Mild hidradenitis suppurativa (HS) can resemble acne, but doctors characterize this inflammatory skin condition by painful skin nodules, sores, and abscesses.

HS may first present as pimple-like lumps and bumps and is most common in areas with skin-on-skin contact, such as the armpits or groin.

Without treatment, HS can progress, causing pockets of pus beneath the skin, known as abscesses.

Many people who develop abscesses will also experience scarring and the formation of sinus tracts — tunnels of pus extending out into surrounding tissue.

How much pain a person is experiencing, along with the presence of sinus tracts and scarring, helps determine the severity of HS.

This article discusses the symptoms, causes, treatment options, and outlook of mild HS. It also examines how doctors diagnose and grade the condition.

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HS can be mild, moderate, or severe.

Healthcare professionals often diagnose HS using the Hurley system, which categorizes HS into three stages:

  • Stage 1: Abscess formation without tracts or scarring.
  • Stage 2: Recurrent single or multiple abscesses with tracts and scarring.
  • Stage 3: Widespread, interconnected abscesses and sinus tracts, or extensive bodily involvement.

The authors of a 2018 population-based cross-sectional study in the journal PLoS One state that the majority of cases appear to be mild to moderate. However, they also note that there appears to be uncertainty about the true estimation of HS severity distribution.

Early diagnosis is important to help prevent progression. As mild HS can present similarly to other skin conditions, a person may not receive a timely diagnosis.

A 2020 study notes that the average delay in diagnosis is 7 years. In some cases, the delay can be 12 years or longer. By the time people consulted a dermatologist, 93.3% had reached Hurley stage 2 or 3.

The authors also suggest that the Hurley stage definition can overlook disease severity.

Mild HS can start as small, inflamed lumps, pustules, or bumps. While they occur in various places, such as the inner thighs, buttocks, groin, and scalp, HS lesions are most common in or around the armpits.

Abscesses are present in all clinical stages of HS, but mild HS does not typically develop sinus tracts or scarring.

Common symptoms include:

  • itching, burning, sweating, heat, or pain in the area before a lesion appears
  • nodules that grow larger, spread, or merge
  • fluid-filled lumps
  • abscesses
  • open sores and draining abscesses

According to the American Academy of Dermatology Association, risk factors for developing HS in any form include:

  • a family history of HS
  • being between the ages of puberty and 40
  • smoking
  • being of African, Hispanic, or biracial descent
  • carrying excess body weight
  • being female

It is unknown why HS remains mild in some people and progresses in others. However, early intervention, excess body weight, and smoking have associations with disease severity.

A 2020 review notes smoking is an environmental factor with some of the most effect on HS.

The authors note that smoking can increase the areas of the body affected by HS and can also contribute to a weakened treatment response.

Carrying excess body weight may also influence HS severity. A 2019 systematic review in the Journal of Cutaneous Medicine and Surgery found symptoms of HS improved with weight loss and dietary management.

Mild HS may progress to more severe stages without treatment.

Once a doctor or dermatologist diagnoses HS, they will form a treatment plan, which aims to:

  • limit flare-ups
  • heal existing lesions
  • relieve pain
  • prevent HS progression

For mild or uncomplicated HS, a doctor may prescribe topical antibiotics to help resolve inflammation and prevent a secondary infection. Corticosteroid injections directly into lesions may also help with inflammation.

Some people experience faster healing after deroofing — a procedure that removes the skin over an abscess, allowing it to drain.

In addition to clinical treatment, a structured skin care routine may help reduce irritation from harsh over-the-counter washes and antiperspirants.

Even mild HS can be resistant to treatment. When this happens, a healthcare professional may prescribe oral biologic medications, such as adalimumab (Humira), which can provide systemic therapy.

There is no cure for HS, even in its mild form. Early detection improves long-term outlook and increases the chances of successfully managing symptoms.

It may also be possible to stop mild HS from progressing.

Following a treatment plan and making lifestyle changes may even result in the complete resolution of current HS symptoms. However, eliminating a flare-up is not the same as curing HS.

Learn more about whether HS goes away.

There is no singular laboratory test for HS.

To evaluate mild cases, doctors assess a person’s pain alongside:

  • the location and appearance of skin inflammation
  • how frequently symptoms emerge
  • if any circumstances might be causing skin irritation

Testing drainage from an abscess can verify the presence of infection. However, this may only be necessary if a doctor suspects an alternative condition or secondary infection.

Diagnostic imaging can be a part of early evaluation to determine if sinus tracts are present beneath abscesses.

Other grading systems

To determine the stage of HS, doctors may use grading systems other than the Hurley system.

Doctors can also determine mild HS through treatment response time.

The HS Clinical Response (HiSCR) score assesses HS severity by comparing the number of inflammatory skin symptoms before and after treatment.

Rather than assigning severity based on current presentation, HiSCR focuses on how rapidly treatment improves HS.

Mild HS under HiSCR is HS that responds quickly to interventions, though experts often pair this rating with another diagnostic scale, such as the Hurley stages.

Other, more in-depth HS classification systems exist but are primarily for research purposes. These include:

It may be possible to prevent flare-ups of mild HS. Preventive measures include:

  • washing with an antimicrobial wash containing benzoyl peroxide or zinc pyrithione
  • avoiding scrubbing when washing
  • conditioning skin before shaving
  • avoiding waxing
  • opting for laser hair removal
  • limiting sweating and overheating
  • using a mild antiperspirant
  • following established HS treatment plans
  • wearing loose-fitting clothing
  • losing excess body weight
  • quitting smoking
  • limiting sugar and dairy intake
  • trying a plant-based or Mediterranean-style diet

Most people living with HS appear to experience mild or moderate symptoms. In mild HS, abscesses may be present, but no note of significant sinus tracts or scarring.

There is no cure for HS, but lifestyle changes such as weight management and smoking cessation may help resolve mild HS flare-ups.