Hidradenitis suppurativa (HS) can, in rare cases, lead to sepsis when bacteria from infected lesions enter the bloodstream. But there’s an important nuance: severe HS flares frequently mimic sepsis with fever, elevated white blood cell counts, and fatigue, even when no true bloodstream infection is present. This distinction matters because it affects how the condition is treated in an emergency and what you should watch for at home.
How HS Could Lead to Sepsis
HS creates deep, recurring abscesses in areas like the groin, armpits, and under the breasts. These abscesses sit beneath the skin in warm, moist environments where bacteria thrive. When lesions rupture, drain incompletely, or become secondarily infected, bacteria have a potential route into surrounding tissue and, eventually, the bloodstream.
The bacteria most commonly found in HS lesions aren’t always the usual suspects. A French study of HS patients found that a species called Staphylococcus lugdunensis was the dominant bacterium in 58% of nodules and abscesses. Chronic, continuously draining lesions harbored a more complex mix: 87% contained a combination of anaerobic bacteria (organisms that grow without oxygen), streptococci, and other microbes. Staphylococcus aureus, the bacterium most people associate with skin infections, was present but less consistently than expected. Streptococcus anginosus, a bacterium specifically linked to abscess formation, appeared repeatedly across multiple studies and may play a role in driving both chronic inflammation and systemic symptoms.
For sepsis to develop, these bacteria need to overwhelm local defenses and spread beyond the skin. This is more likely when abscesses are large, deep, or left untreated for extended periods. People with compromised immune function face higher risk, which brings up an important complication specific to HS patients.
Why Immunosuppressive Treatment Adds Risk
Many people with moderate to severe HS take biologic medications or corticosteroids to control inflammation. These drugs work by dialing down the immune system, which helps reduce painful flares but also makes the body less effective at containing infections. In a case series of six HS patients hospitalized with signs resembling sepsis, five were on biologic therapy and three were taking corticosteroids at the time of admission.
This creates a difficult clinical situation. Immunosuppressive drugs can mask the typical warning signs of a spreading infection by blunting the body’s inflammatory response. A fever that would normally spike high might stay low. White blood cell counts that should rise dramatically might increase only modestly. At the same time, these medications can make a person more susceptible to secondary infections in the first place. If you’re on biologic therapy or corticosteroids for HS, changes in how your flares feel or behave deserve extra attention.
HS Flares That Look Like Sepsis but Aren’t
This is where the picture gets complicated. HS is fundamentally an immune-mediated disease, not just an infection. During severe flares, your body mounts a powerful inflammatory response that can produce fever, rapid heart rate, elevated white blood cell counts, and profound fatigue. These are the exact same signs doctors use to identify sepsis. A case series published in JAAD Case Reports documented this pattern, finding that acute HS flares closely mimicked sepsis or severe soft tissue infections, frequently triggering emergency department visits and hospital admissions.
The medical term for this overlap is systemic inflammatory response syndrome (SIRS). Your body is genuinely inflamed and showing measurable signs of distress, but the cause is your own immune system’s overreaction rather than bacteria circulating in your blood. Standard screening criteria for sepsis tend to overestimate actual infection in people with HS, particularly those already on immune-modulating treatments. This means some HS patients end up receiving aggressive antibiotic courses or invasive workups for infections that aren’t there, while the real issue is an uncontrolled flare.
That said, distinguishing a severe flare from true sepsis isn’t something you can do on your own. Blood cultures, imaging, and clinical assessment are needed to tell the difference.
Warning Signs That Need Emergency Care
Whether the cause turns out to be a severe flare or an actual infection, certain symptoms signal that your body is in serious trouble. Early warning signs include:
- High fever or unusually low body temperature
- Chills and shivering
- Rapid heartbeat or fast breathing
More advanced symptoms that suggest the situation is escalating include confusion or disorientation, dizziness or feeling faint, severe muscle pain, significant drop in urine output, and skin that looks mottled, pale, or feels cold and clammy. Slurred speech or loss of consciousness are late-stage signs that require immediate emergency intervention.
For HS patients specifically, pay attention to flares that feel different from your usual pattern. A lesion that spreads rapidly into surrounding skin, redness that extends well beyond the borders of a known abscess, or systemic symptoms (fever, chills, confusion) appearing alongside a flare are all reasons to seek urgent evaluation. This is especially true if you’re on immunosuppressive therapy, since your body’s ability to fight off a spreading infection is reduced.
How Infected HS Lesions Are Managed
Treatment depends on severity. For mild disease, oral antibiotics from the tetracycline family or topical antibiotics applied directly to the skin are typical first steps. These target both bacteria and inflammation. Hormonal therapies are sometimes used alongside antibiotics for additional control.
Severe or treatment-resistant cases may require broader-spectrum antibiotics, and in some situations, intravenous antibiotics are used when oral options haven’t worked. Corticosteroids are sometimes given as short-term rescue therapy during acute flares, though their use requires balancing the benefit of reducing inflammation against the risk of further suppressing the immune system.
Surgical drainage of large or deep abscesses is often necessary when lesions don’t resolve with medication alone. Removing the source of potential bacterial spread is one of the most direct ways to reduce the risk of a localized infection becoming systemic. For people with chronic, tunnel-forming disease, more extensive surgical procedures may be recommended to eliminate the interconnected tracts where bacteria persistently colonize.
The key takeaway is that while true sepsis from HS is uncommon, the conditions that could lead to it (deep abscesses, secondary bacterial infection, immunosuppression) are part of the everyday reality of living with this disease. Recognizing when a flare is behaving unusually and getting prompt evaluation can make the difference between managing an infection early and dealing with a dangerous escalation.