Hidradenitis Suppurativa Symptoms: What HS Looks Like

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Early Warning Signs of Hidradenitis Suppurativa

Illustrated guide to the 7 early warning signs of HS, with diagnostic criteria and guidance on when to see a dermatologist.

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Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that causes painful lumps, abscesses, and tunnels to form deep in the skin. It affects approximately 1–4% of the population, yet it takes an average of 7 to 10 years to receive a correct diagnosis, largely because its symptoms are so often mistaken for boils, cysts, or folliculitis.

Understanding what HS actually looks and feels like is the first step toward getting the right care. This guide walks you through every major symptom, explains why they happen, and helps you understand when it is time to see a specialist.

This page is for educational purposes only. If you suspect you have HS, please consult a board-certified dermatologist for a proper diagnosis.

The Core Symptoms of HS

Painful Nodules

Deep, painful lumps that feel like hard peas or marbles under the skin. They can be intensely tender and may persist for weeks before rupturing or resolving.

Abscesses

Pus-filled cavities that form when nodules become infected. They are extremely painful, warm to the touch, and may drain spontaneously, producing foul-smelling discharge.

Sinus Tracts (Tunnels)

Channels that form under the skin connecting multiple abscesses. These tunnels are a hallmark of moderate-to-severe HS and are responsible for chronic drainage and scarring.

Scarring

Repeated flares cause permanent scarring, including rope-like bands of scar tissue (fibrosis) and "tombstone" comedones, open blackheads that mark healed tunnels.

What makes HS distinct from ordinary skin infections is its recurrence. The same areas flare repeatedly, often in a predictable pattern tied to hormonal cycles, stress, or friction. Over time, the repeated inflammation causes progressive scarring that can restrict movement and significantly impact quality of life.

Where Does HS Appear?

HS preferentially affects areas where skin folds create friction and where apocrine sweat glands are concentrated. The table below shows the most common affected areas and their typical characteristics.

Body Area	Frequency	Notes
Armpits (axillae)	Most common	Often the first site affected
Groin and inner thighs	Very common	Can cause significant mobility issues
Buttocks and perianal area	Common	Associated with more severe disease
Under the breasts (inframammary)	Common in women	Worsened by bra friction
Waistband / belt line	Moderate	Friction-driven
Nape of neck / scalp	Less common	Often misdiagnosed as folliculitis

How Symptoms Progress Over Time

HS is classified into three stages using the Hurley Staging System. Understanding your stage helps you and your doctor choose the most appropriate treatment.

Stage I. Mild

Single or multiple abscesses without sinus tracts or significant scarring. Lesions heal between flares. This stage is most responsive to topical and oral treatments.

Stage II. Moderate

Recurrent abscesses with sinus tract formation and scarring. Multiple affected areas with some distance between lesions. Systemic treatments (biologics, antibiotics) are typically needed.

Stage III. Severe

Diffuse involvement across entire regions with multiple interconnected sinus tracts and extensive scarring. Surgical intervention is often required alongside systemic therapy.

For a detailed breakdown of each stage with treatment options, see our complete guide to HS stages.

When to See a Doctor

You should seek medical evaluation if you experience any of the following:

✓Painful lumps in skin-fold areas that recur in the same location
✓Lumps that drain pus or fluid and leave scars
✓Multiple simultaneous lesions in different areas
✓Lesions that have been present for more than 3 months
✓Significant pain that interferes with daily activities
✓Fever, chills, or spreading redness around a lesion (seek urgent care)

Request a referral to a board-certified dermatologist with HS experience. Use our HS Specialist Finder to locate providers near you.

Frequently Asked Questions

What are the first signs of hidradenitis suppurativa?

The earliest signs of HS are typically small, painful pea-sized lumps under the skin in areas where skin rubs together, most commonly the armpits, groin, buttocks, and under the breasts. These bumps may feel like pimples or boils and can be tender to the touch. They often appear before age 40, with many patients noticing their first lesion in their teens or twenties.

How do I know if I have HS or just a boil?

Unlike a typical boil, HS lesions recur in the same areas, often form tunnels (sinus tracts) under the skin, and appear in multiple locations simultaneously. HS is also associated with scarring over time. If you have recurring painful lumps in skin-fold areas that keep coming back, see a dermatologist. HS is frequently misdiagnosed as recurring boils or folliculitis.

Does HS smell bad?

Yes, HS lesions can produce a distinctive odor when they rupture and drain. This is caused by bacteria in the wound and the breakdown of skin tissue. The odor is not a sign of poor hygiene, it is a medical symptom of the condition. Proper wound care, antibacterial cleansers, and in some cases antibiotics can help manage odor.

Is HS contagious?

No. HS is not contagious and cannot be spread through skin contact, sharing towels, or any other form of transmission. It is an inflammatory condition related to the immune system and hair follicles, not an infection that can be passed from person to person.

What triggers HS symptoms to get worse?

Common HS triggers include friction from tight clothing, sweating, heat and humidity, hormonal fluctuations (especially around menstruation), smoking, stress, and certain foods (particularly dairy and high-glycemic foods in some patients). Identifying and managing your personal triggers is a key part of living with HS.

Can HS symptoms appear anywhere on the body?

HS most commonly affects areas where skin touches skin or where there is friction, armpits, groin, inner thighs, buttocks, and under the breasts. Less commonly, it can affect the nape of the neck, scalp, waistband area, and behind the ears. The face is rarely affected.