<p>Plaque psoriasis often requires a multifaceted approach to treatment. Combination therapies have become a standard of care, especially for recalcitrant disease and for patients with comorbidities such as psoriatic arthritis. The decision on whether to use combination therapy and the choice of therapy should match patient needs.</p>

It is rare that a patient is using only one medication to treat their plaque psoriasis. Even when patients with mild plaque psoriasis are only using topical agents, they are typically given a combination, with a less potent agent for areas of sensitive skin and a more potent one for areas with thicker plaques. Topical therapy may also be added to phototherapy, an oral medication, or a biologic treatment.

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Even though drugs for plaque psoriasis have significantly improved over the years, there is still not a single drug that offers a complete cure. For instance, for flare-ups while a patient is on oral or biologic therapies, a topical therapy might need to be added to get it under control. Moreover, certain areas of the body also tend to be harder to treat, and areas such as the scalp, hands, feet, and genitals may be slower to heal, despite using the best systemic treatments. In these cases, we also need to add a topical agent to help manage the disease. Another scenario is adding a concomitant oral agent to an existing biologic treatment. I often add methotrexate for difficult-to-treat skin disease or psoriatic arthritis that is not completely controlled by a biologic agent. I may also add one of the more modern oral agents, such as apremilast or deucravacitinib.

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A major driver for using combination therapies is recalcitrant disease. If a patient’s plaque psoriasis is not fully controlled with one therapy alone, we need to add another agent to achieve improved results. In my practice, the other major driver is the presence of comorbidities, most commonly psoriatic arthritis. Often, psoriatic arthritis does not respond well to skin-directed therapies, so I add another agent to control the joint disease. We need to talk to our patients to figure out which adjunctive treatment is going to work best for them, and this includes considering the comorbidities they might have. Another challenging consideration is insurance coverage. An insurer might not be willing to cover a biologic agent in combination with an oral agent. In those cases, we may need to lean on combination treatment with methotrexate, phototherapy, or topical agents.

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Using multiple treatments can make it more challenging for patients to adhere to therapy, but sometimes they appreciate having another treatment they can use when their background therapy is not working. We also need to consider the side effects of the individual medications. We mainly worry about compounding the risk of infection when combining 2 systemic agents. Sometimes, when using combination therapies, we are able to use lower doses or reduce the frequency of treatment to decrease the risk of side effects.