conditions should be vigilant for any signs of developing psoriatic arthritis. It is crucial to monitor for new or worsening joint symptoms and report them to a healthcare provider promptly. These symptoms can include:
- Joint pain: Aches and pains in the joints, which may be mild or severe.
- Stiffness: Morning stiffness that lasts for an extended period.
- Swelling: Noticeable swelling in the joints, particularly small joints in the fingers and toes.
- Decreased mobility: Difficulty with walking or performing daily activities due to joint issues.
- Dactylitis: Swelling of an entire finger or toe, sometimes described as a "sausage digit."
- Enthesitis: Pain or tenderness where tendons or ligaments attach to bones, such as the Achilles tendon.
Clinical guidance and next steps
If a patient on DUPIXENT develops new joint pain or skin symptoms, the first step is to consult their prescribing physician or a rheumatologist. The healthcare provider will evaluate the symptoms to determine if they are related to DUPIXENT and if a diagnosis of psoriatic arthritis or another condition is appropriate. In some cases, the physician may decide to discontinue DUPIXENT and switch to an alternative therapy better suited for the patient's overall inflammatory profile. Psoriatic arthritis is a serious condition that can cause irreversible joint damage if left untreated, so an accurate diagnosis and timely treatment are essential.
The American College of Rheumatology is an excellent resource for information on psoriatic arthritis and other rheumatic diseases.
Conclusion
In conclusion, DUPIXENT is not a treatment for psoriatic arthritis and, in a rare but documented number of cases, may contribute to the development or worsening of PsA-like symptoms. Its mechanism of action, while effective for conditions like eczema and asthma, differs from the pathways involved in PsA. For individuals with PsA, there are other targeted biologic treatments, such as IL-23 inhibitors like TREMFYA and SKYRIZI, that are specifically approved and effective for managing the condition. Patients on DUPIXENT must remain aware of the potential for paradoxical symptoms and report any new joint pain or skin issues to their healthcare provider for evaluation.
