Psoriasis and Migraine: What's the Connection?

COMMENTARY

Graeme M. Lipper, MD

Increased Risk of Migraine in Patients With Psoriasis: A Danish Nationwide Cohort Study.

Egeberg A, Mallbris L, Hilmar Gislason G, Skov L, Riis Hansen P
J Am Acad Dermatol. 2015;73:829-835 

Psoriasis and Migraine

Psoriasis vulgaris (PV) and psoriatic arthritis (PsA) are T-lymphocyte-mediated autoimmune disorders characterized by chronic, organ-specific (skin, joints) and systemic inflammation. This latter fact about psoriasis-that it is associated with multiple medical comorbid conditions-has been bolstered by myriad recent studies linking psoriasis with cardiovascular disease (stroke, ischemic heart disease, congestive heart failure, hypertension) and metabolic disorders (dyslipidemia, obesity, insulin resistance, and type 2 diabetes).^[1-3]

Migraine is a common neurovascular condition characterized by intermittent headaches with or without auras. Some of the same proinflammatory cytokines linked to psoriasis (eg, tumor necrosis factor-alpha) may also contribute to the vasospasm, meningeal inflammation, and pain pathway hypersensitivity found in migraine sufferers.^[4] Furthermore, persons with migraine—like those with psoriasis—have an elevated risk for such cardiovascular diseases as stroke.^[5] But are migraines more prevalent in patients with psoriasis than in those without psoriatic skin or joint diseases?

Study Summary

To address this intriguing question, Egeberg and colleagues used the Danish National Patient Register to gather data from Danish adults (age >18 years) over a 14-year period (n = 5,379,859). This deep pool of data yielded 53,006 cases of mild PV, 6831 cases of severe PV, and 6243 cases of psoriatic arthritis. A comparison of migraine incidence in these three groups compared with the control population generated the following observations:

• Fully adjusted incidence rate ratios for migraine in patients with mild PV, severe PV, and PsA were 1.37, 1.55, and 1.92, respectively;
• The increased risk for migraine seen in patients with psoriasis was severity-dependent (ie, the risk was greater in severe vs mild psoriasis); and
• The psoriasis-associated increased risk was the same for men and women (ie, not sex specific).

Viewpoint

This large Danish study yielded some tantalizing observations. Individuals with psoriasis in this mostly white population were at higher risk of developing migraines, and this risk was proportional to the severity of their skin disease. Furthermore, patients with psoriatic arthritis had the highest migraine risk, suggesting that the level of systemic inflammation may be important.

But what conclusions can we draw from this statistical link? As Egeberg and colleagues pointed out, association does not establish causality. Although they controlled for comorbid conditions, socioeconomic status, hospitalization, and other confounding variables, it is still possible that some of the migraine cases reported in patients with severe PV or PsA were triggered or exacerbated by medications used to treat the skin or joint disease (eg, methotrexate or cyclosporine). Nevertheless, because both migraines and psoriasis are associated with cardiovascular disease and proinflammatory cytokines, a deeper connection needs to be investigated. For instance, does treatment of psoriasis reduce the severity and frequency of migraine headaches? If so, would this reduction be seen only with tumor necrosis factor-alpha-blocking agents, or would topical agents or phototherapy also improve the migraines?

Answering these questions will lead to a better understanding of both psoriasis and migraines and may even lead to novel treatments for both of these common, potentially crippling diseases.