Sunshine, hives and atopic eczema

Solar Urticaria

• Urticaria is the medical term for what is also called hives, or nettle rash.

• It is a type of skin reaction that has many causes.

• Solar urticaria is a relatively rare type of urticaria. It is found world wide.

• It can start at any age, but those aged between 20 and 40 are most affected.

• Itchy wheals appear within minutes on sun-exposed areas, or where clothing is thin.

• The sun rays responsible include both ultraviolet A and ultraviolet B, but also visible light.

• Although the reaction is often relatively brief (less than 2 hours), the sensitivity to sunshine tends to be persistent. Only in some cases it resolves spontaneously.

• The reaction is often confused with the more common polymorphic light eruption. Here the reaction to sunlight lasts much longer (more than 48 hours).

Prevention

• Avoiding direct sunlight

• Use of a reflectant sunscreen: conventional screens are usually not effective

• Photoprotective window films  can be used on both the windows of a car, and windows of the home

• NB: If these measures are required long term, there is a risk of developing Vitamin D deficiency

Treatment

• Antihistamine medication: needs to be taken regularly, sometimes more than one type at the same time, and at higher doses than normal.

• Steroid medication by mouth is occasionally required.

• Phototherapy is sometimes used.
  

Atopy, urticaria and sunshine

• Atopy refers to the link that exists between three illnesses: atopic eczema, asthma and hay fever, the so-called atopic triad. Atopy is associated with some types of urticaria, especially those provoked by heat, physical exercise, stress and eating spicy food - cholinergic urticaria.
  

• However, the good news is that solar urticaria is not reported as especially associated with being atopic.

• Sunshine generally helps improve atopic eczema, but sun aggravated atopic eczema also occurs.

See:

• Are all-day suncreams a good idea?
• Holidays and eczema: better or worse?
• Phototherapy and atopic eczema
• Sunshine, vitamin D and eczema
• Sunblocks, sun-skin reactions and atopic eczema