Can brain scans reveal the hidden toll of hidradenitis suppurativa?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: For Participants With Hidradenitis Suppurativa: * Aged 18 to 45 years. * Diagnosed with hidradenitis suppurativa according to established clinical diagnostic criteria. * Able and willing to comply with the study procedures and follow-up assessments. * Able to provide written informed consent and willing to permit photography of affected skin areas. * No coexisting systemic lupus erythematosus, dermatomyositis, atopic dermatitis, steroid-dependent dermatitis, or other relevant skin diseases. * No use of biologic or small-molecule therapy that may affect hidradenitis suppurativa symptoms within 3 months before enrollment. * Right-handed according to the Edinburgh Handedness Inventory. For Healthy Participants: * Aged 18 to 55 years. * No hidradenitis suppurativa or other chronic skin disease. * No chronic pain disorder. * No major neurological or psychiatric disorder. * Right-handed according to the Edinburgh Handedness Inventory. * Able to provide written informed consent and comply with the study procedures. For the Longitudinal Treatment Cohort: * Meets the eligibility criteria for participants with hidradenitis suppurativa. * Is scheduled to receive biologic or small-molecule therapy for hidradenitis suppurativa as part of routine clinical care, as determined by the treating physician. * Willing and able to complete assessments before treatment and during 3 months of follow-up. Exclusion Criteria: * Participation in another investigational drug study within 1 month before enrollment. * Alcohol or drug abuse or dependence within the previous 3 months. * Current use of medications that may lower the seizure threshold or current use of antidepressant medication. * Previous or current treatment with electroconvulsive therapy, vagus nerve stimulation, or transcranial magnetic stimulation. * Serious cardiac, hepatic, pulmonary, renal, thyroid, hematologic, or other systemic disease; malignant tumor; or another clinically significant abnormality that, in the investigator's judgment, makes participation inappropriate. * Pregnancy or breastfeeding. * Schizophrenia, bipolar disorder, or another major psychiatric disorder. * A neurological condition that may interfere with participation or interpretation of the imaging results, including markedly elevated intracranial pressure, intracranial vascular lesions, impaired consciousness, or inability to cooperate with study procedures. * Any contraindication to magnetic resonance imaging, including intracranial metallic foreign bodies, cardiac pacemakers, incompatible vascular or cardiac implants, or claustrophobia. * Inability to remain still or comply with resting-state functional magnetic resonance imaging procedures. * Unwillingness to allow study data to be collected.