Hidradenitis suppurativa

Question 1

What is hidradenitis suppurativa?

Answer 1

HS is a chronic inflammatory skin condition in the INTERTRIGINOUS AREAS (where two opposing surfaces touch, eg armpits, groin, under breasts, buttocks)

Causes abscesses, fistulas and inflammation which can result in chronic scaring

Associated with obesity, smoking, androgen dysfunction and metabolic syndrome.

Variable course. Treatment is effective but most important is life-style based.

Question 2

Epidemiology and aetiology of hidradenitis suppurativa?

Answer 2

• 1% of population
• 30% have strong FHx
• F>M 3:1
• not before puberty
• mean age onset is 21
• rare in asians, common in caucasians and afro-caribbeans

Associated:

• obesity 60%
• acne 50%
• hyperlipidaemia 45%
• depression
• insulin resistance
• pilonidal sinus
• PCOS
• T2DM
• hypertension
• pyoderma gangrenous
• Crohn’s disease
• spondyloarthropathy
• Down’s syndrome

Question 3

What is the pathopysiology is hidradenitis suppurativa?

Answer 3

Follicular occlusion occurs (unknown reason) followed by strong inflammatory reaction (strength depends of associated factors! esp smoking, obesity, glucose metabolism etc)

Microbiome thought to be linked.

Untreated it can be progressive

Question 4

Diagnosis of hidradenitis suppurativa?
Staging?
Investigations?

Answer 4

Clinical when all 3 of:

• deep, painful skin nodules
• intertiginous areas
• chronic and recurring

severity classified on Hurley Staging system.

Hurley 1 - abscess formations (no fistula or scarring)

Hurley 2 - recurrent abscesses with sinus to surface and scarring

Hurley 3 - multiple tracts and abscesses

Investigations:

• blood glucose for associated diabetes
• swab MC+S (usually negative)

Question 5

Complications of hidradenitis suppurativa?

Answer 5

• scarring (chronic can increase risk of SSC formation)
• lymphoedema (from destruction of lymphatic drainage structures)
• fistula formation to other organs (rare, urethra, bladder, rectum)
• arthropathy

Psychological

• pain, appearance, smell
• sexual dysfunction and social isolation, depression
• HS support groups

Question 6

Management of HS?

Answer 6

MEDICAL:
Hurley 1
- topical; CHLOHEXIDINE wash; CLINDAMYCIN 2%cream
- DOXYCYCLINE 100mg OD or MINOCYCLIN 50mg BD 3-4 months.

Hurley 2 (recurrent with sinus and scars)

• oral CLINDAMYCIN 300mg BD plus RIFAMPACIN 600mg
• 10 weeks

Hurley 3

• biologic therapy eg ADALIMUMAB SC injection (anti TNF)
• oral steroids

(Abx effective due to immunomodulating and anti-inflammatory effects, not microbial)

LIFESTYLE:
- stop smoking, lose weight, loose clothing, psychological support
COMORBIDS:
- monitor insulin and diabetes
- check for PCOS
- check lipids

SURGICAL:

• acute: local incision and drainage, high recurrence
• longterm: wide local excision with skin graft if very severe
• surgery only way to solve scarring and fistulae

LASER - destroy pilosebaceous glands, variable results

PAIN
- paracetamol, NSAIDs, ?opioids, steroids can help with inflammatory pain