Hidradenitis Suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic inflammatory skin condition that causes painful, recurrent boil-like lumps in areas where skin rubs together. This debilitating condition primarily affects the armpits, groin, buttocks, and under the breasts, leading to significant physical discomfort and emotional distress. While not curable, various treatments can help manage symptoms and prevent progression.

Medical Disclaimer: This information is for educational purposes only and should not replace professional medical advice. If you suspect you have hidradenitis suppurativa, consult with a dermatologist for proper evaluation and treatment.

Overview

Hidradenitis suppurativa is a chronic, recurrent, debilitating skin condition that affects approximately 1-4% of the population worldwide. The condition typically begins after puberty and is characterized by painful, deep-seated nodules, abscesses, and sinus tracts in areas rich in apocrine glands. These areas include the axillae (armpits), inguinal region (groin), perianal area, and inframammary regions (under the breasts).

The pathophysiology of HS involves follicular occlusion, bacterial superinfection, and an abnormal immune response. Contrary to popular belief, HS is not caused by poor hygiene or contagious infections. Instead, it results from a complex interplay of genetic predisposition, hormonal factors, immune dysfunction, and environmental triggers. The condition follows a pattern of follicular hyperkeratinization, leading to keratin plug formation, follicular rupture, and subsequent inflammation.

HS is classified into three stages according to the Hurley staging system: Stage I involves isolated abscesses without scarring or sinus tracts; Stage II presents with recurrent abscesses with tract formation and scarring; and Stage III features diffuse involvement with multiple interconnected tracts and scarring. The condition significantly impacts quality of life, with patients often experiencing chronic pain, malodorous discharge, restricted mobility, and psychological distress.

The disease course is typically chronic and progressive, with periods of exacerbation and remission. Early diagnosis and treatment are crucial to prevent progression to advanced stages and minimize complications. Modern treatment approaches include topical and systemic therapies, biological agents, and surgical interventions, with the choice depending on disease severity and patient-specific factors.

Symptoms

The symptoms of hidradenitis suppurativa can vary significantly between individuals and may progress over time. The condition typically affects areas where skin rubs together and where apocrine glands are concentrated.

Primary Skin Manifestations

  • Skin swelling - painful, deep-seated nodules and bumps
  • Skin lesions - ranging from blackheads to large abscesses
  • Skin rash - inflammatory changes around affected areas
  • Skin growth - hypertrophic scarring and keloid formation
  • Painful nodules that may rupture and drain
  • Sinus tracts connecting lesions under the skin
  • Comedone-like lesions (blackheads) in affected areas

Associated Pain and Discomfort

  • Arm pain - when axillary areas are affected
  • Groin mass - painful swellings in the inguinal region
  • Chronic, throbbing pain in affected areas
  • Burning or stinging sensations
  • Tenderness and sensitivity to touch

Secondary Symptoms

  • Malodorous discharge from lesions
  • Staining of clothing from drainage
  • Restricted range of motion due to pain and scarring
  • Fatigue from chronic pain and inflammation
  • Sleep disturbances due to pain

Psychological and Social Symptoms

  • Depression and anxiety
  • Social isolation and withdrawal
  • Reduced self-esteem and body image issues
  • Impact on intimate relationships
  • Work or school absenteeism

Common Locations

  • Axillae (armpits): Most common site, affecting up to 90% of patients
  • Inguinal region: Groin and upper thighs
  • Perianal area: Around the anus and buttocks
  • Inframammary: Under the breasts in women
  • Other areas: Neck, waistline, and pubic region

Causes

The exact cause of hidradenitis suppurativa is not fully understood, but research has identified several contributing factors that work together to trigger and perpetuate the condition.

Primary Pathophysiological Mechanisms

  • Follicular occlusion: Blockage of hair follicles due to hyperkeratinization
  • Follicular rupture: Rupture of blocked follicles leads to inflammatory response
  • Bacterial colonization: Secondary bacterial infections worsen inflammation
  • Abnormal immune response: Dysregulated inflammatory pathways

Genetic Factors

  • Family history: 30-40% of patients have affected family members
  • Genetic mutations: Defects in γ-secretase complex genes (NCSTN, PSEN1, PSENEN)
  • Autosomal dominant inheritance: Pattern seen in familial cases
  • Genetic susceptibility: Predisposition to abnormal inflammatory responses

Hormonal Influences

  • Androgens: Male hormones may worsen the condition
  • Menstrual cycle: Symptoms often worsen before menstruation
  • Pregnancy: Can cause improvement or worsening of symptoms
  • Menopause: May lead to symptom improvement in some women

Environmental and Lifestyle Factors

  • Friction and trauma: Mechanical irritation from tight clothing
  • Heat and humidity: Excessive sweating can trigger flares
  • Stress: Emotional stress may worsen symptoms
  • Certain fabrics: Synthetic materials may increase irritation

Microbial Factors

  • Bacterial biofilms: Formation of protected bacterial communities
  • Specific bacteria: Staphylococcus, Streptococcus, and anaerobic bacteria
  • Altered microbiome: Changes in normal skin bacterial populations
  • Antimicrobial resistance: Development of resistant bacterial strains

Risk Factors

Several factors increase the likelihood of developing hidradenitis suppurativa or experiencing more severe symptoms. Understanding these risk factors helps in prevention and management strategies.

Demographic Risk Factors

  • Gender: Women are 2-3 times more likely to develop HS
  • Age: Typically begins after puberty, peak onset 20-30 years
  • Race: Higher prevalence in African Americans
  • Geographic location: More common in urban areas

Lifestyle Risk Factors

  • Smoking: 70-90% of HS patients are smokers
    • Nicotine affects immune function
    • Increases inflammation
    • Impairs wound healing
  • Obesity: Increased friction and sweating in skin folds
  • Sedentary lifestyle: May worsen obesity and friction
  • Poor diet: High glycemic index foods may worsen inflammation

Medical Risk Factors

  • Family history: 30-40% have affected relatives
  • Metabolic syndrome: Diabetes, insulin resistance
  • Inflammatory conditions: Crohn's disease, arthritis
  • Hormonal disorders: PCOS, thyroid dysfunction
  • Immunosuppression: Compromised immune system

Environmental Risk Factors

  • Hot, humid climate: Increased sweating and bacterial growth
  • Tight clothing: Increased friction and heat retention
  • Synthetic fabrics: Poor moisture wicking properties
  • Occupational factors: Jobs requiring tight uniforms or equipment

Exacerbating Factors

  • Stress: Physical and emotional stress
  • Hormonal changes: Menstruation, pregnancy
  • Certain medications: Lithium, some biologics
  • Mechanical trauma: Shaving, friction from clothing

Diagnosis

Diagnosing hidradenitis suppurativa can be challenging as it is often misdiagnosed as other conditions. Early and accurate diagnosis is crucial for effective treatment and preventing disease progression.

Clinical Diagnostic Criteria

The diagnosis of HS is primarily clinical, based on three main criteria:

  • Typical lesions: Painful or tender nodules, abscesses, draining sinuses, bridged scars
  • Typical locations: Axillae, inguinal region, perianal area, inframammary regions
  • Chronicity and recurrence: Two recurrences in 6 months

Medical History Assessment

  • Symptom timeline: Age of onset, duration, frequency of flares
  • Family history: Genetic predisposition evaluation
  • Smoking history: Important risk factor assessment
  • Previous treatments: Response to prior therapies
  • Associated conditions: Comorbidities and complications

Physical Examination

  • Lesion assessment: Type, size, location, and staging
  • Hurley staging: Classification of disease severity
  • Scarring evaluation: Extent of permanent damage
  • Range of motion: Functional impact assessment

Laboratory Tests

  • Bacterial culture: Identify specific pathogens for targeted therapy
  • Complete blood count: Assess for systemic inflammation
  • Inflammatory markers: CRP, ESR elevation
  • Glucose levels: Screen for diabetes

Imaging Studies

  • Ultrasound: Evaluate extent of sinus tracts and abscesses
  • MRI: Detailed assessment of complex cases
  • CT scan: Rule out complications in severe cases

Differential Diagnosis

  • Furunculosis: Simple bacterial skin infections
  • Lymphadenitis: Lymph node inflammation
  • Crohn's disease: Perianal manifestations
  • Pilonidal disease: Cysts in sacrococcygeal area
  • Bartholinitis: Bartholin gland infection

Staging Systems

Hurley Staging System

  • Stage I: Abscess formation without scarring or sinus tracts
  • Stage II: Recurrent abscesses with tract formation and scarring
  • Stage III: Diffuse involvement with multiple interconnected tracts

Treatment Options

Treatment of hidradenitis suppurativa requires a multimodal approach tailored to disease severity, location, and patient factors. The goal is to reduce inflammation, prevent new lesions, and improve quality of life.

Conservative Management

  • Lifestyle modifications: Weight loss, smoking cessation, loose clothing
  • Hygiene measures: Gentle cleansing with antiseptic washes
  • Warm compresses: For pain relief and drainage
  • Pain management: NSAIDs, topical analgesics

Topical Treatments

  • Clindamycin 1%: First-line topical antibiotic
  • Zinc pyrithione: Anti-inflammatory properties
  • Benzoyl peroxide: Antimicrobial and keratolytic effects
  • Topical corticosteroids: For acute inflammation
  • Resorcinol: Keratolytic and antiseptic properties

Systemic Antibiotic Therapy

First-line Antibiotics

  • Tetracycline class: Doxycycline, minocycline
  • Clindamycin: Often combined with rifampin
  • Combination therapy: Clindamycin + rifampin for severe cases

Alternative Antibiotics

  • Metronidazole: For anaerobic bacterial coverage
  • Erythromycin: Alternative for tetracycline-intolerant patients
  • Cephalexin: For staphylococcal infections

Biologic Therapies

  • Adalimumab (Humira): FDA-approved TNF-alpha inhibitor
    • First-line biologic for moderate to severe HS
    • Significant reduction in lesion count and pain
    • Requires regular monitoring for side effects
  • Infliximab: Alternative TNF-alpha inhibitor
  • Secukinumab: IL-17A inhibitor showing promise
  • Anakinra: IL-1 receptor antagonist

Other Systemic Therapies

  • Metformin: For patients with insulin resistance
  • Zinc supplementation: Anti-inflammatory effects
  • Hormonal therapy: Spironolactone for women
  • Retinoids: Acitretin for select cases

Surgical Interventions

Minor Procedures

  • Incision and drainage: For acute abscesses
  • Intralesional corticosteroids: Triamcinolone injections
  • Laser therapy: CO2 laser, Nd:YAG laser

Major Surgical Procedures

  • Wide local excision: Complete removal of affected tissue
  • Deroofing: Unroofing of sinus tracts
  • Skin grafting: For large defects after excision
  • Flap reconstruction: Complex reconstructive procedures

Treatment Algorithm by Stage

  • Stage I: Topical antibiotics, lifestyle modifications
  • Stage II: Systemic antibiotics, consider biologics
  • Stage III: Biologics, surgical intervention

Prevention

While hidradenitis suppurativa cannot be completely prevented due to its genetic component, various strategies can help reduce the risk of developing the condition or minimize flare-ups in those already affected.

Primary Prevention Strategies

  • Smoking cessation: Most important modifiable risk factor
  • Weight management: Maintain healthy BMI to reduce friction
  • Proper hygiene: Regular bathing with antibacterial soap
  • Appropriate clothing: Loose-fitting, breathable fabrics

Secondary Prevention (Reducing Flares)

  • Stress management: Relaxation techniques, counseling
  • Dietary modifications: Reduce high-glycemic foods, dairy
  • Gentle skincare: Avoid harsh scrubbing or irritants
  • Temperature control: Avoid excessive heat and humidity

Mechanical Prevention

  • Reduce friction: Use powder in skin folds
  • Proper shaving techniques: Electric razors, avoid close shaving
  • Cushioning: Soft padding for areas prone to pressure
  • Activity modification: Avoid prolonged sitting or tight clothing

Infection Prevention

  • Wound care: Proper cleaning and dressing of lesions
  • Antiseptic washes: Chlorhexidine or benzoyl peroxide
  • Early treatment: Address new lesions promptly
  • Antibiotic prophylaxis: In select high-risk situations

When to See a Doctor

Seek immediate emergency care for:

  • Signs of severe systemic infection: high fever, chills, confusion
  • Rapidly spreading redness or streaking
  • Severe pain that interferes with daily activities
  • Large abscesses requiring drainage
  • Signs of sepsis or blood poisoning

Schedule urgent appointment for:

  • New or worsening skin swelling in typical areas
  • Persistent or recurrent skin lesions
  • Increasing arm pain or mobility restrictions
  • Signs of secondary bacterial infection
  • Failure to respond to current treatment

Routine consultation recommended for:

  • Recurrent boil-like lesions in typical areas
  • Family history of HS with concerning symptoms
  • Chronic skin rash in friction areas
  • Impact on quality of life or daily activities
  • Need for ongoing management and monitoring

Related Conditions

References

  1. Alikhan A, Lynch PJ, Eisen DB. Hidradenitis suppurativa: a comprehensive review. J Am Acad Dermatol. 2009;60(4):539-561.
  2. Zouboulia H, Bechara FG, Dickinson-Blok JL, et al. Hidradenitis suppurativa/acne inversa: a practical framework for treatment optimization - systematic review and recommendations from the HS ALLIANCE working group. J Eur Acad Dermatol Venereol. 2019;33(1):19-31.
  3. Kimball AB, Okun MM, Williams DA, et al. Two Phase 3 Trials of Adalimumab for Hidradenitis Suppurativa. N Engl J Med. 2016;375(5):422-434.
  4. Garg A, Kirby JS, Lavian J, Lin G, Strunk A. Sex- and age-adjusted population analysis of prevalence estimates for hidradenitis suppurativa in the United States. JAMA Dermatol. 2017;153(8):760-764.
  5. Sabat R, Jemec GBE, Matusiak Ł, Kimball AB, Prens E, Wolk K. Hidradenitis suppurativa. Nat Rev Dis Primers. 2020;6(1):18.