Prevalence of Pretreatment Testing Recommended for Patients With Chronic Inflammatory Skin Diseases.

Importance: Laboratory testing for the presence of tuberculosis, hepatitis, and other conditions before starting most systemic immunomodulatory agents is recommended in patients with chronic inflammatory skin diseases (CISD) but current testing patterns in the US are unclear. Objective: To determine the prevalence of pretreatment testing that is recommended for patients with CISD (psoriasis, hidradenitis suppurativa, or atopic dermatitis). Design, Setting, and Participants: This descriptive analysis of US commercial insurance claims databases from December 31, 2002, to December 31, 2020, included adult patients with CISD (psoriasis, hidradenitis suppurativa, or atopic dermatitis) who started an immunomodulatory agent, including methotrexate, tumor necrosis factor α inhibitors, interleukin (IL)-17Ai, ustekinumab, IL-23i, dupilumab, or apremilast. Main Outcomes and Measures: The proportion of patients who underwent the screening tests as suggested by professional societies-including for tuberculosis, hepatitis, and liver function; complete blood cell counts; and lipid panels-were determined within 6 months before and during 2 years after treatment start. Results: A total of 122 308 patients with CISDs (median [IQR] age, 49 [38-58] years; 63 663 [52.1%] male) starting systemic immunomodulatory treatment in the US were included. Treatment for patients with CISDs comprised methotrexate (28 684), tumor necrosis factor α inhibitors (40 965), ustekinumab (12 841), IL-23i (6116), IL-17Ai (9799), dupilumab (7787), or apremilast (16 116). Complete blood cell count was the most common test, performed in 41% (3161/7787) to 69% (19 659/28 684) of individuals before initiation across treatments. Between 11% (889/7787) and 59% (3613/6116) of patients had tuberculosis screening within 6 months before treatment, and 3% (149/4577) to 26% (1559/6097) had updated tests 1 year later. Between 13% (1006/7787) and 41% (16 728/40 965) had hepatitis panels before treatment. Low pretreatment testing levels before apremilast (15% [2331/16 116] to 45% [7253/16 116]) persisted a year into treatment (9% [816/8496] to 36% [2999/8496]) and were similar to dupilumab (11% [850/7787] to 41% [3161/7787] vs 3% [149/4577] to 25% [1160/4577]). Conclusions and Relevance: In this descriptive analysis of patients with CISDs starting systemic immunomodulatory treatment in the US, less than 60% received the recommended pretreatment testing. Additional research is required to understand whether variations in testing affect patient outcomes.

Occurrence of inflammatory bowel disease in patients with chronic inflammatory skin diseases: a cohort study: Classification: Epidemiology.

BACKGROUND: Several studies have linked various chronic inflammatory skin diseases (CISDs) with inflammatory bowel disease (IBD) in a range of data sources with mixed conclusions. OBJECTIVES: We compared the incidence of IBD - ulcerative colitis (UC) and Crohn disease (CD) - in patients with a CISD vs. similar persons without a CISD. METHODS: In this cohort study using nationwide, longitudinal, commercial insurance claims data from the USA, we identified adults and children who were seen by a dermatologist between 2004 and 2020, and diagnosed with either psoriasis, atopic dermatitis, alopecia areata, vitiligo or hidradenitis suppurativa. Comparator patients were identified through risk-set sampling; they were eligible if they were seen by a dermatologist at least twice and not diagnosed with a CISD. Patient follow-up lasted until either IBD diagnosis, death, disenrolment or end of data stream, whichever came first. IBD events, UC or CD, were identified via validated algorithms: hospitalization or diagnosis with endoscopic confirmation. Incidence rates were computed before and after adjustment via propensity-score decile stratification to account for IBD risk factors. Hazard ratios (HR) and 95% confidence intervals (CIs) were estimated to compare the incidence of IBD in CISD vs. non-CISD. RESULTS: We identified patients with atopic dermatitis (n = 123 614), psoriasis (n = 83 049), alopecia areata (n = 18 135), vitiligo (n = 9003) or hidradenitis suppurativa (n = 6806), and comparator patients without a CISD (n = 2 376 120). During a median follow-up time of 718 days, and after applying propensity-score adjustment for IBD risk factors, we observed increased risk of both UC (HRUC 2·30, 95% CI 1·61-3·28) and CD (HRCD 2·70, 1·69-4·32) in patients with hidradenitis suppurativa, an increased risk of CD (HRCD 1·23, 1·03-1·46) but not UC (HRUC 1·01, 0·89-1·14) in psoriasis, and no increased risk of IBD in atopic dermatitis (HRUC 1·02, 0·92-1·12; HRCD 1·08, 0·94-1·23), alopecia areata (HRUC 1·18, 0·89-1·56; HRCD 1·26, 0·86-1·86) or vitiligo (HRUC 1·14, 0·77-1·68; HRCD 1·45, 0·87-2·41). CONCLUSIONS: IBD was increased in patients with hidradenitis suppurativa. CD alone was increased in patients with psoriasis. Neither UC nor CD was increased in patients with atopic dermatitis, alopecia areata or vitiligo. What is already known about this topic? Several studies have linked various chronic inflammatory skin diseases (CISDs) with inflammatory bowel disease (IBD) utilizing a range of data sources, with mixed conclusions. What does this study add? This large-scale, claims-based cohort study expands current knowledge by providing background rates for IBD across multiple CISDs using consistent methods and within a single, nationally representative patient population. We observed a relative increased risk of IBD in patients with hidradenitis suppurativa, but the overall incidence rate difference of IBD was generally low. Crohn disease alone was significantly increased in patients with psoriasis, and neither ulcerative colitis nor Crohn disease was increased in patients with atopic dermatitis, vitiligo or alopecia areata.