Plain language for living with HS
Sinus tracts and tunnels in hidradenitis suppurativa
A sinus tract in hidradenitis suppurativa is an inflammatory passage beneath the skin, commonly described in patient language as a tunnel. It may connect lesions or surface openings, persist over time, drain repeatedly, and contribute to scarring. Its full extent may not be visible from the surface.
Also called: HS tunnel · skin tunnel
In the HS context
Sinus tract
Sinus tract and tunnel refer to a structural feature beyond one closed nodule.
Why HS sources use both sinus tract and tunnel
Clinical publications have long used sinus tract, while patient-facing sources increasingly use tunnel. Both describe a passage beneath the skin in the HS context. The language points to structure, not something that can be confirmed from one photo or from the fact that a sore has opened.
How a tunnel differs from one draining lesion
A single abscess can open and release fluid without being described as a tunnel. A tunnel is a persistent passage that may connect nearby lesions or openings and may drain again over time. Surface appearance can underestimate what lies underneath, which is why an in-person skin examination matters.
What makes a description useful in the room
Record when the area first appeared, whether drainage returns through the same opening, whether there are several openings, and whether a firm line can be felt between them. Note pain, movement limits, and scarring. These observations support a clearer conversation without trying to label the structure yourself.
How it may be described
- Clues described in sources include repeated drainage, separate openings, firmness, or a cord-like area under the skin.
- The visible opening may show only part of the tract beneath it.
Do not automatically confuse with
Tunneling wound. A wound-care tunnel can occur in other conditions; HS tunnel is anchored to the HS disease context. ↗
Prepare a more precise conversation
Details worth bringing to an appointment
- How many openings are present and do they drain repeatedly?
- Is there a firm or cord-like area between lesions?
Sources
- Hidradenitis suppurativa: Signs and symptomsAmerican Academy of Dermatology · institutionalClinicalGuidance
- Hidradenitis SuppurativaNCBI Bookshelf, StatPearls · peerReviewedPublication
- Hidradenitis Suppurativa (HS)National Institute of Arthritis and Musculoskeletal and Skin Diseases · institutionalClinicalGuidance
Checked: August 9, 2026. Patient-written, checked against the listed sources, and not medically reviewed. Educational information, not personal clinical interpretation.