Hidradenitis Suppurativa: Advanced MRI Imaging, Pathophysiology, Diagnosis, and Cutting-Edge Treatment Strategies – A Comprehensive Case-Based Review

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Keywords: Hidradenitis Suppurativa, MRI imaging, chronic inflammatory skin disease, diagnostic imaging, differential diagnosis, treatment strategies, prognosis

Abstract

Hidradenitis Suppurativa (HS) is a debilitating, chronic, and recurrent inflammatory skin disease characterized by painful nodules, abscess formation, sinus tract development, and irreversible scarring. While commonly affecting intertriginous areas such as the axillae and groin, atypical involvement of the nape of the neck remains exceedingly rare and often leads to delayed diagnosis. This comprehensive review integrates a real clinical case of nape Hidradenitis Suppurativa with cutting-edge literature, advanced MRI imaging findings, and evidence-based treatment strategies. We provide an in-depth discussion of the pathophysiology, epidemiology, clinical manifestations, imaging characteristics, differential diagnosis, diagnostic workflow, therapeutic interventions, and prognosis, supplemented by detailed MRI interpretations, quizzes, and references to the most influential contemporary research.

1. Introduction: Understanding Hidradenitis Suppurativa

Hidradenitis Suppurativa (HS), also known as acne inversa, is a chronic, inflammatory, follicular occlusive disease that significantly impairs quality of life. The condition is hallmarked by recurrent painful nodules, abscesses, sinus tracts, and fibrotic scarring, often leading to disfigurement and psychosocial distress.

Historically regarded as a disorder of the apocrine sweat glands, modern evidence now clearly establishes HS as a primary disease of the follicular unit, driven by follicular occlusion, immune dysregulation, and chronic inflammation.

2. Epidemiology of Hidradenitis Suppurativa

  • Global prevalence: 0.1–1%

  • Female-to-male ratio: 3:1

  • Typical age of onset: 20–40 years

  • Risk factors:

    • Obesity

    • Smoking

    • Genetic predisposition

    • Metabolic syndrome

    • Mechanical friction

    • Hormonal influences

Rare Anatomical Locations

Most HS lesions involve:

  • Axillae

  • Groin

  • Perineal region

  • Gluteal cleft

  • Inframammary folds

Nape involvement accounts for <1% of cases, making this anatomical site extremely rare and diagnostically challenging.

3. Clinical Case Summary

Patient Profile

  • Age: 41 years

  • Sex: Male

  • Chief Complaint:

    • Progressive posterior neck swelling for 2 years

    • Intermittent purulent discharge

    • Refractory to repeated antibiotic therapy

Clinical Course

The patient presented with chronic swelling and purulent discharge from the nape region, associated with pain and recurrent inflammation. Repeated antibiotic therapy produced only transient improvement. MRI evaluation was subsequently performed to determine lesion extent and guide therapeutic strategy.

4. MRI Imaging Findings and Radiological Interpretation

Figure 1. Axial T2-weighted MRI

Thickening of the skin and subcutaneous tissue beneath a posterior cervical skin marker, showing serpiginous sinus tracts with high T2 signal intensity and surrounding low-signal fibrotic tissue, indicating chronic inflammatory infiltration and abscess formation.

Figure 2. Sagittal T2-weighted MRI

Caption: Lobulated soft tissue mass confined to superficial layers of the posterior neck without deep muscular invasion, suggesting localized disease extent.

Figure 3. Axial STIR MRI

Caption: Hyperintense sinus tracts and microabscesses demonstrated on STIR imaging, highlighting active inflammatory components.


Figure 4. Sagittal T2-weighted MRI

Caption: Extensive skin thickening, fibrosis, and sinus tract formation consistent with advanced chronic-stage hidradenitis suppurativa.

5. Comprehensive Imaging Interpretation

The MRI findings demonstrate classical radiologic features of advanced HS:

MRI FindingClinical Significance
Skin thickening  Chronic inflammation
Subcutaneous infiltration  Active inflammatory disease
Serpiginous sinus tracts  Chronic recurrent abscess formation
High T2 signal fluid collections  Active abscesses
Low T2 signal fibrosis    Chronic scarring
No deep muscular involvement  Localized disease

Final Imaging Diagnosis:
Hidradenitis Suppurativa involving the nape region (HS-nape)

6. Pathophysiology of Hidradenitis Suppurativa

Modern understanding recognizes HS as a follicular occlusion disorder, not a sweat gland disease.

Stepwise Pathogenesis

  1. Follicular hyperkeratosis and occlusion

  2. Follicular dilation and rupture

  3. Release of keratin and bacteria into the dermis

  4. Intense immune response

  5. Chronic inflammation → abscess → sinus tract formation → fibrosis

Molecular Pathways

Key inflammatory mediators:

  • TNF-α

  • IL-1β

  • IL-17

  • IL-23

  • IFN-γ

These cytokines drive persistent inflammation, tissue destruction, and impaired healing.

7. Clinical Presentation

Patients typically present with:

  • Painful inflammatory nodules

  • Recurrent abscesses

  • Chronic purulent discharge

  • Malodorous drainage

  • Sinus tract formation

  • Progressive scarring

  • Restricted mobility

  • Psychological distress

Atypical presentations, such as nape involvement, often delay diagnosis.

8. Differential Diagnosis

DiseaseDistinguishing Features
Epidermal inclusion cyst   Solitary lesion, no sinus tracts
Cellulitis   Acute onset, diffuse inflammation
Lipoma   Non-inflammatory, soft mass
Tuberculous abscess   Systemic symptoms, TB markers
Scleredema of Buschke   Diffuse thickening, no abscess

9. Diagnostic Approach

Clinical Diagnosis

  • Typical lesions

  • Typical locations

  • Chronicity and recurrence

Role of MRI

MRI is the gold standard imaging modality for:

  • Mapping disease extent

  • Detecting occult sinus tracts

  • Differentiating fibrosis from active inflammation

  • Surgical planning

10. Evidence-Based Treatment Strategies

A. Medical Therapy

1. Antibiotics

  • Clindamycin + Rifampicin combination

  • Anti-inflammatory effect

  • Moderate efficacy

2. Biologic Therapy

Adalimumab (TNF-α inhibitor)

  • Only FDA-approved biologic for HS

  • Demonstrates a significant reduction in lesion count and severity

3. Adjunctive Therapies

  • Intralesional steroids

  • Hormonal modulation

  • Retinoids

B. Surgical Management

  • Wide excision of the involved tissue

  • Lowest recurrence rate

  • Essential in advanced disease

Case Plan:
Failure of medical therapy → definitive surgical excision recommended

11. Prognosis

Disease StagePrognosis
Early diagnosisExcellent
Moderate diseaseVariable
Advanced diseaseChronic, recurrent

Biologic therapies have revolutionized long-term outcomes, reducing flare frequency and disease progression.

12. Associated Systemic Conditions

HS and Spondyloarthritis

MRI findings revealed cervical spine changes consistent with ankylosing spondylitis, highlighting the known association between HS and inflammatory arthropathies.

Shared inflammatory pathways:

  • TNF-α

  • IL-17

Quiz

Question 1. A 41-year-old male presents with chronic posterior neck swelling and purulent discharge. MRI shows serpiginous sinus tracts and T2 hyperintense abscesses. What is the most likely diagnosis?

A) Epidermal cyst
B) Cellulitis
C) Lipoma
D) Hidradenitis Suppurativa

Answer: D. Explanation: Chronic inflammation, sinus tracts, abscess formation, and recurrence strongly indicate HS.

Question 2. What is the primary pathophysiological mechanism underlying HS?

A) Apocrine gland infection
B) Lymphatic obstruction
C) Follicular occlusion
D) Vasculitis

Answer: C. Explanation: HS is fundamentally a follicular occlusion disorder.

Question 3. Which biologic agent is FDA-approved for moderate-to-severe HS?

A) Infliximab
B) Adalimumab
C) Tocilizumab
D) Rituximab

Answer: B. Explanation: Adalimumab is currently the only FDA-approved biologic therapy for HS.

Conclusion

Hidradenitis Suppurativa of the nape is a rare yet clinically significant variant of HS. Due to its atypical location, diagnosis is often delayed, resulting in advanced disease at presentation. MRI plays a pivotal role in accurate disease mapping, treatment planning, and prognosis assessment. Early diagnosis, multidisciplinary care, and biologic therapies represent the cornerstone of modern HS management.

References

[1] G. B. E. Jemec, “Clinical practice: Hidradenitis suppurativa,” New England Journal of Medicine, vol. 366, no. 2, pp. 158–164, 2012.

[2] C. C. Zouboulis et al., “Hidradenitis suppurativa/acne inversa: a practical framework for treatment optimization,” Journal of the European Academy of Dermatology and Venereology, vol. 33, no. 1, pp. 19–31, 2019.

[3] A. Kouris et al., “Quality of life and psychosocial implications in patients with hidradenitis suppurativa,” Dermatology, vol. 232, pp. 687–691, 2016.

[4] A. Kimball et al., “Two phase 3 trials of adalimumab for hidradenitis suppurativa,” New England Journal of Medicine, vol. 375, pp. 422–434, 2016.

[5] H. H. van der Zee and G. B. Jemec, “Imaging in hidradenitis suppurativa,” Dermatologic Clinics, vol. 34, no. 1, pp. 59–68, 2016.

[6] T. Tzellos et al., “Association of hidradenitis suppurativa with inflammatory arthritis,” JAMA Dermatology, vol. 151, no. 10, pp. 1131–1136, 2015.

[7] J. Alikhan et al., “North American clinical management guidelines for hidradenitis suppurativa,” Journal of the American Academy of Dermatology, vol. 81, no. 1, pp. 76–90, 2019.

While this column draws on case studies and existing literature, it is not a substitute for professional medical advice. Please consult your physician for clinical guidance.

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