NEW YORK (Reuters Health)—Patients with hidradenitis suppurativa face an increased risk of developing inflammatory arthritis, according to findings from a claims database.
“We observed increased risks of developing ankylosing spondylitis, psoriatic arthritis and rheumatoid arthritis (RA) among patients with hidradenitis suppurativa when compared with those without hidradenitis suppurativa,” says Maria C. Schneeweiss, MD, of Brigham and Women’s Hospital, Harvard Medical School, Boston.
“This suggests a possible systematic association between hidradenitis suppurativa and subsequent newly diagnosed inflammatory joint disease,” she tells Reuters Health by email.
Hidradenitis suppurativa, a condition in which small, painful lumps form under the skin, has been associated with a high prevalence of spondyloarthritis, but it remains unclear whether people with hidradenitis suppurativa have an increased risk of developing inflammatory arthritis.
For their study, published in JAMA Dermatology, Dr. Schneeweiss and her colleagues used longitudinal claims data from commercially insured patients. They matched more than 70,000 patients with hidradenitis suppurativa and twice as many without hidradenitis suppurativa. Median follow-up was 1.5 years (maximum follow up: 11 years).1
Compared with patients without hidradenitis suppurativa, patients with hidradenitis suppurativa had a 65% higher risk of developing ankylosing spondylitis (0.60 vs. 0.36 per 1,000), a 44% higher risk of developing psoriatic arthritis (0.84 vs. 0.58 per 1,000) and a 16% higher risk of developing RA (4.54 vs. 3.86 per 1,000)—all significant risk increases.
The risks of other spondyloarthritides were not raised.
“Although the data support a systematic association between hidradenitis suppurativa and subsequent newly diagnosed inflammatory joint disease, the low incremental risk is reassuring,” Dr. Schneeweiss says.
“Given the high burden of disease associated with both hidradenitis suppurativa and inflammatory arthritis, physicians treating patients with hidradenitis suppurativa should be aware of symptoms suggestive of inflammatory arthritis, including morning stiffness [and] joint pain/swelling, and consider referral to a rheumatologist as appropriate,” she says.
Dr. Schneeweiss adds, “Hidradenitis suppurativa with comorbid inflammatory arthritis may benefit from different approaches to therapy that would address both components of disease [e.g., choosing a TNF-inhibitor, which would act as an effective hidradenitis suppurativa treatment, as well as a treatment intervention for concurrent spondylarthritis].”
The study was partially funded by a Pfizer fellowship for dermatology-pharmacoepidemiology research.
- Schneeweiss MC, Kim SC, Schneeweiss S, et al. Risk of inflammatory arthritis after a new diagnosis of hidradenitis suppurativa. JAMA Dermatol. 2020 Jan 22. [Epub ahead of print]