Understanding the Relationship Between HS and Inflammatory Arthritis

Image Credit: © dermnetnz.org

Characterized by recurrent painful abscesses, sinus tract formation, and scarring, hidradenitis suppurativa (HS) poses significant challenges not only in dermatologic management but also due to its association with systemic inflammatory conditions, particularly inflammatory arthritis (IA).¹ With this in mind, a recent study aimed to provide dermatologists with an evidence-based understanding of the prevalence and risk factors for IA in patients with HS, facilitating timely identification and management during routine dermatologic evaluations.²

Study Overview

The cross-sectional study conducted at Sunnybrook Health Sciences Centre in Toronto, Ontario, from November 2021 to February 2023 included adult patients with a confirmed diagnosis of HS. Comprehensive data collection included demographic details, disease severity based on the Hurley staging system, treatment regimens, and quality of life assessments using the Dermatology Quality of Life Index (DLQI).

Rheumatologic evaluations were systematically performed, encompassing clinical assessments for musculoskeletal symptoms, inflammatory marker testing, and imaging studies as indicated.

Results

Among the 106 eligible participants, 52 consented to the study. The mean age of participants was 37.4 years, with a majority presenting with moderate HS (Hurley Stage II). The study identified an IA prevalence of 23%, exceeding rates typically observed in associated conditions such as psoriasis and inflammatory bowel disease (IBD).

Key Findings

Risk Factors for IA:

• IBD: Researchers found patients with HS and concurrent IBD had an 8.8-fold increased risk of developing IA.
• Hypertension: The presence of hypertension was associated with a 4.11-fold increased risk of IA, according to the study.
• Family History: Researchers stated a familial history of inflammatory arthritis increased the likelihood by 2.71 times.
• Smoking: Interestingly, they found that smoking was associated with a reduced likelihood of IA (OR: 0.17), suggesting a potential protective effect.

Quality of Life:

• The overall median DLQI score was 10, indicating a significant burden of disease. However, the study found no statistically significant difference was observed in DLQI scores between patients with HS and IA (mean = 11.7) and those without IA (mean = 11.5), suggesting that standard quality of life metrics may not capture the nuanced impacts of IA.

Clinical Implications

Researchers said the findings underscore the importance of screening patients with HS for IA, particularly those with identified risk factors such as IBD and hypertension. They said dermatologists should consider a multidisciplinary approach, referring patients for rheumatological assessment when indicated.

Age and Onset of Symptoms

Notably, the study found patients with IA had a later onset of HS symptoms compared to those without IA, which may inform risk stratification in clinical practice. Increased awareness of these associations may lead to earlier detection and intervention, potentially mitigating the progression of both HS and IA.

Conclusion

This study highlights a substantial prevalence of IA in patients with HS and identifies critical predictors that may assist dermatologists in clinical decision-making. Researchers said understanding the intersection of HS and IA is vital for improving patient management. Incorporating routine screening for IA in dermatologic practice is recommended, particularly in patients with risk factors such as IBD, hypertension, and a family history of inflammatory arthritis. They suggested that enhanced collaboration with rheumatologists may facilitate timely diagnosis and comprehensive management of these patients, ultimately improving their overall quality of life. The study's reliance on a single academic center and its cross-sectional design may introduce selection bias and limit generalizability, warranting further longitudinal studies to explore these associations and develop standardized screening protocols.

References

1. Fimmel S, Zouboulis CC. Comorbidities of hidradenitis suppurativa (acne inversa). Dermatoendocrinol. 2010;2(1):9-16. doi:10.4161/derm.2.1.12490
2. Sy SMT, Eder L, Jerome D, et al. Prevalence and predictors of inflammatory arthritis in hidradenitis suppurativa. Exp Dermatol. 2024;33(10):e15194. doi:10.1111/exd.15194