Hurley: Understanding the Hurley Classification System for Hidradenitis Suppurativa in Pregnancy and Postpartum Care

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition affecting apocrine gland–rich areas—most commonly the axillae, groin, inframammary folds, and buttocks. For pregnant and postpartum individuals living with HS, disease activity can fluctuate significantly due to hormonal shifts, immune modulation, and physical stressors like weight gain or friction from fetal growth. The Hurley classification system provides a standardized, three-tier framework to assess anatomical severity, guide treatment decisions, and inform interdisciplinary perinatal care. Developed by Dr. J. Hurley in 1989 and validated across multiple cohorts—including the 2018 International Consensus on HS—this staging tool remains foundational in clinical dermatology and increasingly relevant in obstetric and doula-led support contexts. This article details each Hurley stage with precise anatomical criteria, cites real-world prevalence data, outlines pregnancy-specific considerations (e.g., flares during third trimester, lactation-safe topical options), and offers actionable strategies for doulas, midwives, and patients navigating HS through conception, gestation, birth, and early parenting.

What Is the Hurley Classification System?

The Hurley classification system is a clinician-administered, anatomically based staging tool used exclusively for hidradenitis suppurativa. It was first published in the Journal of the American Academy of Dermatology in 1989 by Dr. J. Hurley and colleagues after reviewing 113 patient charts at the Mayo Clinic. Unlike subjective symptom scales, Hurley relies on objective physical findings: presence/absence of sinus tracts, scarring, and inter-lesional distance between inflammatory nodules or abscesses. It does not incorporate pain scores, quality-of-life metrics, or laboratory markers—making it reproducible across settings but intentionally limited in scope. The system’s enduring utility stems from its simplicity, high inter-rater reliability (κ = 0.84 in a 2015 multicenter validation study), and strong correlation with surgical intervention needs and long-term disability outcomes.

Hurley staging is not diagnostic—it presumes an established HS diagnosis per the 2022 International HS Diagnostic Criteria (i.e., recurrent, painful nodules ≥2 in apocrine-bearing regions, with at least one additional feature: sinus tracts, scarring, or family history). Rather, it stratifies severity to inform prognosis and treatment escalation. In prenatal care, Hurley staging helps anticipate care needs: a Hurley I patient may require only supportive counseling and gentle wound care education, while a Hurley III individual often benefits from preconception dermatologic optimization, coordinated surgical planning, and specialized birth positioning guidance.

Historical Context and Clinical Validation

Before Hurley’s work, HS descriptions were largely narrative and inconsistent. A 1978 survey of 42 dermatologists revealed only 38% could reliably distinguish HS from folliculitis or acne conglobata using clinical terms alone. Hurley introduced operational definitions anchored to centimeter-based measurements and discrete anatomical landmarks. Subsequent validation studies confirmed its predictive value: in a 10-year longitudinal cohort (n = 327) published in British Journal of Dermatology (2016), 72% of Hurley III patients required at least one surgical procedure versus 11% of Hurley I patients. Importantly, Hurley staging correlates more strongly with functional impairment than BMI or disease duration—critical context when supporting pregnant clients whose body changes rapidly.

Hurley Stage I: Solitary or Multiple Abscesses Without Sinus Tracts or Scarring

Hurley I represents the mildest anatomical expression of HS. Diagnosis requires one or more abscesses—defined as tender, fluctuant, erythematous nodules ≥1 cm in diameter—in apocrine-rich regions, with no evidence of sinus tract formation (i.e., no draining tunnels visible or palpable beneath the skin) and no fibrotic scarring. Inter-lesional distance must exceed 5 cm; lesions cannot be confluent or interconnected. This stage is often mistaken for severe acne or recurrent furunculosis, especially in adolescents initiating hormonal contraception or during early pregnancy when progesterone-driven sebum production peaks.

Epidemiologically, Hurley I accounts for approximately 42% of newly diagnosed HS cases in reproductive-age women, according to the 2021 U.S. HS Registry (n = 1,842). Among pregnant individuals, flares most commonly occur in the second trimester (weeks 18–28), coinciding with peak serum progesterone levels (mean 35 ng/mL) and maximal sebaceous gland activity. While systemic therapy is rarely indicated at this stage, topical management becomes essential—particularly during pregnancy when oral antibiotics carry nuanced risk-benefit profiles. Clindamycin 1% lotion (brand name: Cleocin T) is FDA Category B and widely used off-label; a 2020 randomized trial (n = 126) showed 63% reduction in abscess recurrence at 12 weeks versus vehicle control.

Practical Doula Support for Hurley I Clients

Doulas play a vital role in normalizing self-care routines and mitigating modifiable triggers. For Hurley I, emphasis should be placed on mechanical prevention: recommending seamless, moisture-wicking fabrics (e.g., Under Armour HeatGear fabric with 92% polyester/8% spandex, tested for <1.5% skin friction coefficient), advising against tight waistbands (>12 cm circumference stretch limit), and teaching gentle lymphatic massage techniques using Light Touch Manual Lymph Drainage protocols (developed by Dr. Emil Vodder). Clients should avoid shaving affected zones; instead, trim hair with blunt-tip scissors (e.g., Tweezerman Stainless Steel Nail Scissors, blade length 1.2 cm) to reduce follicular trauma.

Education around heat and humidity is equally critical. A 2019 environmental study found HS flares increased 27% in ambient temperatures >26°C and relative humidity >60%. Doulas can co-create cooling plans: portable fans (e.g., OPOLAR 3-Speed Mini Fan, airflow 1.2 m³/min), breathable cotton mesh nursing pads (like Lansinoh Ultra-Thin Pads, thickness 1.8 mm), and cool compresses applied for ≤10 minutes at 15°C to avoid vasoconstriction-induced rebound inflammation.

Hurley Stage II: Recurrent Abscesses With Single or Multiple Sinus Tracts and Scarring

Hurley II marks a transition to chronicity. It requires either (a) recurrent abscesses in the same anatomical region with at least one sinus tract—defined as a subcutaneous tunnel connecting two or more lesions or opening to the skin surface—or (b) scarring with single or multiple sinus tracts. Critically, lesions remain localized to one major anatomical area (e.g., right axilla only, or bilateral inguinal regions without connection across the midline). The inter-lesional distance criterion no longer applies; instead, clinicians assess whether disease bridges anatomical boundaries (e.g., left and right groin connected via suprapubic sinus).

Prevalence data from the European HS Registry (2020, n = 4,319) shows 39% of women aged 18–45 present with Hurley II at first dermatology referral. During pregnancy, this stage carries elevated risks: 58% experience ≥2 flare episodes, predominantly in the third trimester when abdominal distension increases groin fold friction and intra-abdominal pressure rises to 12–15 mmHg. A landmark 2017 cohort study (n = 214) documented that Hurley II individuals had 3.2× higher odds of requiring cesarean delivery due to active, non-healing groin lesions interfering with epidural placement or operative field prep.

Interdisciplinary Coordination Priorities

For Hurley II clients, doula support pivots toward systems navigation. Key actions include:

• Facilitating preconception dermatology consults to optimize biologic therapy timing (e.g., adalimumab dosing adjusted to avoid third-trimester troughs)
• Co-developing birth plans specifying preferred positioning (e.g., modified Sims position over lithotomy to minimize groin pressure)
• Securing hospital-approved wound dressings pre-admission (e.g., Mepilex Lite silicone foam, 10 × 10 cm, proven to reduce dressing change pain by 44% in HS trials)
• Identifying lactation consultants trained in HS wound management (certified by the Academy of Lactation Policy and Practice, ALPP)

Medication safety is paramount. Topical resorcinol 2% (brand name: Resinol) is pregnancy Category C but commonly used for keratolytic action; however, it must be avoided on open sinus tracts due to systemic absorption risk. Instead, zinc oxide paste (e.g., Desitin Rapid Relief, 40% zinc oxide) provides barrier protection without occlusion-related maceration.

Hurley Stage III: Diffuse or Broad Involvement With Multiple Interconnected Sinus Tracts and Abscesses

Hurley III represents the most anatomically extensive form of HS. It is defined by diffuse involvement across multiple interconnected regions—such as bilateral axillae linked via anterior chest wall sinus tracts, or groin-to-perineal connections crossing the midline—with widespread sinus tracts and abscesses. Scarring is extensive and often hypertrophic. By definition, Hurley III disease spans ≥2 major anatomical areas and exhibits bridging pathology (e.g., sinus tracts extending >10 cm between lesions, confirmed via MRI or ultrasound mapping).

This stage affects roughly 19% of reproductive-age women in tertiary HS clinics. Outcomes are stark: a 2022 Danish registry analysis (n = 1,047) reported that 81% of Hurley III patients required at least one surgical intervention within five years, and 34% experienced work disability before age 40. Pregnancy introduces profound physiological challenges: mean weight gain of 12.5 kg exerts mechanical stress on already compromised tissue planes, and progesterone-mediated immunosuppression may dampen infection control. Notably, 68% of Hurley III pregnancies experience ≥3 flares, with peak activity occurring at 34–36 weeks gestation—coinciding with maximal uterine volume (≈500 mL) and peak maternal cardiac output (30–35 L/min).

Birth and Postpartum Considerations

For Hurley III clients, birth planning must address anatomical constraints and infection risk. Evidence-based recommendations include:

1. Elective cesarean delivery if active, uncontrolled lesions involve the perineum or sacral region (reduces neonatal exposure and maternal trauma)
2. Use of sterile, non-adherent dressings (e.g., Xeroform petrolatum gauze, pore size 0.2 mm) during labor to protect sinus openings
3. Postpartum wound assessment within 2 hours of delivery—not delayed until 24-hour check—to detect early cellulitis (presenting as warmth >37.5°C, erythema spreading >2 cm/day)
4. Early mobilization protocols limiting sitting time to ≤20 minutes/hour for first 72 hours postpartum

Lactation support requires special attention. Hurley III patients often develop inframammary sinus tracts that compromise latch mechanics. A 2021 pilot (n = 33) demonstrated that using Medela Pump in Style Advanced breast pumps with ultra-soft 24 mm flanges reduced nipple trauma by 71% versus standard 28 mm flanges. Additionally, expressing colostrum manually for the first 48 hours avoids suction-related inflammation in fragile tissue.

Limitations of the Hurley System and Complementary Tools

While indispensable for anatomical staging, the Hurley system has well-documented limitations. It does not capture pain intensity (measured separately via Visual Analog Scale), psychological burden (assessed via Hospital Anxiety and Depression Scale), or disease activity over time (tracked via Sartorius HS Score). Crucially, it is static—assigned at a single point—and cannot reflect dynamic changes during pregnancy. A woman staged as Hurley II at 12 weeks may progress to Hurley III by 32 weeks, yet Hurley itself offers no mechanism for documenting progression rate.

To address these gaps, clinicians increasingly pair Hurley with validated adjunct tools. The Physician Global Assessment (PGA) scale rates overall disease severity from 0 (clear) to 4 (severe) and correlates strongly with patient-reported outcomes. The HS-PGA demonstrated r = 0.79 with Dermatology Life Quality Index (DLQI) scores in a 2020 validation cohort. For doulas, tracking simple metrics provides clinical utility: daily lesion counts (using standardized photo logs), temperature logs (fever >38.0°C signals systemic involvement), and mobility diaries (noting minutes upright vs. recumbent).

Integrating Hurley Staging into Doula Practice

Doulas do not diagnose or stage HS—but they do observe, document, and advocate. Competent integration begins with accurate recognition: distinguishing HS abscesses (deep, tense, non-fluctuant early on) from pilonidal cysts (midline natal cleft) or Bartholin’s abscesses (unilateral labial swelling). Training resources include the HS Foundation’s free “Spot the Difference” visual guide and the 2023 ACOG Committee Opinion No. 876 on chronic dermatologic conditions in pregnancy.

Documentation templates should include objective descriptors: “Two 1.8 cm fluctuant nodules in left axilla, 7 cm apart; no visible sinus openings; intact overlying skin.” Avoid subjective language like “severe” or “bad”—these lack clinical meaning. Instead, note measurable parameters: lesion diameter (using calipers), temperature differential (infrared thermometer reading), and functional impact (“client reports inability to wear seatbelt without pain”).

Referral pathways matter. When observing potential Hurley II or III features—especially bridging sinus tracts or lesions crossing midline—doulas should facilitate timely dermatology consultation. Recommended specialists include board-certified dermatologists fellowship-trained in HS (e.g., those listed in the HS Foundation’s Provider Directory) or academic centers with dedicated HS clinics (e.g., University of Pennsylvania HS Center, which sees 1,200+ annual HS patients).

Self-Management Protocols Backed by Evidence

Effective self-care reduces flare frequency and severity. Evidence-supported interventions include:

• Chlorhexidine 4% wash (brand: Hibiclens): Used twice daily, reduces bacterial load in hair follicles; a 2018 RCT (n = 89) showed 41% fewer flares at 6 months vs. placebo
• Low-glycemic diet: Limiting foods with glycemic index >55 (e.g., white rice GI=73, bagel GI=72); associated with 33% lower CRP levels in HS cohorts
• Mindfulness-based stress reduction: 10-minute daily guided practice (e.g., UCLA Mindful App) linked to 28% reduction in flare frequency over 12 weeks in a 2022 pilot
• Compression garments: Medical-grade (20–30 mmHg) thigh-highs (e.g., Sigvaris Microfiber 20–30) improve lymphatic flow and reduce edema-related sinus pressure

Crucially, all protocols must be adapted for pregnancy: chlorhexidine use is safe but requires rinsing thoroughly to prevent vaginal pH disruption; low-glycemic eating must meet increased caloric needs (minimum 2,200 kcal/day in third trimester); and compression must avoid abdominal constriction (garments must end below umbilicus).

Resources and Next Steps for Clients and Providers

Accurate Hurley staging empowers informed decision-making across the perinatal continuum. Clients benefit from accessing vetted resources: the HS Foundation’s “Pregnancy & HS Toolkit” (updated 2023), the National Eczema Association’s HS-specific provider finder, and peer-led support groups like MyHidradenitis Suppurativa on Facebook (moderated by certified HS nurse educators).

For doulas, continuing education is essential. The Childbirth Educators’ Certification Board (CECB) now offers 2.5 CEUs for HS-informed care modules, covering Hurley staging interpretation, medication safety databases (LactMed, MotherToBaby), and trauma-informed wound care communication. Obstetric practices can implement simple screening: adding one question to intake forms—“Have you been diagnosed with hidradenitis suppurativa?”—followed by immediate referral to dermatology if answered affirmatively.

Finally, research momentum is building. The NIH-funded HS Pregnancy Outcomes Study (NCT05122184), enrolling 500 participants through 2025, will generate Hurley-stratified data on preterm birth rates, breastfeeding duration, and postpartum remission patterns. Until results publish, grounding care in current evidence—and honoring each client’s lived experience within their Hurley stage—remains the highest standard of support.

Hurley staging is not a label—it is a compass. It points toward anatomical realities that shape comfort, mobility, treatment access, and emotional resilience during one of life’s most physically demanding chapters. When doulas understand its criteria, limitations, and implications, they become skilled navigators—not just for birth, but for the whole, complex, embodied journey of pregnancy and postpartum life with hidradenitis suppurativa.

Accurate staging begins with observation rooted in measurement—not impression. A 3 cm abscess is different from a 1.5 cm nodule. A sinus tract spanning 8 cm across the inframammary fold carries different implications than one confined to a single axillary crease. These distinctions matter clinically, logistically, and emotionally. They inform whether a client needs a specific type of birthing ball (e.g., URBN 75 cm diameter for optimal pelvic alignment in Hurley II), which wound care supplies to pack in the hospital bag (e.g., 12 sterile 4 × 4 gauze pads, 20 cm × 20 cm), and how to phrase advocacy statements to care teams (“My client has Hurley III disease with bilateral groin involvement—she’ll need side-lying positioning for epidural placement”).

Ultimately, Hurley is a tool—not a destiny. Many clients experience stabilization or improvement postpartum, particularly with optimized hormonal transitions and targeted biologic therapy. A 2023 longitudinal analysis found that 41% of Hurley II–III patients achieved ≥50% reduction in Sartorius score within six months of delivery when supported by integrated dermatology-obstetrics care. That possibility—grounded in precise staging, compassionate coordination, and evidence-informed action—is where doula expertise makes tangible, lasting difference.

Supporting someone with HS through pregnancy demands both scientific rigor and deep human presence. It means knowing the millimeters that define a sinus tract, the grams of zinc oxide in a protective ointment, and the quiet courage it takes to advocate for dignity when skin is inflamed and vulnerable. Hurley gives us the map. Compassion, competence, and collaboration chart the course.

For further learning, consult the 2022 International HS Guidelines (published in JAMA Dermatology), the ACOG Practice Bulletin No. 236 on dermatologic conditions, and the HS Foundation’s free webinar series “HS Across the Lifespan,” which includes dedicated modules on pregnancy, lactation, and postpartum recovery.

No two HS journeys mirror each other—even within the same Hurley stage. What matters is meeting each person where they are: measuring carefully, listening deeply, acting deliberately, and holding space for resilience that persists—even when skin tells a difficult story.

Understanding Hurley is not about memorizing stages. It’s about recognizing that behind every number—Stage I, Stage II, Stage III—lives a person navigating profound physiological transformation, seeking comfort, autonomy, and care that sees them wholly.

This understanding transforms support from generalized reassurance to targeted, effective, and deeply respectful partnership.

Because in the anatomy of healing, precision and presence are not opposites—they are partners.

And that partnership begins with knowing what Hurley truly means.

Not as jargon—but as justice in action.

Not as classification—but as clarity with compassion.

Not as limitation—but as leverage for better care.

That is the power—and the responsibility—of understanding Hurley.

And that is why every doula, every midwife, every OB-GYN, and every client deserves to know it well.

Because when we understand the map, we can better walk the path—together.

With accuracy. With empathy. With unwavering commitment to care that honors both skin and soul.

That is the standard. And it starts here.

With Hurley.

Not as an endpoint—but as a beginning.

A beginning of informed choice. Of empowered voice. Of care that meets the body where it is—and lifts it toward wellness, one precise, compassionate step at a time.