Eczema is a common skin condition characterized by inflammation, intense itching, and a compromised skin barrier function. This weakened barrier makes the skin highly susceptible to environmental irritants and moisture loss, which can lead to painful flare-ups. Sun exposure presents a dual challenge for those with eczema, as ultraviolet (UV) radiation must be blocked to prevent further skin damage, yet many traditional sunscreens contain ingredients that can trigger irritation and allergic reactions. Finding specialized sun protection is therefore a necessary step to safeguard sensitive, eczema-prone skin.
Physical Versus Chemical Sunscreen Filters
Sunscreens are categorized by their active UV-filtering ingredients, which function through two distinct mechanisms: physical and chemical. Chemical sunscreens contain organic compounds like avobenzone, oxybenzone, or octinoxate, which are absorbed into the upper layers of the skin. These filters work by absorbing UV radiation and converting it into a small amount of heat, which is then released from the skin. This process of absorption and conversion can sometimes lead to irritation or allergic contact dermatitis in sensitive individuals.
Physical sunscreens, also known as mineral sunscreens, use inorganic compounds, primarily zinc oxide and titanium dioxide, as their active ingredients. These minerals sit on the surface of the skin, forming a physical barrier that reflects and scatters UV radiation away from the skin cells. Because the mineral particles are not absorbed and are largely chemically inert, they are less likely to cause stinging, burning, or allergic reactions than their chemical counterparts. Mineral sunscreens are the preferred starting point for individuals managing eczema.
Zinc oxide and titanium dioxide offer broad-spectrum protection. While older mineral formulations were known for leaving a noticeable white cast on the skin, modern products often use micronized or tinted versions of these minerals to improve cosmetic elegance. For highly sensitive or broken skin, mineral formulas are better tolerated and should be prioritized, particularly on the face and areas of active eczema.
Irritating Ingredients to Avoid
Certain chemical UV filters, such as oxybenzone (benzophenone-3), avobenzone, and octocrylene, are known to cause allergic reactions or photoallergic contact dermatitis in some people. In photoallergic reactions, the UV rays interact with the chemical filter on the skin, creating a new substance that triggers an immune response and a subsequent rash. These ingredients should be avoided by those with eczema-prone skin.
Fragrances are one of the most common culprits for contact dermatitis, often listed as “parfum,” “perfume,” or “fragrance.” Alcohols, such as ethanol or denatured alcohol, are often added to sunscreens for a lighter, quicker-drying feel, but they can strip the skin of its natural moisture. This drying effect can compromise the already fragile skin barrier of an eczema sufferer, leading to stinging, burning, and increased dryness.
Other preservatives like parabens (e.g., methylparaben, propylparaben) and isothiazolinones (methylchloroisothiazolinone/methylisothiazolinone) are known to trigger eczema flare-ups. Dyes and synthetic colors should also be avoided, as these colorants can irritate sensitive skin.
Application Techniques and Product Selection
A preliminary patch test is a necessary step before fully committing to a new product, especially for sensitive skin. This involves applying a small amount of sunscreen to a discreet area, such as the inner forearm, and observing the spot for 24 to 48 hours for any signs of itching, redness, or flaking.
When choosing a product, formulations should be creamy lotions or balms, which are less likely to contain high concentrations of drying alcohol compared to sprays or gels. Sprays should be avoided because they can be difficult to apply evenly and risk inhalation, though stick formulas can be useful for targeted application around the eyes where liquid sunscreens might migrate and cause stinging. The product should offer broad-spectrum protection with a Sun Protection Factor (SPF) between 30 and 50, which blocks between 96.7% and 98% of UVB rays.
For application, sunscreen should be applied generously—about one ounce for the entire body and a teaspoon for the face—at least 15 to 20 minutes before sun exposure. Instead of rubbing vigorously, which can trigger itchiness, the sunscreen should be smoothed onto the skin in gentle, downward strokes, similar to applying an emollient. If an emollient is part of the daily routine, it should be applied first and allowed to absorb for about 30 minutes before the sunscreen is applied.
Reapplication every two hours, or immediately after swimming or heavy sweating, is required. At the end of the day, gentle removal is important to avoid mechanical irritation. The sunscreen should be washed off with a mild, fragrance-free, soap-free cleanser, rather than scrubbing the skin, to preserve the integrity of the skin barrier.