Sunburn is a form of skin injury caused by excessive exposure to ultraviolet (UV) radiation from the sun. This damage triggers an acute inflammatory response in the skin, manifesting as redness, warmth, and pain. Many people who experience a sunburn also notice intense itchiness. Understanding the biological reason for this common sensation can guide effective relief strategies.
The Mechanism of Sunburn Itching
The sensation of itch, known scientifically as pruritus, results from the body’s inflammatory reaction to damaged skin cells. UV radiation damages the DNA within skin cells, causing them to undergo programmed cell death. This cellular damage signals the immune system to begin the cleanup and repair process.
Specialized immune cells, like mast cells, flood the injured area and release chemical mediators, including histamine. Histamine stimulates specific nerve endings in the skin that transmit the itch signal to the brain. This irritation creates the mild to moderate itching sensation considered a normal part of the healing phase as the skin recovers.
Recognizing Severe Sunburn Itch
While mild itching is common, a small percentage of people experience an overwhelmingly intense, deep, and often painful form of pruritus, sometimes called “Hell’s Itch.” This severe reaction is distinct from the general healing itch. It is characterized by a sensation of deep throbbing, stinging, or feeling as if fire ants are biting beneath the skin.
This intense form typically begins 24 to 72 hours after the initial sun exposure, often on the back or shoulders. The exact cause is not fully understood, but it may involve damage to underlying nerve endings, triggering an overreaction in the nervous system. This intense pruritus can be debilitating, lasting for a few hours to a couple of days, and is often resistant to standard topical treatments.
When to Seek Medical Attention
Medical attention should be sought if the sunburn covers a large percentage of the body, if severe blistering occurs, or if systemic symptoms like fever, chills, dizziness, or confusion accompany the itch. These signs may indicate a second-degree burn or significant dehydration requiring professional care.
At-Home Relief Methods
Immediate application of cool compresses or taking a cool, brief shower can help reduce the skin’s temperature and soothe the nerve endings. Avoid using ice directly on the burn, as extreme cold can further damage the compromised skin. After cooling, gentle moisturizing is recommended, ideally with a light, oil-free product containing aloe vera or soy, which aids in hydration without trapping heat.
Over-the-counter 1% hydrocortisone cream can be applied to the affected areas for a few days to help calm the inflammation and reduce the itch. For internal relief, non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, can address both the pain and the underlying inflammation. Oral antihistamines may also provide benefit by blocking the histamine released during the initial inflammatory phase, potentially easing the urge to scratch.
It is crucial to avoid applying heavy, greasy ointments like petroleum jelly, as these can seal in heat and worsen the inflammatory process. Resist the urge to scratch the itchy area, as this can break the skin barrier and increase the risk of infection. Staying well-hydrated by drinking plenty of water is also necessary, as sunburn draws fluid to the skin’s surface, increasing the risk of dehydration.
Preventing Future Sunburns and Itching
The most reliable way to prevent the uncomfortable itching sensation is to prevent the sunburn itself. This requires a multi-faceted approach to sun protection whenever spending time outdoors.
Seeking shade, particularly during the peak sun hours between 10 a.m. and 4 p.m., significantly limits UV exposure. Protective clothing, including wide-brimmed hats and tightly woven fabrics, provides a physical barrier against the sun’s rays.
For exposed skin, apply a broad-spectrum sunscreen with a Sun Protection Factor (SPF) of 30 or higher at least 15 minutes before going outside. Sunscreen must be reapplied every two hours, or immediately after swimming or excessive sweating, to maintain adequate protection.