What is Hidradenitis Suppurativa?

Written by Dr. rer. nat. Dennis Alexander Kwiatkowski

In short

Hidradenitis suppurativa is the term commonly used in the medical literature for the condition that is often called Acne Inversa in German-speaking countries. The abbreviation HS refers to the same condition.

HS is a chronic inflammatory skin disease. It can cause painful nodules, abscesses, weeping areas, sinus tracts and scars. Typical sites include the armpits, groin, genital and perianal region, buttocks or skin folds under the breasts.

The most important points at a glance

• HS is not contagious and is not caused by poor hygiene.
• The condition is not defined by a single symptom but by a pattern.
• This pattern links typical lesions, typical body sites and recurrence.
• Other causes can look similar. A medical examination remains important.

Why are there several names?

The names emphasise different aspects. “Acne Inversa” is historically widespread but can be misleading, because HS is not simply ordinary acne in a different location. “Hidradenitis suppurativa” is internationally established, although for many patients it can sound unfamiliar at first.

For conversations in practice, the important point is: when HS, Hidradenitis suppurativa or Acne Inversa appears in reports, studies or patient information, it generally refers to the same condition.

How can HS look?

HS does not always begin with the full picture of sinus tracts and scars. Early symptoms can resemble isolated deep nodules, “boils” or recurrent ingrown hairs. Over time, a pattern may become apparent:

• Nodules recur at the same site or at several typical sites.
• The lesions are deep, tender to pressure or severely painful.
• Areas may open up and discharge fluid.
• After inflammation, scars, hardened cords or sinus tracts can remain.

This pattern is more important than a single photo or a single acute day. It also explains why a healed area at the time of an appointment does not mean that the history is unimportant.

Which features belong in the medical assessment

The German guideline describes the diagnosis primarily as a clinical assessment. Examination and history bring together three questions:

This assessment protects in both directions. It helps to avoid missing HS in a recurrent typical course. But it also prevents every painful spot in a skin fold from automatically being called HS.

What HS is not

HS is not contagious. It is also not a sign of poor hygiene. Knowing both is important medically and on a human level, because false attributions of blame can make the path to care unnecessarily difficult.

HS is also not the same as acne vulgaris. The similar name should not obscure the fact that these conditions are described and classified differently. If an area is new, unusually located or acutely much worse, treating clinicians need to consider other causes as well.

Why the term matters for the diagnosis

If you know the name, you can describe more precisely what is happening: recurrent nodules, typical body regions, pain, discharge, scars and the burden in everyday life. It is exactly these clinical patterns that help with the assessment.

A brief progress note can be more helpful than searching for the perfect technical wording. Make a note of the body site, recurrence, pain, discharge, scars and any limitations in sitting, walking, arm movement, sleep or clothing.

When you should seek medical help

If painful nodules or abscesses repeatedly occur in the armpits, groin, breast fold, genital area or on the buttocks, a dermatological consultation is worthwhile. Early recognition can prevent many individual acute events from being treated without seeing the common connection.

In cases of fever, rapid worsening, sharply increasing redness or very severe pain, medical assessment should be sought promptly.