Anna Figueiredo, MD, declared at the virtual annual meeting of the American Academy of Dermatology.
The surprise about this finding from a large retrospective case-control study stems from the fact that the elevated risk for hypothyroidism didn’t also extend to younger women with hidradenitis suppurativa (HS) nor to patients older than 40 years of either gender, explained Dr. Figueiredo of the department of dermatology at Northwestern University, Chicago.
She presented a retrospective case-control study based on information extracted from a medical records database of more than 8 million Midwestern adults. Among nearly 141,000 dermatology patients with follow-up in the database for at least 1 year, there were 405 HS patients aged 18-40 years and 327 aged 41-89.
In an age-matched comparison with the dermatology patients without HS, the younger HS cohort was at a significant 1.52-fold increased risk for comorbid hypothyroidism. Upon further stratification by sex, only the younger men with HS were at increased risk. Those patients were at 3.95-fold greater risk for having a diagnosis of hypothyroidism than were age-matched younger male dermatology patients.
Both younger and older HS patients were at numerically increased risk for being diagnosed with hyperthyroidism; however, this difference didn’t approach statistical significance because there were so few cases: a total of just eight in the HS population across the full age spectrum.
Hidradenitis suppurativa is a chronic inflammatory disease with an estimated prevalence of up to 4% in the United States. Growing evidence suggests it is an immune-mediated disorder because the tumor necrosis factor inhibitor adalimumab (Humira) has been approved for treatment of HS.
Thyroid disease is also often autoimmune-mediated, but its relationship with HS hasn’t been extensively examined. A recent meta-analysis of five case-control studies concluded that HS was associated with a 1.36-fold increased risk of thyroid disease; however, the Nepalese investigators didn’t distinguish between hypo- and hyperthyroidism (J Am Acad Dermatol. 2020 Feb;82[2]:491-3).
Dr. Figueiredo reported having no financial conflicts regarding her study, which was without commercial support.