Exploration of Brain Functional Networks in Patients With Hidradenitis Suppurativa Using fMRI

The goal of this observational study is to learn whether adults with hidradenitis suppurativa (HS) have changes in resting brain activity and how these changes are related to disease severity, pain, sleep, mood, and quality of life. The study will also examine whether brain activity changes after patients receive biologic or small-molecule treatment as part of their regular medical care. The main questions it aims to answer are: * Are resting brain activity patterns different between people with HS and healthy participants? * Are these brain activity patterns related to HS severity, pain, sleep problems, anxiety, depression, and quality of life? * Do brain activity patterns change after 3 months of routine treatment, and are these changes related to improvement in HS symptoms? Researchers will compare participants with HS with healthy participants of similar age and sex. A subgroup of participants with HS who receive biologic or small-molecule treatment as part of routine clinical care will also be assessed before and after treatment. Participants may: * Complete assessments of HS severity, pain, sleep, mood, and quality of life * Undergo resting-state functional magnetic resonance imaging * Undergo skin ultrasound and routine laboratory testing * Allow photographs of affected skin areas to be taken * Return for follow-up assessments for up to 3 months