hid. suppurativa

Hidradenitis supperativa is a long term, inflammatory condition that affects the hair follicle. This creates abscesses (large lumps with pus), scarring and pain. It is usually found around the groin, bottom, breasts and armpits. The staging of condition development is the Hurley Staging System (1 being the lowest stage, 3 being the highest stages).

Epidemiology

According to the NHS, the condition affects 1 in 100 people however the numbers are still limited and some incidence rates are unknown
Affects more women that men [1]
According to HSdisease, about 93% of people with the condition are between 18-64 years old
In 2019, researchers in the United and Canada reported 2 peaks for the onset of symptoms:
- An early-onset group said HS symptoms began in their mid-teen years
- A late-onset group said HS symptoms began in their mid-40s [2]

Source: Mind The Gap

Hidradenitis suppurativa
Painful boil and abscess found in the armpit

Source: NHS

Hidradenitis suppurativa
Narrow channels (sinus tracts) form under the skin which can break the skin and lead to oozing of the wound

Pathophysiology [3]

Medical Students
- Follicular occlusion is the main trigger in hidradenitis suppurativa (HS), caused by keratosis and hyperplasia of follicular epithelium, leading to cyst formation.

The immune system plays a significant role in HS, and TNF-alpha inhibitors have shown promising responses in treating the condition.
Genetic investigations have revealed loss-of-function mutations in gamma-secretase subunits, potentially affecting proteins found in the body which may contribute to HS development.
Follicular occlusion is a consistent feature in the pathogenesis of HS, leading to hair follicle dilatation, rupture, and discharge of contents into the dermis, causing inflammation and abscess formation.
Proposed mechanisms for follicular occlusion in HS include deficiencies in the follicular skin immune system leading to microbial overgrowth and an overactive immune response to normal flora.

Patients
- Follicular occlusion is the main trigger in hidradenitis suppurativa (HS), caused by the excessive growth of the substance that creates hair and nails (keratin) and tissue growth of follicular epithelium (lining covering the follicles found in the skin) leading to cyst formation.

The immune system plays a significant role in the condition, and medicines that stop inflammation of the skin have shown promising responses in treating the condition.
Genetic investigations have revealed loss-of-function mutations in units that make up proteins, which may contribute to hidradenitis suppurativa development.
Blocking the follicles is a consistent feature in the origin of hidradenitis suppurativa, leading to hair follicle dilatation (making wider), rupture, and discharge of contents into the skin layers, causing inflammation and abscess (large lump) formation.
The reasons for this blockage of the follicles include deficiencies in the follicular skin immune system leading to microbial (related to microorganism) overgrowth and an overactive immune response to normal, harmless organisms present on the skin.

Hidradenitis suppurativa

Severe form of condition of the armpit causing thickened, discoloured, irritated skin with abscesses (large lumps)

Hidradenitis suppurativa

Scars, pits and blackheads formed with the condition found on the armpit

Causes [1]
- A lump forms as a result on blocked hair follicles
- Sex hormone involvement during puberty (associated symptoms are acne and increased hair growth- hirtuism)
- In rare cases, can be caused by Crohn’s disease (irritable bowel disease)

Risk factors [2]
- Family history
- Obesity
- Smoking
- Metabolic syndrome (eg. diabetes, high blood pressure, obesity)
- Thyroid diseases (eg. hyperthyroidism, cushing’s disease)
- Joint disease (eg. rheumatoid arthritis)
- Long term inflammation of the skin
- Pyoderma gangrenosum- an inflammatory skin disease that causes painful skin lumps or open sores (ulcers)
- Psoriases- red, scaly infection of the skin
- Vitiligo- condition that causes pathces of depigmentation
- Axial spondyloarthritis- arthritis in the spine and pelvic joints
- Inflammatory bowel disease
- Polycystic ovary syndrome- a condition that causes irregular periods and increased hormone (androgen) levels in the blood
- Squamous cell carcinoma- a common form of cancer

Presentations [1]
- Boil- like lumps
- Blackheads (open comedones)
- Cysts
- Scarring
- Pus filled lumps
- Fresh-coloured lumps
- Sinus tracks (channels formed in the skin that leak pus)
- Itchiness
- Pain

Source: DermNetNZ.org

Hidradenitis suppurativa
Stage 1- mild presentation with a single raised lesion

Source: NHS

Hidradenitis suppurativa
Fleshy lumps that grow on the surface of the skin

Investigations [4]
- History taking from symptoms and family history
- Examine the skin for boils/lumps in locations typically found on the body
- Potentially rule out differential diagnosis with blood and fluid samples from the lumps.

Differential diagnosis [5]
- Folliculitis (inflammation of the follicles)
- Furuncle/carbuncle- abscesses caused by the staphylococcal infection
- Giant comedones- type of cyst with a blackhead-like opening
- Can also be mistaken for severe forms of acne, Crohn’s disease and syphilis

Management [6]
- Medical Students
  - Categorisation of Hidradenitis suppurativa is necessary to determine what treatment is used and managed
    - Hurley Stage 1- Mild
      - Inflammatory nodule
      - No sinus tracts and scarring
        Topical clindamycin
        Intralesional corticosteroids
        Oral antibiotics
    - Hurley Stage 2- Moderate
      - Recurrent abscesses
      - Sinus tract formation
      - Scarring
        Longer course of oral antibiotics
        Drainage, unroofing or punch debridement
    - Hurley Stage 3- Severe
      - Affects many areas
      - Multiple sinus tracts
      - Scarring present
      - Abscesses present
        Infliximab
        Adalimumab
        Wide surgical excision
        Repair and grafting
  - Lifestyle changes:
    - Maintain good hygiene
    - Minimise trauma
    - Provide mental health support
    - Avoid diets with high levels of glucose (eg. white bread, chips, cakes)

Patients
- Categorisation of Hidradenitis suppurativa is necessary to determine what treatment is used and managed

Hurley Stage 1- Mild
- Inflammatory nodule (abnormal tissue growth)
- No sinus tracts and scarring
  - Topical clindamycin (antibiotic)
  - Intralesional corticosteroids (steroids applied within a lesion- area of skin damaged)
  - Oral antibiotics
Hurley Stage 2- Moderate
- Recurrent abscesses
- Sinus tract formation
- Scarring
  - Longer course of oral antibiotics
  - Drainage, unroofing or punch debridement (process of cleaning the wound and removing thickened skin, infected and dead skin)
Hurley Stage 3- Severe
- Affects many areas
- Multiple sinus tracts
- Scarring present
- Abscesses present
  - Infliximab (chemotherapy drug also used to help fight infections by substituting antibodies)
  - Adalimumab (medicine used to reduce swelling)
  - Wide surgical excision (removal of areas with suspected cancer using surgery), then repairment

Lifestyle changes:
- Maintain good hygiene
- Minimise trauma
- Provide mental health support
- Avoid diets with high levels of glucose (eg. white bread, chips, cakes)

Complications [7]
- Can affect the skin or the body with systemic complications
- Skin
  - Sinus tracts
  - Fistulae
  - Scarring
  - Contractures
  - Squamous cell carcinoma
  - Lymphedema (swelling of tissues due to fluid retention in the vessels that hold lymph)
- Systemic
  - Chronic (long term) pain
  - Systemic amyloidosis (disorder that is caused by amyloid being deposited in an organ in the body)
  - Anaemia (low blood cell count)

Source: DermNetNZ.org

Hidradenitis suppurativa
Stage 2 (Hurley ) presentation

Source: DermNetNZ.org

Hidradenitis suppurativa
Stage 3 (Hurley ) presentation

Myths behind hidraenitis suppurativa
- Hidradenitis suppurativa is contagious
- It can be spread through sexual intercourse
- It is a severe form of acne
- It is caused by poor hygiene
- It only impacts women [8]
- All patients with the condition will then experience a severe disease [9]

Questions you may want to ask your doctor
- What can I do to deal with a symptoms flare up (eg. leaking pus)?
- How long does treatment last/ take to be effective?
- How can I prevent complications for occuring?
- Will any underlying conditions I take medication for have to be changed with treatment for HS?