A Patient's Guide to Eczema
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Sunscreen Allergies

Allergies to sunscreens are not uncommon. Such reactions can be described as irritant, allergic, or photo-allergic. Sensitivities to sunscreens can appear anywhere on the body where the product is applied, but it tends to be more prevalent on areas receiving the greatest sun exposure, such as the face, backs of the hands and forearms, upper chest and lower neck (referred to as photo-contact dermatitis).

Contact eczema caused by sunscreens can result from an allergic action to active ingredients or to fragrances or preservatives that are contained in the product. Because there are multiple active agents that are formulated in each sunscreen product, it may be difficult to pinpoint the exact ingredient that is causing the contact dermatitis, but patch testing may be helpful.

The active sunscreen chemicals that have been found to cause the majority of allergic reactions include PABA (para-aminobenzoic acid), benzophenones, cinnamates, dibenzoylmethanes, octocrylene, and salicylates.

Limited, controlled amounts of sun exposure can have some beneficial effects on atopic dermatitis, but prolonged or excessive exposure can cause potentially serious skin damage and increase the risk for skin cancer.

For individuals with eczema, finding a suitable sunscreen can be a challenge. If regular formulations are unsuitable, try sensitive skin formulations or physical sunblocks, or even consider milder preparations that are specifically made for children.

Chemical Sunscreens and Physical Sunblocks

Sunscreens are broadly divided into two groups: chemical and physical. Chemical sunscreens are made from synthetic substances that effectively absorb UV radiation. Chemical sunscreens produce a chemical reaction when exposed to UV rays, which generates heat. Physical sunscreens (also known as sunblocks), such as titanium dioxide or zinc oxide, are made from mineral particles that reflect or block UV rays, similar to a mirror, and they tend to cause less skin irritation.

Physical sunblocks, unlike chemical sunscreens, do not produce heat when exposed to UV light. The only disadvantage is that physical sunscreens can leave a whitish or fluorescent appearance due to the fine particles in the preparation. However, newer advanced formulations are virtually transparent.

Tips and Information about Sunscreen Use

  • A comprehensive sun smart approach includes using a suitable sunscreen, wearing protective clothing and a hat, and avoiding the times of peak UV intensity (between 10 a.m. to 4 p.m.).
  • Always check the ingredient list to ensure that the product does not contain ingredients for which you have known sensitivities to.
  • The product must provide a minimum sun protection factor (SPF) of 15 for routine daily exposure; a higher SPF (preferably 30) is recommended for more intensive sun exposure. An SPF of 15 indicates that the product blocks about 93%of the UVB rays, SPF30 offers 97% protection and SPF50, 98%.
  • Make certain broad spectrum coverage is provided, meaning it protects against both UVA and UVB rays (UVB causes sunburns, whereas UVA penetrates deeper into the skin and causes premature aging and skin damage)
  • Sunscreens should be reapplied after water exposure or every 2 hours while engaging in outdoor activities, particularly if heavy perspiration occurs.
  • The effectiveness of sunscreens depends on if an adequate amount of the product is used, time of day and year, and the amount of sweating that occurs.
  • Recommended guidelines for adequate sunscreen application:
    • Use more than half a teaspoon each for the head and neck area, right arm and left arm.
    • Use more than a teaspoon each for the posterior torso, anterior torso, right leg, and left leg.
  • After sun exposure, wash residual sunscreen off with a mild cleanser and apply moisturizer to protect and restore hydration to the skin.