This non-intervention study will identify the biomarker profiles in hidradenitis suppurativa (HS) and atopic dermatitis (AD) (as a comparator) that would have the most utility in interventional studies evaluating efficacy during therapeutic intervention. Study data will also be used to correlate cellular/molecular changes in blood (cells and serum), and tissue, with clinical/histopathological phenotypes.

This study is an exploratory correlative study in subjects with HS or AD. Blood samples and skin biopsies will be collected from all subjects and used to assess the following: cutaneous and circulating inflammatory biomarkers and IRAK4 target levels in primary samples, correlations between cutaneous and circulating inflammatory biomarkers and disease severity, effects of IRAK4 degradation on IRAK4 levels and downstream inflammatory biomarkers in ex vivo-treated whole blood from patients.

De-identified routine clinical data that is collected will be correlated with the research findings.

Inclusion Criteria:

1. Age 18 or older
2. Active HS or AD disease, diagnosed by PI
3. Patients with mild (HS only), moderate, or severe disease using the HS-PGA or PGA assessment.
4. Must sign an informed consent form (ICF) indicating that he or she understands the purpose of and procedures required for the study, and is willing to participate in the study.

Exclusion Criteria:

1. Patient is currently on a biologic or other immunosuppressive treatment for HS or AD.
2. Use of biologic treatment for HS or AD within 3 months or 5 half-lives, whichever is longer
3. Use of non-biologic immunosuppressive treatment (eg. Cyclosporin) in the last 4 weeks.

Patients with active mild, moderate, or severe HS or active moderate or severe AD disease.