Buzz
Solar urticaria is an uncommon skin disorder triggered by an allergic response to sunlight. Explore additional images of skin-related issues.
©iStockphoto.com/Ziga LisjakPack your sunglasses, swimsuit, and sunscreen. A sunny day is perfect for outdoor fun and relaxation. However, for some individuals, sunlight exposure leads to urticaria (pronounced ur-tuh-KAR-ee-uh), which is another term for hives.
Hives, a frequent allergic reaction, results in itchy, red welts on the skin. Approximately 20% of people will experience urticaria at least once in their lives [source: Asthma and Allergy Foundation of America]. Common triggers include allergic reactions to medications, foods (such as shellfish and nuts), pet dander, pollen, and stress. Solar urticaria is a rare type of hives caused by an allergy to sunlight.
If you develop an itchy rash after sun exposure, it’s likely not solar urticaria. This rare form of hives impacts only about three in every 100,000 people globally [source: Clinuvel Pharmaceuticals Ltd.]. While anyone can develop solar urticaria, it is most common among women and individuals under 40 [source: Salford Royal].
Solar urticaria is a genuine allergic reaction to sunlight. It occurs when the skin is exposed to ultraviolet (UV) radiation, even briefly. UV rays, which are invisible and harmful to the eyes and skin, are emitted by sunlight, tanning beds, and lamps. In individuals with solar urticaria, UV exposure triggers a severe red rash, often appearing in spring or summer on areas like the arms, chest, and legs that were covered during winter.
The exact cause of solar urticaria remains unclear, but some researchers suggest it may involve an immune system response [source: Baron, Asthma and Allergy Foundation of America].
Understanding this adverse reaction to sunlight can help you better prepare for outdoor activities with loved ones. But how can you determine if you have solar urticaria? Discover the symptoms on the following page.
Solar Urticaria Symptoms
A rash appearing after sunlight exposure could indicate solar urticaria. The nature of the rash differs among individuals and may involve
- Small, elevated bumps
- Red patches
- Itching or a burning feeling
- Swelling or blisters on sun-exposed areas
These symptoms frequently appear on skin recently exposed to sunlight. Areas like the face and hands, which are often exposed, may not react. Additionally, even skin covered by clothing can sometimes exhibit these symptoms [New Zealand Dermatological Society].
Solar urticaria typically develops within 30 minutes of sun exposure and usually fades quickly. If the skin is shielded from sunlight, the rash typically vanishes within hours and almost always within a day [source: Baron]. However, further sun exposure can worsen the condition [source: Salford Royal]. For some, solar urticaria becomes a recurring, chronic issue [source: Asthma and Allergy Foundation of America].
Individuals with solar urticaria may also experience general malaise. Additional symptoms can include headaches, nausea, or fainting [source: Baron]. If the rash persists, spreads, or covers a large area of clothed skin, consult a doctor. Seek immediate medical attention if the rash is accompanied by lip or eye swelling, difficulty breathing or swallowing, or fainting, as these could signal a severe allergic reaction unrelated to solar urticaria [source: Harvard Medical School].
Now that you’re familiar with the symptoms, continue reading to discover effective treatment methods.
When your body has an allergic reaction, such as to sunlight, it releases histamine. This chemical causes small blood vessels in the skin to expand, allowing fluid to escape. This process results in the raised patches and bumps known as hives.
Solar Urticaria Treatments
While solar urticaria can be distressing, several home remedies can alleviate redness and itching. Cool water can calm irritated skin, and cold compresses or a cool bath can reduce the rash’s heat. Over-the-counter antihistamines offer additional relief, while ibuprofen can ease soreness. Anti-itch or hydrocortisone creams can also minimize itching. Always consult your doctor or pharmacist before using over-the-counter medications to avoid interactions with prescriptions. The most effective treatment is avoiding sun exposure altogether.
Severe cases of solar urticaria require medical intervention. If home remedies and over-the-counter treatments fail, a doctor may prescribe stronger antihistamines or steroid creams [source: Harvard Medical School]. In extreme situations, further tests may be necessary, leading to tailored treatments like phototherapy. This involves controlled sunlight exposure to reduce your body’s allergic response [source: Salford Royal].
Solar urticaria is an uncommon allergic reaction to sunlight. Most sun-induced hives are not true solar urticaria but rather caused by a chemical reaction from substances like perfume or lotion on the skin. Certain medications can also heighten sun sensitivity, leading to hives.
Preventing solar urticaria involves adhering to a few straightforward guidelines. Avoid direct sunlight during peak hours, typically from mid-morning to mid-afternoon, by staying indoors or in shaded areas. Wear protective clothing, such as wide-brimmed hats, long-sleeved shirts, and long pants, to shield your skin. Additionally, apply a broad-spectrum sunscreen with an SPF of at least 15, as recommended by the American Academy of Dermatology, to block both UVA and UVB rays. Reapply sunscreen every two hours, even on overcast days, for optimal protection.
