What is the diagnosis and treatment for an adult patient with a history of skin issues and suspected hidradenitis suppurativa?

Hidradenitis Suppurativa: Comprehensive Overview

Definition and Diagnosis

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent skin disease of the hair follicle that develops after puberty, presenting with painful inflammatory nodules, abscesses, comedones, scarring, and tunneling sinus tracts in intertriginous areas—most commonly the axillae, inguinal, and anogenital regions. 1

Diagnostic Criteria

Diagnosis relies on three clinical findings 1:

• Typical HS lesions: painful inflammatory nodules, abscesses, draining sinus tracts, comedones, and scarring 1
• Predilection for intertriginous sites: axillae, groin, anogenital regions, inframammary areas, buttocks 1
• Recurrence: chronic, relapsing course 1

Disease Severity Classification

Use the Hurley staging system in clinical practice, as it is simple and directly guides therapeutic decisions 1:

• Hurley Stage I: Recurrent nodules and abscesses with minimal scarring, no sinus tracts 1
• Hurley Stage II: One or limited number of sinuses/fistulas and scarring within a body region 1
• Hurley Stage III: Multiple or extensive sinuses/fistulas and scarring 1

Assess treatment response using inflammatory lesion counts (abscesses and inflammatory nodules), pain Visual Analog Scale (VAS), and Dermatology Life Quality Index (DLQI) at baseline and 12 weeks 1. The Hidradenitis Suppurativa Clinical Response (HiSCR)—defined as ≥50% reduction in abscess/nodule count with no increase in abscesses or draining fistulas—is the most validated measure for research settings 1, 2.

Epidemiology

HS affects approximately 1% of the general population, with prevalence ranging from 0.1% to 2% depending on the study methodology 1. The disease predominantly affects 1:

• Age: Third and fourth decades of life (mean age 20-40 years) 1
• Sex: Female predominance (though some studies show equal distribution) 1
• Race: Higher prevalence in patients of African descent 1
• Socioeconomic status: Lower socioeconomic groups 1

The mean incidence is 6.0 per 100,000 person-years, with a two-fold increase observed between 1968 and 2008 1.

Pathogenesis

HS pathogenesis is complex, involving follicular occlusion, dysregulation of innate and adaptive immunity, and genetic susceptibility 1, 3:

• Genetic factors: γ-secretase/Notch pathway mutations 1
• Innate immunity: Macrophages, neutrophils, IL-1β, TNF-α, granulocyte colony-stimulating factor 1, 3
• Adaptive immunity: Type 1 and type 17 helper T cells, IL-17, IFN-γ 1, 3
• B-cell mechanisms: Dermal tertiary lymphatic structures and autoantibodies 3

Chronic inflammation leads to irreversible skin damage with tunnel formation and morbid scarring 3.

Clinical Impact

HS significantly reduces quality of life due to physical, emotional, and psychological consequences, including chronic pain, drainage, scarring, and disfigurement 1, 4. The disease presents a significant financial burden to society through hospitalization and emergency department costs 1.

Comorbidities

Screen all patients for the following comorbidities 5:

• Metabolic: Diabetes, hypertension, hyperlipidemia, obesity 5, 3
• Psychiatric: Depression and anxiety 5
• Inflammatory: Inflammatory bowel disease, inflammatory arthritis 5, 3
• Cardiovascular risk factors: Measure blood pressure, lipids, HbA1c 5

Treatment Algorithm by Disease Severity

Hurley Stage I (Mild Disease)

First-line therapy: Topical clindamycin 1% solution or gel applied twice daily to all affected areas for 12 weeks 6, 5, 2:

• Combine with benzoyl peroxide wash or chlorhexidine 4% wash daily to reduce Staphylococcus aureus resistance risk 5
• Alternative skin cleansers include zinc pyrithione 5

Adjunctive therapy for inflamed lesions: Intralesional triamcinolone 10 mg/mL (0.2-2.0 mL) provides rapid symptom relief within 1 day, with significant reduction in erythema, edema, suppuration, and pain 5.

Alternative topical option: Resorcinol 15% cream reduces pain and duration of abscesses, though irritant dermatitis is a common side effect 5.

If topical therapy fails after 12 weeks, escalate to oral tetracyclines 5:

• Doxycycline 100 mg once or twice daily for 12 weeks 5
• Lymecycline 408 mg once or twice daily for 12 weeks 5
• Tetracycline 500 mg twice daily for up to 4 months 6, 5

Hurley Stage II (Moderate Disease)

First-line therapy: Clindamycin 300 mg orally twice daily PLUS rifampicin 300-600 mg orally once or twice daily for 10-12 weeks 6, 5:

• This combination achieves response rates of 71-93% in systematic reviews, far superior to tetracycline monotherapy (30% abscess reduction) 6, 5
• Treatment can be repeated intermittently as monotherapy or as adjuvant therapy in severe disease 5

Do NOT use doxycycline or tetracycline monotherapy as first-line for Hurley Stage II with abscesses or deep inflammatory nodules, as these have minimal effect on these lesions 5.

Combine with intralesional triamcinolone 10 mg/mL for acutely inflamed nodules 5.

If no clinical response after 12 weeks, escalate to adalimumab 6, 5.

Hurley Stage III (Severe Disease)

First-line biologic therapy: Adalimumab (FDA-approved for moderate-to-severe HS in patients ≥12 years old) 6, 5, 7:

Adult dosing 6, 5, 7:

• Day 1: 160 mg (given in one day or split over two consecutive days)
• Day 15: 80 mg
• Day 29 and subsequent doses: 40 mg weekly (NOT every other week—this dosing is ineffective for HS) 5

Adolescent dosing (12 years and older) 7:

• 30-60 kg: Day 1: 80 mg; Day 8 and subsequent doses: 40 mg every other week
• ≥60 kg: Day 1: 160 mg (single dose or split); Day 15: 80 mg; Day 29 and subsequent doses: 40 mg weekly or 80 mg every other week

Adalimumab achieves HiSCR response rates of 42-59% at week 12 5, 2. If no clinical response after 16 weeks, consider alternative treatments 2.

Second-line biologic options after adalimumab failure 5:

• Infliximab: 5 mg/kg at weeks 0,2,6, then every 2 months 6, 5
• Secukinumab: Response rates of 64.5-71.4% in adalimumab-failure patients at 16-52 weeks 5
• Ustekinumab: Alternative IL-12/IL-23 inhibitor 5

Alternative Systemic Therapies

For patients unresponsive to adalimumab or when biologics are contraindicated 5:

• Acitretin: 0.3-0.5 mg/kg/day in males and non-fertile females (teratogenicity concern) 5, 8
• Dapsone: Start at 50 mg daily, titrate up to 200 mg daily 5
• Ertapenem: 1g daily IV for 6 weeks as rescue therapy or during surgical planning 5

Oral corticosteroids (prednisone) are reserved ONLY for acute, widespread flares while awaiting response to definitive therapies—NOT for routine or long-term management 5. No randomized controlled trials support their use in HS 5.

Surgical Interventions

Surgery is often necessary for lasting cure, especially in advanced disease with sinus tracts and scarring 6, 5, 2:

• Deroofing: For recurrent nodules and tunnels 6, 5
• Radical surgical excision: For extensive disease (Hurley Stage III) with sinus tracts and scarring 6, 5
• Wound closure options: Secondary intention healing, skin grafts, or flaps (e.g., TDAP flap) 5

Combining adalimumab with surgery results in greater clinical effectiveness than adalimumab monotherapy 5.

Do NOT offer cryotherapy or microwave ablation during the acute phase 5.

Mandatory Adjunctive Measures for All Patients

Regardless of disease severity or treatment choice, address the following 5, 2:

• Smoking cessation referral: Tobacco use is associated with worse outcomes 5, 2
• Weight management referral if BMI elevated: Obesity is associated with increased HS severity and is a modifiable risk factor 6, 2
• Pain management: NSAIDs for symptomatic relief 5, 2
• Appropriate wound dressings for draining lesions 5, 2
• Screen for depression/anxiety 5, 2
• Screen for cardiovascular risk factors: Blood pressure, lipids, HbA1c 5, 2

Treatment Monitoring and Reassessment

Reassess all patients at 12 weeks using 5:

• Pain VAS score 5
• Inflammatory lesion count (abscesses and inflammatory nodules) 5
• Number of flares 5
• Quality of life (DLQI) 5

Consider treatment breaks after antibiotic courses to assess need for ongoing therapy and limit antimicrobial resistance 5.

Special Population Considerations

Pediatric Patients

• Ages 6 years and older with Crohn's disease-like HS: Weight-based dosing of adalimumab 7
• Ages 12 years and older with moderate-to-severe HS: FDA-approved adalimumab dosing based on weight 7
• Ages ≥8 years requiring systemic antibiotics: Doxycycline 100 mg once or twice daily 5

Pregnancy and Breastfeeding

For breastfeeding patients, use amoxicillin/clavulanic acid, erythromycin, azithromycin, or metronidazole; limit doxycycline to ≤3 weeks without repeating courses 5.

HIV-Positive Patients

Avoid rifampicin due to drug interactions with certain HIV therapies; use doxycycline for added prophylactic benefit against bacterial STIs 5.

Treatments with Insufficient Evidence

The following therapies lack sufficient evidence for recommendation 5:

Alitretinoin, anakinra, apremilast, atorvastatin, azathioprine, ciclosporin, colchicine, cyproterone, finasteride, fumaric acid esters, hydrocortisone, hyperbaric oxygen therapy, intravenous antibiotics (except ertapenem), isoniazid, laser and photodynamic therapies, methotrexate, oral prednisolone (except acute flares), oral zinc, phototherapy, photochemotherapy, radiotherapy, spironolactone, staphage lysate, tolmetin sodium 5.

Do NOT offer isotretinoin unless there are concomitant moderate-to-severe acneiform lesions of the face or trunk 5.

Do NOT offer etanercept for moderate-to-severe HS, as it is ineffective 5.

Critical Pitfalls to Avoid

• Do NOT use adalimumab 40 mg every other week for HS—this dosing is ineffective; use 40 mg weekly 5
• Do NOT use topical clindamycin alone for Hurley Stage II—it only reduces superficial pustules, not inflammatory nodules or abscesses 5
• Do NOT continue doxycycline beyond 4 months without reassessment—prolonged use increases antimicrobial resistance risk 5
• Do NOT delay referral to dermatology for Hurley Stage III disease 5
• Do NOT use oral corticosteroids for long-term management—reserve only for acute flares 5

Diagnostic Testing Limitations

Microbiologic screening has limited utility in HS, as mixed normal flora and skin commensals are the main bacteria cultured from suppurative discharge 1. Culture is not routinely recommended unless there is concern for secondary infection or treatment failure 1.