chilblains

Chilblains, also known as perniosis, are areas of the skin (seen as patches) which are small and itchy. They appear after exposure to cold, damp, non-freezing conditions which trigger inflammation of the blood vessels found in the extremities.

Epidemiology

According to Scleroderma and Reynaud’s UK, chilblains affect 1 in 10 people in the UK [1]
According to the JAMA network, the overall incidence rate of chilblains was 11.5 per 100, 000 person-years (takes into account both the number of people in the study and the amount of time each person spends in the study) from Jan 2016 to Feb 2020
Females had a higher incidence of chilblains than males before and during the pandemic [2]
Data is limited by patterns that have found that symptoms commonly begin in early winter and resolve by spring [3]

Source: DermNetNZ.org

Chilblains
Redness and sores developed on the fingers

Source: Brown Skin Matters

Chilblains
The symptoms of chilblains are less obvious on skin of colour

Pathophysiology [4]

Medical Student
- Largely unknown but is associated with an abnormal response of the blood vessels to certain conditions
- Caused by cold, damp conditions affecting the small blood vessels in the body, most likely extremities like hands and feet
- This results in vessel damage to the capillary beds in the skin, leading to blood perfusion to the site affected.
- Causes erythematous, pruritis and inflammation
Patients
- Largely unknown causes but associated with temperatures and the response of blood vessels
- Caused by cold, damp conditions affecting the small blood vessels in the body, most likely areas like hands and feet
- This results in vessel damage in the skin, leading to blood entering the site of the skin affected.
- Causes redness, itching and inflammation

Causes [5]

Damp, cold weather
Abnormal reaction to the cold

Risk factors [6]
- Poor circulation
- Family history
- Poor diet
- Low BMI
- Raynaud’s syndrome- lack of circulation affecting the extremities most often
- Regular exposure to certain conditions eg. damp, cold
- Lupus- conditions where the body tissue swells
- Smoking
Presentations [7]
- Redness (erythema)
- Swelling
- Pain
- Itchiness (pruritis)
- Blistering/ulcers forming may occur in severe cases
- Patching pattern on the skin

Source: NHS

Chilblains
Skin can feel itchy and burning

Source: NHS

Chilblains
Toes may become red, purple or swollen. May be harder to see discolouration on darker skin

Investigations [8]

History taking about exposure to causative conditions, symptoms, risk factors, previous experience with chilblains and associated symptoms.
Clinical exam of the person; focusing on skin changes, peripheral pulses, diabetes and an assessment of underlying conditions such as lupus and Raynaud’s syndrome.

Differential diagnosis [9]
- Dyshidrotic dermatitis- recurrent itchy blisters affecting the extremities
- Raynaud’s phenomenon- lack of circulation in the extremities
- COVID toes
- Psychostimulant medication associated with blue discolouration of the toes
- Erythema multiforme minor- reaction of the body that causes lesions
- Lupus chilblains
- First-degree burns
- Frostbite
- Bruising secondary to trauma
- Antiphospholipid antibody syndrome- immune reaction of the body that increases the risk of clotting of the blood.

Source: Primary Care Dermatology Society

Chilblains
Brown crusting and redness of the toes

Source: Brown Skin Matters

Chilblains
In the skin of colour, presentations can be harder to notice and diagnose

Management [8]

Students
- If thought to be due to underlying conditions, refer to a specialist dependent on the condition present
- If the cause is idiopathic
  - Reassurance in the self-resolving nature of the condition; most likely to recover after 2-3 weeks
  - Advice on self-care management
    - Gradually warming the skin with the avoidance of direct heat to the affected site
    - Avoidance of smoking
    - Advise lifestyle changes that place a risk of recurrence of chilblains
      - Avoiding cold, damp conditions
      - Wearing appropriate clothing for cold, damp conditions eg. gloves, socks
      - Avoid stimulants that cause blood vessel constriction such as caffeine
      - Avoid drug-focused management
- If chilblains are severe, chronic and don’t respond to initial treatment
  - Reconsider the possibility of underlying conditions and refer if appropriate
- If no underlying cause is identified and no contraindications are noted; consider prescribing the calcium channel blocker- nifedipine (modified release)
  - Titrate up to 60mg maximum
  - Do not prescribe to under 18s or pregnant/breastfeeding women
  - Advise stopping drug if not effective
- Advise lifestyle and self-care techniques during drug treatment
Patients
- If thought to be due to underlying conditions, refer to a doctor that specialises in the field specific to the condition is advised
- If the cause is not due to a specific/ obvious condition
  - Reassurance in self-resolving nature of the condition; most likely to recover after 2-3 weeks
  - Advice self-care management
    - Gradually warming the skin with the avoidance of direct heat to the affected site
    - Avoidance of smoking
    - Advise lifestyle changes that place a risk of recurrence of chilblains
      - Avoiding cold, damp conditions
      - Wearing appropriate clothing for cold, damp conditions eg. gloves, socks
      - Avoid substances that cause blood vessel narrowing such as caffeine
- If chilblains are severe, long term and don’t respond to initial treatment
  - Reconsider the possibility of underlying conditions and refer if appropriate
- If no underlying cause is identified and no warning/harm from taking the drug is noted; consider prescribing the calcium channel blocker (stop calcium from entering the heart and arteries)- nifedipine
  - Prescribe up to 60mg maximum
  - Do not prescribe to under 18s or pregnant/breastfeeding women
  - Advise stopping drug if not effective
- Advise lifestyle and self-care techniques during drug treatment

Complications

Infections caused by blistering or scratched skin
Ulcers forming
Permanent discolouration of the skin affected [6]
Scarring of the skin due to repeated exposure to the cold [10]

Source: DermNetNZ.org

Chilblains
Can turn the skin red and may cause a burning or stinging sensation

Source: Primary Care Dermatology Society

Chilblains
Toes can become red and purple

Myths behind Chilblains
- Chilblains are always non-severe
- Chilblains are caused by freezing conditions
- Chilblains are linked to vitamin deficiencies