What is winter itch?
Winter itch, also known as pruritus hiemalis, is a type of subclinical dermatitis, that affects individuals during cold weather.
Clinical signs of winter itch
Who gets winter itch?
Winter itch can affect the healthy population of all ages, but has a higher prevalence in older people with dry skin.
- It is uncommon in children and adolescents.
- It affects men and women equally.
- It is not influenced by socioeconomic status or personal hygiene.
What causes winter itch?
The exact cause of winter itch is unknown. Factors associated with winter itch include:
- Itching associated with cold weather, often coexisting with dry skin
- Itch presenting in autumn and winter, and clearing up during the summer months
- The aggravation of symptoms by the wearing of certain types of textures, such as flannel or woollen wear.
Similar symptoms have also been reported in patients exposed to refrigerated air conditioning during the summer months. Winter itch is not influenced by frequency of bathing or by the temperature of the bath water.
What are the clinical features of winter itch?
Winter itch does not cause a primary visible rash. The affected skin generally appears healthy, but usually slightly dry.
- The itch affects most or all parts of the body, but most commonly occurs on the legs.
- Typical sites are the inner surface of the thighs, above and behind the knees, on the calves, and around the ankles.
- It does not affect the hands, feet, face or scalp.
- The degree of irritation varies from mild to severe; when severe, it can result in great distress and discomfort, that may require medical attention.
- The itchiness is sudden in onset, and is generally most noticeable at night and when removing clothing.
Secondary lesions arise as a consequence of chronic scratching.
- The skin becomes erythematous with noticeable scratch marks.
- Scratched skin may be dry, rough and thickened (lichenified).
- Intense rubbing of the skin may cause desquamation.
- There may be a secondary folliculitis, with torn and broken hair shafts due to constant scratching.
How is winter itch diagnosed?
Winter itch can be associated and confused with other diseases that cause itchiness, particularly dermatitis (where there is a visible rash), and pruritus associated with systemic diseases (which tends to be generalised).
Detailed history taking and careful examination are important to rule out other potential causes of pruritus.
What is the treatment for winter itch?
Treatment is mainly to provide symptomatic relief and prevent scratching.
- Bathe in warm water prior to sleep. Some people report a benefit from the addition of sodium bicarbonate to the water (a quarter of a cup of baking soda swished around in a full bath).
- Emollients are the mainstay of treatment. Apply a moisturising cream after bathing and whenever the skin feels itchy or dry.
- Wear lightweight clothing such as silk, linen, and muslin.
- Avoid irritating fabrics, such as woollen clothing.
- Use topical corticosteroids to treat secondary dermatitis and lichen simplex.
- Capsaicin cream can be useful for localised areas of persistent itch.
Systemic agents are not indicated for winter itch, but oral antihistamines and systemic corticosteroids are sometimes prescribed as a clinical trial.
What is the outcome for winter itch?
Winter itch normally resolves after the winter months.
- The duration of itching varies among individuals. It may last for a few days or weeks, and occasionally throughout the winter.
- Winter itch may recur throughout a person’s lifetime or disappear permanently at the end of the first attack.