To the left of the image, a Black woman poses looking into the camera while lifting up her shirt, showing scars from her hidradenitis suppurativa (HS) flares under her right and left breasts. To her right reads a headline: "HS TRUTH: HS runs deep. What you see is only part of the burden." Below the headline is a tag with the patient's name which reads "Jasmine S, real HS patient."
To the left of the image, a Black woman poses looking into the camera while lifting up her shirt, showing scars from her hidradenitis suppurativa (HS) flares under her right and left breasts. To her right reads a headline: "HS TRUTH: HS runs deep. What you see is only part of the burden." Below the headline is a tag with the patient's name which reads "Jasmine S, real HS patient."
Jasmine S, real HS patient.

More than skin deep

HS is a chronic inflammatory condition caused by systemic inflammation.1–3

See how HS is driven by the immune pathways, causing an inflammatory cascade.1–3

A scientific image of the immune pathway with a green play button layered on top
 

HS is more than skin deep. It’s driven by chronic inflammation.

HS involves multiple cell types and cytokines, several of which are mediated by JAK-STAT signaling.1–3

Illustration showing a blocked and swollen hair follicle under the skin, depicting how it becomes occluded and then ruptures, releasing debris into the dermis

Inflammation begins under the skin when a hair follicle becomes occluded and dilated, then ruptures, releasing cellular debris into the dermis.4

Illustration of immune cells activating inflammatory pathways that drive a harmful cascade in HS, leading to nodules, abscesses, and tunnels in the skin

This triggers key inflammatory pathways to become activated. Rather than healing the tissue, a complex immune response becomes pathologic in HS, setting off a harmful inflammatory cascade that can lead to the formation of additional nodules, abscesses, and draining tunnels in the skin.2

Illustration showing cytokines sending signals to various cell types including immune cells, keratinocytes, fibroblasts, and endothelial cells depicting their role in directing the immune response in HS

Many different cytokines are involved in HS, directing the immune response by sending signals inside various cell types, including immune cells, keratinocytes, fibroblasts, and endothelial cells.1,2

Illustration showing that several cytokines rely on the JAK‑STAT pathway to direct an immune response

Several cytokines rely on the JAK-STAT pathway to direct an immune response.5

Illustration showing how JAK enzymes help communicate between cytokines and the cell nucleus, amplifying inflammatory signaling in HS

The JAK enzymes are key for communication between cytokines and the cell nucleus. Their signaling amplifies the inflammatory immune response. JAK1 is activated by a wide range of cytokines, which makes it an important factor in HS pathophysiology.5,6

Illustration showing the JAK‑STAT pathway and the role of JAK1 in mediating the inflammatory cascade in HS

Understanding the role of the JAK-STAT pathway, including JAK1, in mediating the inflammatory cascade of HS is important.5,6

Icon showing a green petri dish and three arrows circling it

For people with HS, this immune signaling becomes an overpowering inflammatory cascade that is a main driver of HS symptoms.2,6

“Staying optimistic on my side has become much easier with all of these new therapies that we now have available.”

—Dermatologist, Tennessee

Connect with us

HS, hidradenitis suppurativa; JAK1, Janus kinase 1; JAK-STAT, Janus kinase-signal transducer and activator of transcription.

REFERENCES: 1. Sabat R, Alavi A, Wolk K, et al. Hidradenitis suppurativa. Lancet. 2025;405(10476):420-438. doi:10.1016/S0140-6736(24)02475-9 2. Wolk K, Join-Lambert O, Sabat R. Aetiology and pathogenesis of hidradenitis suppurativa. Br J Dermatol. 2020;183(6):999-1010. doi:10.1111/bjd.19556 3. Gadina M, Johnson C, Schwartz D, et al. Translational and clinical advances in JAK-STAT biology: The present and future of jakinibs. J Leukoc Biol. 2018;104(3):499-514. doi:10.1002/JLB.5RI0218-084R 4. Saunte DML, Jemec GBE. Hidradenitis suppurativa: advances in diagnosis and treatment. JAMA.
2017;318(20):2019-2032. doi:10.1001/jama.2017.16691 5. Rumberger BE, Boarder EL, Owens SL, Howell MD. Transcriptomic analysis of hidradenitis suppurativa skin suggests roles for multiple inflammatory pathways in disease pathogenesis. Inflamm Res. 2020;69(10):967-973. doi:10.1007/s00011-020-01381-7 6. Krueger JG, Frew J, Jemec GBE, et al. Hidradenitis suppurativa: new insights into disease mechanisms and an evolving treatment landscape. Br J Dermatol. 2024;190(2):149-162. doi:10.1093/bjd/ljad345