Topic 5: Recognizing Moderate Disease in Practice
IHS4 provides a validated numerical definition of moderate inflammatory activity, but clinicians should not rely on one scoring system alone.
A 2026 expert framework proposed that HS may be considered moderate when any of the following is present:5
- HS symptoms remain inadequately controlled with conventional therapies
- One inflamed tunnel is present, whether draining or nondraining
- At least four inflammatory lesions, including nodules and abscesses, involve at least two anatomic areas
The framework is intended to help clinicians identify patients who may benefit from more prompt or targeted treatment before extensive irreversible damage develops. It is an expert proposal, not a universally adopted severity definition.
Several additional findings can suggest that disease is more significant than it initially appears:
- Frequent or prolonged flares
- Persistent inflammatory activity
- Multiregional involvement
- Increasing lesion counts
- A new or extending tunnel
- Moderate or severe pain
- Meaningful quality-of-life impairment
- Functional limitations
- Inadequate control with previous treatment
| Important distinction: Pain, flare frequency, treatment failure, and quality-of-life impairment are important assessments that can identify disease severity, regardless of the burden of visible lesions present on exam at the time of examination. |