A sun allergy is an immune system reaction to sunlight’s UV rays, causing skin issues like rashes, hives, and blisters. Unlike a sunburn, which is direct UV damage, a sun allergy involves the body mistakenly identifying sun-altered skin as a threat, triggering an immune response.
Recognizing Sun Allergy Reactions
Sun allergy symptoms can appear minutes, hours, or days after sun exposure. Common signs include itchiness, stinging, tiny bumps that may merge into raised patches, redness, blisters, or hives.
Polymorphous Light Eruption (PMLE) often presents as small red bumps, larger red patches, or blisters on sun-exposed areas like the chest, neck, arms, and legs. These rashes typically develop hours after sun exposure and feel itchy or burning. Solar Urticaria causes hives to form rapidly, often within minutes of sun exposure, with intense itching and burning. Solar urticaria symptoms subside within hours of leaving the sun, but can cause systemic symptoms like headache or nausea if large areas are exposed.
A sunburn results in uniform redness, warmth, and pain, sometimes with blistering, appearing a few hours after exposure. Sun allergy rashes present as bumps or hives and are more likely to be itchy, while sunburns are more painful. Sun allergy rashes typically occur only on sun-exposed skin, but photoallergic reactions can affect unexposed areas.
Treating Acute Sun Allergy Symptoms
When a sun allergy flare-up occurs, move out of direct sunlight to prevent further reaction. Continued sun exposure can worsen the rash.
Cooling the affected area with cool compresses or a cool bath provides relief. Apply soothing lotions like aloe vera or calamine to calm irritated skin and reduce itching. Moisturizers can also relieve irritation from dry, scaly skin.
Over-the-counter medications can manage symptoms. Oral antihistamines, like loratadine or cetirizine, reduce itching and hives. Mild corticosteroid creams decrease inflammation and soothe the skin. For severe reactions, a doctor might prescribe stronger oral corticosteroids.
Strategies for Preventing Sun Allergy
Preventing sun allergy reactions involves sun protection and lifestyle adjustments. Limit direct sun exposure, especially during peak UV radiation hours (10 a.m. to 4 p.m.). Seek shade whenever possible during these times.
Wear protective clothing as a barrier against UV rays, including long-sleeved shirts, long pants, and wide-brimmed hats. Tightly woven fabrics and darker colors provide better UV protection. Some clothing has a Sun Protection Factor (UPF) rating.
Apply broad-spectrum sunscreen with an SPF of at least 30 to exposed skin, even on cloudy days. Sunscreen should block both UVA and UVB rays. Mineral-based sunscreens containing titanium dioxide or zinc oxide are often recommended for sensitive skin, as they are less likely to cause irritation. Apply sunscreen generously 30 minutes before sun exposure and reapply every two hours, or more frequently after swimming or sweating. Gradually increasing sun exposure in spring and summer can help some individuals build tolerance.
When Professional Help is Needed
Consult a doctor or dermatologist if sun allergy symptoms are severe, widespread, or persist despite home treatments. Seek medical attention for signs of infection (increased pain, swelling, warmth, or pus) or if the allergy significantly impacts daily life. Unusual skin reactions after sun exposure also warrant evaluation.
A healthcare provider can diagnose the specific type of sun allergy, which is important because different types have varying triggers and management strategies. They may perform tests like phototesting, where skin is exposed to controlled UV light, or a skin biopsy to rule out other conditions. Depending on the diagnosis, a doctor might prescribe stronger medications, such as oral corticosteroids or immunosuppressants for chronic or severe cases. Specialized treatments like phototherapy may also be recommended, which involves controlled exposure to artificial UV light to help the skin build tolerance to sunlight.