Hidradenitis Suppurativa
Hidradenitis suppurativa, also known as acne inversa, is a chronic inflammatory follicular occlusive disorder affecting intertriginous areas such as the axillae and groin.
This updated UKMLA guide to hidradenitis suppurativa is based on PCDS guidance, which covers causes, risk factors, symptoms, diagnosis and management.
Causes and Risk Factors
The exact underlying cause is unclear
- Underlying mechanism: follicular plugging obstructs the apocrine gland ducts → accumulation of secretions causes follicular epithelium swelling and eventually ruptures → bacterial infection and sinus tract formation between abscesses
Risk factors:
- Obesity, metabolic syndrome, type II diabetes
- Cardiovascular diseases
- Smoking
- Heat and sweating
- Stress
Hidradenitis suppurativa is thought to be influenced by hormones:
- More common in females
- More common during reproductive age (uncommon before puberty and after menopause)
- Concurrent PCOS, hirsutism, and acne are common
Clinical Features and Diagnosis
| Locations | Affects intertriginous / flexural areas:
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| Early features |
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| Progression / late features |
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Hidradenitis suppurativa increases risk of squamous cell carcinoma, esp. in >50 y/o males with buttock disease.
Severity Classification
The severity and extent can be assessed using the Hurley scale:
| Severity | Simplified version | Full description |
|---|---|---|
| Mild (stage 1) | Small amount of abscesses / nodules without sinus tracts or scarring |
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| Moderate (stage 2) | Recurrent abscesses with sinus tracts and scarring |
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| Severe (stage 3) | Multiple abscesses with interconnected sinus tracts |
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Management
Acute Flare Management
Most cases are non-infective (sterile), consider
- Intra-lesional steroid injection (e.g. triamcinolone acetonide), or
- Oral prednisolone (short course)
If an infective flare is suspected:
- Avoid corticosteroids
- Treat with flucloxacillin (penicillin allergic: clarithromycin)
- Consider incision and drainage for tense and fluctuant abscesses
Long-Term Management
| General / conservative management | ALL patients:
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| Pharmacological management | 1st line (3-month trial):
2nd line:
3rd line (secondary care options):
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| Special considerations | In patients with PCOS and/or pre-menstrual flares, consider
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