Original Research
Disease Burden and Treatment Adherence in Psoriasis Patients
Psoriasis can have a large impact on a patient’s quality of life, yet adherence to psoriasis treatment often is poor.
We have already come a long way from thinking that psoriasis is merely a cutaneous disease caused by a defect in cellular replication; we now recognize that psoriasis is a systemic inflammatory process that has broad health implications. This association is manifested by comorbidities such as the occurrence of the metabolic syndrome and an increased risk for myocardial infarction. An increased incidence of chronic obstructive pulmonary disease also has been demonstrated in patients with psoriasis, especially those who smoke. Unfortunately, recent publications have highlighted investigative work that expands the scope of psoriatic comorbidity into new realms.
Li and colleagues (Ann Rheum Dis. 2013;72:1200-1205) performed a retrospective analysis of 174,476 women enrolled in several large national health studies. They found an increased risk for incident Crohn disease (relative risk [RR], 4.00; 95% confidence interval [CI], 1.72-9.27) among women with psoriasis. This increased risk rose (RR, 6.43; 95% CI, 2.04-20.32) if both psoriasis and psoriatic arthritis were present. Although the risk for those who already have Crohn disease to develop psoriasis has been previously noted, this study provides the first convincing clinical evidence that the converse association also is true, which is is not totally surprising when one considers common genetic and aberrant cytokine profiles between Crohn disease and psoriasis to suggest an overlap in pathogenic mechanisms.
Perhaps more ominous was the recently published work of Wan and associates (BMJ. 2013;347:f5961). In this massive retrospective analysis utilizing detailed British electronic medical records, 136,529 patients with mild psoriasis and 7354 patients with severe psoriasis based on treatment patterns were matched to 689,702 unaffected patients. The investigators found a clear increased risk for chronic renal disease (RR, 1.93; 95% CI, 1.79-2.08) among those with severe psoriasis. The risk was higher in younger patients; for example, among those aged 30 years, the RR rose to 3.82 (95% CI, 3.15-4.64). The risk for developing renal disease was independent of well-known predisposing factors, such as diabetes mellitus and hypertension. The association between severe psoriasis and renal disease also appeared to be independent of medications administered for psoriasis (eg, cyclosporine).
Also alarming was a recently published systematic review and meta-analysis of 1080 publications concerning the potential association between psoriasis and cancer (J Eur Acad Dermatol Venereol. 2013;27[suppl 3]:36-46). Pouplard et al found that there may be an increased risk for the following solid cancers in psoriasis patients: respiratory tract cancer (RR, 1.52; 95% CI, 1.35-1.71), upper aerodigestive tract cancer (RR, 3.05; 95% CI, 1.74-5.32), urinary tract cancer (RR, 1.31; 95% CI, 1.11-1.55), and liver cancer (RR, 1.90; 95% CI, 1.48-2.44). To the authors, the association seemed particularly strong with these neoplasms, which are associated with excessive alcohol ingestion and smoking.
What’s the issue?
Why might these comorbidities occur? Perhaps chronic inflammation due to abnormal cytokine production and/or deviant immune defenses may promote these new (or better documented) psoriatic comorbidities. Why are they of importance to dermatologists? Because we are the primary source of care for patients with psoriasis, especially those with severe disease. We cannot stop our historical reviews and physical examination with the skin and joints; rather, we must consider the whole patient. We probably should at least perform a comprehensive history at each visit, being carefully attune to any new concerns that suggest gastrointestinal, pulmonary, and renal disease or internal neoplasia, which places an extra (and perhaps unwanted) burden of care on the dermatologist. However, the way I see it is that our role in early detection of an ever-expanding list of serious psoriatic comorbidities may be crucial to the ultimate long-term health of our patients. Are you ready to accept that intensified and enhanced medical responsibility?
