Researchers suggested there is a dose relationship between smoking exposure and cutaneous manifestations in systemic lupus erythematosus, which highlights the importance of smoking cessation to improve outcomes, according to a presentation at the American College of Rheumatology/Association of Rheumatology Professionals annual meeting.
“Any smoking exposure was an independent risk factor for nearly all cutaneous manifestations of SLE, whereas high smoking exposure and patients of color had significantly increased risk of chronic cutaneous manifestations and persistent skin damage,” Trevor McKown, MD, of University of Wisconsin School of Medicine and Public Health, and colleagues wrote in the study abstract.
Researchers conducted an electronic health records search to identify patients meeting ACR 1997 or SLICC 2012 classification criteria and with at least one ambulatory rheumatology encounter with an SLE ICD-9 or -10 code from 2003 to 2016.
Six hundred thirty-two patients with SLE were identified. ACR or SLICC cutaneous criteria and SLICC Damage Index (DI) cutaneous criteria were the primary outcomes of the study.
Smoking exposure was defined as low (< 5 pack-years), medium (5 to 10 pack-years) and high (>10 pack years) compared with nonsmokers.
Mean patient age was 42 ± 14 years, with 91% of patients being female and 82% white. Forty percent of patients reported ever smoking in their life.
When compared with nonsmokers, those with low smoking exposure were nine times more likely to develop any mucocutaneous manifestations (OR = 9.0; 1.2-67.7), four times more likely to meet an SLICC cutaneous criteria (OR = 3.7; 1.3-10.6) and twice as likely to meet ACR cutaneous criteria (OR = 2.0; 1.0-3.8). Medium smokers were twice as likely to meet acute cutaneous SLICC criteria (OR = 2.3; 1.1-5.1) compared with nonsmokers. Patients with high smoking exposure had double the odds of discoid lupus (OR = 2.1; 1.1-4.1).
Researchers also identified linear pack-year trends in chronic cutaneous SLICC criteria (OR = 2.2; 1.2-4.2) and SLICC DI cutaneous criteria (OR = 4.2; 0.9-9.2) that met significance in high smoking exposure.
Additionally, they identified an increased risk for alopecia, discoid lupus, chronic cutaneous lupus and DI skin damage in patients of color.
Limitations of the study included a smaller sample size and only 18% patients of color. – by Abigail Sutton
Ezeh N, et al. Smoking exposure in pack-years predicts cutaneous manifestations of lupus. Presented at: American College of Rheumatology/Association of Rheumatology Professionals annual meeting; Nov. 9-13, 2019; Atlanta.
Disclosures: McKown reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.