Glossary

A painful, pus-filled swelling caused by a bacterial infection in tissue. In Acne Inversa, abscesses occur mainly in the armpits, groin, and other skin folds.

See also: Nodule , Flare

An oral retinoid used in Acne Inversa more commonly than isotretinoin. Modest evidence; significant teratogenicity — must not be used in women of childbearing potential without strict precautions.

See also: Isotretinoin , Off-Label Use

A severe, scarring form of nodulocystic acne, usually on the back, chest, and buttocks. Shares mechanistic and immunological overlap with Acne Inversa.

See also: Follicular Occlusion Tetrad , Acne Inversa (AI)

The name most commonly used in German-speaking countries for Hidradenitis Suppurativa. The condition mainly affects skin folds and is characterized by recurring nodules, abscesses, and sinus tracts. The term 'Inversa' refers to the inverted location of these skin areas compared to ordinary acne.

See also: Hidradenitis Suppurativa (HS)

A biologic drug from the class of TNF-α inhibitors and the first medication officially approved for treating moderate-to-severe Acne Inversa. It is marketed under the brand name Humira® and as biosimilars.

See also: Biologic , TNF-α Inhibitor

A seaweed-derived absorbent dressing that handles heavy drainage and forms a gel as it absorbs. Common after deroofing procedures.

See also: Hydrocolloid Dressing , Deroofing

A recombinant IL-1 receptor antagonist, daily subcutaneous injection. Used off-label in selected Acne Inversa cases, particularly autoinflammatory syndromes overlapping with HS.

See also: Biologic , IL-1 Family , Off-Label Use

A type of sweat gland concentrated in the armpits, groin, around the nipples, and the anus. Long considered the origin of Acne Inversa — hence the name 'hidradenitis' — apocrine glands sit near the follicles HS affects but are bystanders, not the trigger.

See also: Hidradenitis Suppurativa (HS) , Pilosebaceous Unit

A sunken, depressed scar.

See also: Hypertrophic Scar

A disease in which the innate immune system misfires and attacks the body's own tissue without a true infection to fight. Acne Inversa is now classified as autoinflammatory — distinct from autoimmune diseases like lupus, which are driven mainly by the adaptive immune system and antibodies.

See also: Innate Immunity , Inflammatory Infiltrate

A monoclonal antibody blocking both IL-17A and IL-17F. Approved by the FDA on 20 November 2024 as the first IL-17A and IL-17F inhibitor for adults with moderate-to-severe HS; approved by the EMA in April 2024. Brand name: Bimzelx®.

See also: Biologic , Interleukin-17 (IL-17) , Secukinumab

A structured, slime-encased community of bacteria that attaches to surfaces (including tunnel walls) and is highly resistant to antibiotics. Biofilms inside Acne Inversa tunnels are one reason oral antibiotics often fail to clear chronic disease.

See also: Dysbiosis / Microbiome , Sinus Tract

A class of medications derived from living cells that target specific components of the inflammatory process. For Acne Inversa, biologics such as adalimumab and secukinumab are used when other treatments are insufficient.

See also: Adalimumab , Secukinumab , TNF-α Inhibitor

A near-identical copy of an off-patent biologic, made by a different manufacturer and approved through a defined regulatory pathway. Biosimilars of adalimumab (and increasingly infliximab) are now widespread and dramatically cheaper than the originator — relevant to access in many countries.

See also: Biologic , Adalimumab , Infliximab

A trial in which the patient (single-blind), or both patient and investigator (double-blind), do not know who is receiving which treatment.

See also: Randomised Controlled Trial (RCT) , Placebo

Patient-community term for an inflammatory nodule or abscess. Important caveat: an ordinary single boil (furuncle) is a one-off bacterial hair-follicle infection. The recurring, multifocal 'boils' of Acne Inversa are not the same thing — this misdiagnosis is a main reason HS goes unrecognised for years.

See also: Abscess , Nodule , Diagnostic Delay

A rope-like band of scar tissue spanning two areas of formerly inflamed skin. Signals to the trained eye that destructive tunnels were once active in that region.

See also: Sinus Tract , Hurley Stage

A 10-week oral combination antibiotic regimen that has been a standard second-line option for moderate Acne Inversa for years. Effective for some patients; tolerability (gastrointestinal upset, body-fluid discoloration from rifampicin) is a real limitation.

See also: Tetracycline Antibiotics , Topical Clindamycin

Acne Inversa is diagnosed by a doctor examining the skin and taking a history — there is no blood test, biopsy, or scan that confirms HS by itself. The three classic criteria are: (1) typical lesions, (2) typical locations, and (3) chronic recurrence (at least two flares in six months).

See also: Differential Diagnosis , Hurley Stage

The four sequential stages of clinical drug development. Phase 1: small, healthy-volunteer safety. Phase 2: dose and early efficacy in patients. Phase 3: large, definitive efficacy and safety study supporting approval. Phase 4: post-marketing surveillance.

See also: Randomised Controlled Trial (RCT)

A plugged hair follicle. Open comedones are blackheads; closed comedones are whiteheads.

See also: Follicular Occlusion , Double-ended (Tombstone) Comedone

An additional condition existing alongside the primary disease. Acne Inversa is frequently associated with comorbidities including metabolic syndrome, inflammatory bowel disease, spondyloarthritis, and depression.

A scar that tightens and physically restricts movement — for example, an armpit scar limiting how far the arm can be raised. A known complication of extensive Acne Inversa or extensive HS surgery.

See also: Wide Local Excision , Hypertrophic Scar

A fluid- or keratin-filled sac under the skin. In Acne Inversa some lesions resemble epidermoid cysts but differ histologically. The term is used loosely in clinical practice.

See also: Nodule , Abscess

An older anti-inflammatory antibiotic occasionally used for mild Acne Inversa in patients who cannot tolerate other options. Requires monitoring for haemolytic anaemia.

See also: Tetracycline Antibiotics , Off-Label Use

Significantly more common in Acne Inversa than in matched controls. Should be screened for as part of comprehensive HS care, not treated as a separate issue.

See also: Stigma , Comorbidity

The medical specialty concerned with diagnosing and treating skin conditions. Acne Inversa is often managed by dermatologists, although surgery and other specialties may also be involved.

Examination of the skin with a magnifying device using polarised light. Can reveal comedones, scarring patterns, and follicular changes that support an Acne Inversa diagnosis.

See also: Clinical Diagnosis , Comedone

A surgical procedure in which the roof of an abscess or sinus tract is removed so the wound base is exposed and can heal from the inside out. Less invasive than wide local excision, it is often performed on an outpatient basis.

See also: Wide Local Excision , Sinus Tract

The average time between first symptoms and a correct Acne Inversa diagnosis. Repeatedly measured at roughly 7 to 10 years in international studies. Reducing this delay is one of the single most important advocacy goals in the HS field.

See also: Clinical Diagnosis , Differential Diagnosis

The list of other conditions a doctor must rule out before settling on Acne Inversa. Includes: simple recurrent furunculosis, cystic acne, MRSA infections, cutaneous Crohn's disease, pilonidal sinus disease, lymphogranuloma venereum, tuberculosis, and actinomycosis.

See also: Clinical Diagnosis , Pilonidal Sinus Disease , Inflammatory Bowel Disease (IBD)

Fluid coming from an Acne Inversa lesion or tunnel. Can be clear (serous), bloody (sanguineous), pus-like (purulent), or a mix.

See also: Draining Tunnel , Sinus Tract

A standardized ten-question questionnaire that measures how much a skin condition has affected a person's quality of life over the past seven days. Used in clinical trials and consultations to evaluate treatment outcomes.

See also: IHS4 Score

Two blackheads connected by a subcutaneous tunnel, breaking the surface in two places. Considered a near-pathognomonic sign of Acne Inversa — when a dermatologist sees them, HS is almost certainly the diagnosis.

See also: Comedone , Sinus Tract

A sinus tract or fistula actively leaking fluid (serous, purulent, or blood-tinged) to the surface. Draining tunnels carry the heaviest weight in modern HS severity scores because they signal long-standing, structurally damaged disease.

See also: Sinus Tract , IHS4 Score , HiSCR (Hidradenitis Suppurativa Clinical Response)

An imbalance in the community of microbes on the skin. Acne Inversa skin has a distinctively altered microbiome with more anaerobes (Prevotella, Porphyromonas) and Corynebacterium species, and less diversity than healthy skin. Whether dysbiosis causes HS or results from it is still being worked out.

See also: Biofilm , Autoinflammatory Disease

Acne Inversa that runs in families. Roughly 30–40% of patients report at least one first-degree relative with HS. Inheritance is usually autosomal dominant with incomplete penetrance — meaning the risk can be inherited without inevitably developing the disease.

See also: Sporadic HS

A specific kind of tunnel that connects an inflammatory cavity to the skin surface, allowing chronic drainage. In HS literature, 'draining tunnel' and 'fistula' are often used interchangeably.

See also: Sinus Tract , Draining Tunnel

A period of acute worsening in a chronic condition. In Acne Inversa, a flare may be triggered by stress, hormonal changes, friction, or other factors and can manifest as new nodules, abscesses, or increased pain.

See also: Remission , Abscess

The blockage of hair follicles is considered a key starting point in the development of Acne Inversa. When a follicle becomes obstructed, inflammation can spread deep into tissue, leading to nodules, abscesses, and sinus tracts.

See also: Acne Inversa (AI) , Nodule

A historical grouping of four conditions thought to share follicular plugging as the underlying mechanism: (1) Acne Inversa / HS, (2) acne conglobata, (3) dissecting cellulitis of the scalp, and (4) pilonidal sinus disease. Patients sometimes have more than one of the four.

See also: Acne Conglobata , Pilonidal Sinus Disease

When a blocked follicle bursts under pressure, dumping keratin, hair fragments, bacteria, and oil into surrounding tissue. The immune system reads this as a foreign invasion and launches the intense inflammatory response that produces nodules, abscesses, and tunnels.

See also: Follicular Occlusion , Nodule , Abscess

Loose, breathable clothing; cotton or moisture-wicking fabrics; bras and underwear without seams over typical Acne Inversa sites. Friction is a documented mechanical trigger.

See also: Intertriginous Area , Flare

A walled-off cluster of immune cells around persistent irritants — in Acne Inversa, around ruptured follicular debris. Granulomas contribute to the chronic, lumpy, scarred quality of long-standing HS skin.

See also: Inflammatory Infiltrate , Autoinflammatory Disease

The tube-shaped pocket in the skin from which a hair grows. In Acne Inversa, the follicle becomes plugged and eventually ruptures, spilling its contents into surrounding tissue and triggering the inflammatory cascade that defines the disease.

See also: Follicular Occlusion , Follicular Rupture

The internationally used medical term for Acne Inversa. It is a chronic inflammatory skin condition primarily affecting body areas subject to friction and perspiration. HS is not an infectious disease and is not contagious.

See also: Acne Inversa (AI) , Hurley Stage

An imaging technique using high-resolution ultrasound to visualise subclinical fluid collections and tunnels invisible to the naked eye. Increasingly used to upstage Hurley scores and to plan surgery. Not yet routine outside specialised HS centres.

See also: Hurley Stage , Sinus Tract , Clinical Diagnosis

The dichotomous response criterion that became the regulatory standard in the adalimumab trials. HiSCR50 is met when: (1) the combined count of abscesses and inflammatory nodules drops ≥50%, (2) the number of abscesses does not increase, and (3) the number of draining tunnels does not increase. HiSCR75, HiSCR90, and HiSCR100 apply the same logic at higher thresholds.

See also: IHS4 Score , IHS4-55 , Adalimumab

A 17-item HS-specific quality-of-life questionnaire validated in the late 2010s. More sensitive to HS-specific concerns (drainage, odour, intimacy) than the general DLQI.

See also: DLQI (Dermatology Life Quality Index) , Patient-Reported Outcomes (PROs)

Often described as throbbing, burning, sharp, or pressure-like. Can be nociceptive (inflammation-driven) and, in long-standing disease, also neuropathic (nerve-damage-driven). Pain in HS is consistently rated more severe than in psoriasis and most other chronic skin diseases — a fact still underestimated in many clinics.

See also: Pain NRS (Numeric Rating Scale) , Flare , Pruritus (Itch)

A six-point scale (clear, minimal, mild, moderate, severe, very severe) assigned by the dermatologist based on counts of abscesses, draining tunnels, and inflammatory nodules. Quick to use but coarse.

See also: IHS4 Score , HiSCR (Hidradenitis Suppurativa Clinical Response)

A clinical classification system for assessing the severity of Acne Inversa in three stages: Stage I (single abscesses without sinus tracts), Stage II (recurrent abscesses with isolated sinus tracts), Stage III (extensive sinus tracts and scarring across an entire region). Named after Dr. Helen Hurley.

See also: Sinus Tract , IHS4 Score

A flexible, self-adhesive dressing that absorbs small amounts of fluid and keeps the wound moist. Suitable for low-drainage Acne Inversa lesions.

See also: Alginate Dressing , Secondary Intention Healing

An excess buildup of keratin in the outer layers of skin or inside a follicle. Hyperkeratosis of the follicular wall physically blocks the follicle, setting the first step of Acne Inversa pathology in motion.

See also: Follicular Occlusion , Comedone

A raised, thickened scar that stays within the original wound boundary. Common after Acne Inversa surgery, especially in skin folds.

See also: Keloid , Wide Local Excision

A validated tool for measuring disease activity in Acne Inversa. The score takes into account the number of nodules, abscesses, and draining sinus tracts, enabling objective assessment of current status and treatment response.

See also: DLQI (Dermatology Life Quality Index) , Hurley Stage

A dichotomous response criterion developed and validated in 2022. A patient is a responder if their IHS4 score drops by at least 55% from baseline. Increasingly used as a clinical trial endpoint because it captures meaningful improvement across all three lesion types, including tunnels.

See also: IHS4 Score , HiSCR (Hidradenitis Suppurativa Clinical Response)

A group of cytokines (IL-1α, IL-1β, IL-36) implicated in Acne Inversa inflammation. Drugs targeting IL-1 (anakinra, canakinumab) and IL-36 are under investigation but not yet routine.

See also: Anakinra , Autoinflammatory Disease

A small cut to drain an acute, fluctuant abscess. Provides fast pain relief but does not prevent recurrence in Acne Inversa — the abscess almost always returns at the same site. Should not be considered definitive HS treatment.

See also: Abscess , Deroofing

Crohn's disease and, less commonly, ulcerative colitis. Acne Inversa patients have a several-fold higher risk of IBD than the general population. If you have HS and unexplained chronic diarrhoea, weight loss, abdominal pain, or perianal disease, a gastroenterology referral is warranted.

See also: Comorbidity , Differential Diagnosis

The crowd of immune cells (neutrophils, macrophages, T cells, B cells) that flood into Acne Inversa lesions. Their role should be protective, but in HS the response is exaggerated, prolonged, and damaging.

See also: Autoinflammatory Disease , Follicular Rupture

A TNF-α-blocking antibody given by intravenous infusion. Used off-label in Acne Inversa, often at higher-than-rheumatology doses, particularly in severe refractory cases or where IBD coexists. Brand name: Remicade® and biosimilars.

See also: TNF-α Inhibitor , Biologic , Off-Label Use

The fast, broad, non-specific arm of the immune system: neutrophils, macrophages, complement, cytokines. The dominant problem in Acne Inversa.

See also: Autoinflammatory Disease , Inflammatory Infiltrate

Inflammatory cytokines (IL-17A and IL-17F) that drive neutrophil recruitment and tissue damage in Acne Inversa. IL-17A is blocked by secukinumab; both IL-17A and IL-17F are blocked by bimekizumab.

See also: Secukinumab , Bimekizumab , Autoinflammatory Disease

A cytokine upstream of the IL-17 response. Ustekinumab (anti-IL-12/23) and risankizumab (anti-IL-23) have been tried in Acne Inversa off-label with mixed results.

See also: Ustekinumab , Interleukin-17 (IL-17)

Skin folds where two surfaces rub together: armpits, groin, inner thighs, under the breasts, between the buttocks, anal region, and lower abdomen in people with abdominal overhang. Acne Inversa overwhelmingly targets these areas.

See also: Acne Inversa (AI) , Friction Reduction

A small injection of steroid (typically triamcinolone acetonide) directly into an inflamed nodule or abscess. Can shrink lesions and reduce pain within 24–72 hours. The closest thing Acne Inversa has to an emergency brake for an individual flare.

See also: Abscess , Nodule , Flare

An oral retinoid primarily used for severe acne. It is sometimes tried in Acne Inversa, although evidence for its effectiveness in HS is limited. Use requires strict medical supervision due to potential side effects.

See also: Biologic

An intracellular signalling system that relays cytokine messages from the cell surface to the nucleus. Several cytokines relevant to Acne Inversa use this pathway. Drugs blocking specific JAKs — particularly JAK1 inhibitors like povorcitinib and upadacitinib — are now in late-stage HS development.

See also: Povorcitinib , Upadacitinib

A scar that grows beyond the original wound boundary. More common in patients with darker skin tones. Not the same as a hypertrophic scar.

See also: Hypertrophic Scar

Long-wavelength lasers (Nd:YAG, alexandrite, diode) that destroy hair follicles. Repeated treatments in HS-prone areas can reduce flare frequency, particularly in early-stage disease. The best evidence is for Nd:YAG.

See also: Follicular Occlusion , Hair Follicle

The smell that can come from draining Acne Inversa lesions, caused by anaerobic bacteria in tunnels. A major source of social distress that patients almost never mention to their doctors unprompted.

See also: Draining Tunnel , Stigma , Dysbiosis / Microbiome

A cluster of cardiovascular risk factors — central obesity, raised blood pressure, raised fasting glucose, abnormal cholesterol. Significantly more common in Acne Inversa patients than in the general population, independent of weight alone.

See also: Comorbidity , Polycystic Ovary Syndrome (PCOS)

A diabetes drug that also reduces insulin resistance. Modest evidence for Acne Inversa benefit, particularly in patients with metabolic syndrome or PCOS. Cheap and widely tolerated.

See also: Metabolic Syndrome , Polycystic Ovary Syndrome (PCOS) , Off-Label Use

A vacuum-assisted dressing system that promotes wound healing by secondary intention. Common after large Acne Inversa excisions.

See also: Secondary Intention Healing , Wide Local Excision

A firm, palpable lump deep in tissue. Nodules can be painful and may progress to abscesses. They are among the typical early signs of Acne Inversa.

See also: Abscess , Hurley Stage

Prescribing an approved drug for a condition outside its label. Common in Acne Inversa because the approved-drug list is short and patient need is high. Insurance reimbursement for off-label use varies widely by country and payer.

See also: Biologic

A trial in which everyone knows what treatment is being given. Common for extension studies after a blinded core trial.

See also: Blinded Study , Randomised Controlled Trial (RCT)

A psychological pattern in which pain feels uncontrollable and overwhelming, predicting worse pain outcomes independent of disease severity. Specific psychological treatments can help. Acknowledging the pattern is not the same as saying the pain is not real.

See also: HS Pain , Depression and Anxiety

A simple 0-to-10 self-report of worst skin pain in the past 24 hours or past 7 days. The international standard for measuring Acne Inversa pain in trials and increasingly in routine care.

See also: HS Pain , Patient-Reported Outcomes (PROs)

A small, solid raised bump in the skin, usually under 1 cm. Often the very first visible sign of Acne Inversa.

See also: Nodule , Pustule

Any measure where the score comes from the patient rather than the physician — DLQI, HiSQoL, pain NRS. The HS field has, until recently, undervalued PROs. That is changing fast.

See also: DLQI (Dermatology Life Quality Index) , HiSQoL (Hidradenitis Suppurativa Quality of Life) , Pain NRS (Numeric Rating Scale)

Patient communities — in person and online — consistently reported as meaningfully beneficial by Acne Inversa patients, both informationally and emotionally. A useful adjunct, not a substitute for medical care.

See also: Stigma

Chronic inflammation, abscesses, and tunnels at the top of the buttock crease, often triggered by an ingrown hair. Frequently co-exists with Acne Inversa.

See also: Follicular Occlusion Tetrad , Sinus Tract

The combined structure of a hair, its follicle, and the attached sebaceous (oil) gland. Acne Inversa is now classified as a disease of the pilosebaceous unit, not of sweat glands as was long incorrectly assumed.

See also: Follicular Occlusion , Hair Follicle

An inactive substance, usually identical in appearance to the real drug, used in clinical trials to control for the meaningful placebo response in Acne Inversa.

See also: Randomised Controlled Trial (RCT) , Blinded Study

A hormonal condition involving irregular menstruation, excess androgens, ovarian cysts, and insulin resistance. Co-occurs with Acne Inversa at higher-than-expected rates, particularly in women whose HS flares with the menstrual cycle.

See also: Metabolic Syndrome , Spironolactone

An oral, selective JAK1 inhibitor from Incyte (development name INCB54707). In March 2025 Incyte announced positive topline results from the pivotal Phase 3 STOP-HS program (STOP-HS1 and STOP-HS2) in adults with moderate-to-severe HS — both studies met their primary endpoint. Not yet approved at time of writing.

See also: JAK/STAT Pathway , HiSCR (Hidradenitis Suppurativa Clinical Response)

Reduced ability to work effectively because of disease, even when physically present. Acne Inversa has measurable economic impact through absenteeism and presenteeism, often hidden because patients do not disclose the diagnosis to employers.

See also: Stigma , DLQI (Dermatology Life Quality Index)

Itch. Often overlooked in Acne Inversa because pain dominates, but a significant minority of patients rate itch as the most distressing symptom, particularly during the healing phase of lesions.

See also: HS Pain , Flare

A miniature deroofing using a small circular punch tool, suitable for individual recurrent nodules. Office-based, fast, local anaesthetic only.

See also: Deroofing , Incision and Drainage (I&D)

A pus-filled bump on the skin surface. Smaller and more superficial than an abscess.

See also: Abscess , Papule

A rare, painful, ulcerative skin condition that sometimes occurs alongside Acne Inversa.

See also: Comorbidity

A study in which patients are randomly assigned to receive either the experimental treatment or a comparator (placebo or another treatment). The gold standard for testing whether a treatment actually works.

See also: Placebo , Blinded Study

Data from patients treated outside clinical trials — registries, electronic health records, claims databases. Increasingly important in Acne Inversa because trial patients are often more selected than the real HS population.

See also: Randomised Controlled Trial (RCT)

A phase in which disease activity significantly decreases or is temporarily not noticeable. Complete cure in Acne Inversa is rare; however, remissions are possible and an important treatment goal.

See also: Flare

A keratolytic chemical peel agent (typically 15%) applied at home to dissolve follicular plugs. Used long-term in some specialist centres for mild-to-moderate Acne Inversa, particularly in Europe.

See also: Follicular Occlusion , Topical Clindamycin

Rinsing tunnels and wounds with sterile saline. Sounds basic — it is. It also remains one of the most consistently useful self-care steps for active Acne Inversa lesions.

See also: Sinus Tract , Draining Tunnel

Letting the wound heal on its own from the bottom up, without stitches. Slower (weeks to months) but consistently the lowest-recurrence option for Acne Inversa surgery in moist, mobile body sites.

See also: Deroofing , Wide Local Excision

A biologic drug that inhibits the inflammatory messenger interleukin-17A (IL-17A). Secukinumab was approved as the second biologic for treating Acne Inversa and is available under the brand name Cosentyx®.

See also: Biologic , Adalimumab

Acne Inversa frequently affects the groin, buttocks, inner thighs, and breasts — anatomy directly relevant to intimacy. Pain, drainage, scarring, and self-image effects on sexual function are well documented and routinely under-addressed in clinic.

See also: Stigma , DLQI (Dermatology Life Quality Index) , HiSQoL (Hidradenitis Suppurativa Quality of Life)

A tunnel-like channel under the skin that forms between abscesses or nodules. Sinus tracts indicate more advanced disease and can chronically drain fluid. They are associated with Hurley Stages II and III.

See also: Hurley Stage , Abscess

Sitting in a shallow bath of warm water (sometimes with Epsom salts or dilute antiseptic) to soothe perianal and gluteal Acne Inversa lesions.

See also: Saline Irrigation

A small sample of skin removed for microscopic examination. Not required to diagnose Acne Inversa, but sometimes used to exclude mimics — particularly cutaneous Crohn's disease, infections, or skin cancer arising in chronic HS scars.

See also: Clinical Diagnosis , Differential Diagnosis

The single most evidence-supported lifestyle change in Acne Inversa. Benefit is real but often slow — many patients see improvement over months, not weeks.

See also: Flare

A potassium-sparing diuretic with anti-androgen activity. Used off-label in women with Acne Inversa, particularly those with flares around menstruation, hirsutism, or PCOS features. Cannot be used in pregnancy.

See also: Polycystic Ovary Syndrome (PCOS) , Off-Label Use

A family of inflammatory joint and spine conditions (including ankylosing spondylitis, psoriatic arthritis) that overlap with Acne Inversa. If you have HS and unexplained inflammatory back pain (morning stiffness lasting more than 30 minutes, better with movement), an assessment is worthwhile.

See also: Comorbidity

Acne Inversa in a patient with no known family history. The majority of cases.

See also: Familial HS

Skin-Tissue-sparing Excision with Electrosurgical Peeling — a surgical technique using electrosurgery to remove HS-affected tissue while preserving as much healthy skin as possible. A halfway house between deroofing and wide local excision.

See also: Deroofing , Wide Local Excision

The social devaluation patients experience because of visible or smellable Acne Inversa. Documented across cultures. A predictor of depression, social withdrawal, and employment difficulty — and one of the reasons patient education and visibility campaigns matter.

See also: Depression and Anxiety , Sexual Dysfunction , Malodor

Doxycycline, minocycline, lymecycline. Long courses (3+ months) are first-line oral therapy for mild-to-moderate Acne Inversa in most guidelines. The benefit is at least partly anti-inflammatory, not just antibacterial.

See also: Topical Clindamycin , Clindamycin + Rifampicin

A group of biologic drugs that block tumor necrosis factor alpha (TNF-α), a key inflammatory mediator. Adalimumab is the best-known TNF-α inhibitor approved for Acne Inversa.

See also: Adalimumab , Biologic

An antibiotic lotion or gel applied directly to the skin. First-line topical treatment for mild Acne Inversa in most guidelines.

See also: Tetracycline Antibiotics , Clindamycin + Rifampicin

A patient-kept log of flares alongside menstrual cycle, food, stress, sleep, weather, clothing, and activity. Most useful for identifying personal triggers, since population-level HS trigger data are weak.

See also: Flare

An oral JAK1 inhibitor already approved for rheumatoid arthritis, psoriatic arthritis, atopic dermatitis, ulcerative colitis, and Crohn's disease. Studied off-label and in trials for Acne Inversa. Brand name: Rinvoq®.

See also: JAK/STAT Pathway , Off-Label Use

An antibody against the shared IL-12/IL-23 p40 subunit. Used off-label in Acne Inversa with modest, inconsistent results. Brand name: Stelara®.

See also: Biologic , Interleukin-23 (IL-23) , Off-Label Use

Historical name for Hidradenitis Suppurativa, named after the French surgeon Aristide Verneuil who described the condition in the 1850s. Still occasionally used in French-language medicine and academic writing.

See also: Hidradenitis Suppurativa (HS) , Acne Inversa (AI)

A surgical procedure in which affected skin areas are completely removed along with a safety margin. Wide local excision is the most effective surgical approach for advanced Acne Inversa but requires a longer healing period.

See also: Deroofing , Hurley Stage