Sunburn blisters are a clear sign that your skin has suffered a significant injury from ultraviolet (UV) radiation exposure. These fluid-filled pockets indicate a burn severity that requires careful attention. Understanding the biological process behind their formation is the first step toward managing them safely and promoting proper healing, and helps identify when professional medical intervention is required.
The Mechanism of Blister Formation
Blistering signifies that sun exposure has caused a second-degree burn, a deeper injury than a superficial sunburn. Intense UV radiation, primarily ultraviolet B (UVB) rays, penetrates the skin and directly damages the DNA within skin cells. This widespread cellular damage triggers a severe inflammatory response.
The body attempts to protect the underlying, healthy tissue from further damage and infection. Damaged blood vessels in the dermis, the layer beneath the epidermis, become highly permeable. This increased permeability allows clear fluid, consisting of plasma and lymphatic fluid, to leak into the tissue layers.
This fluid accumulation separates the epidermis from the underlying dermis. The resulting pocket of fluid creates the visible, raised blister, which functions as a natural, sterile biological dressing over the injury. Blisters typically form six to 24 hours after sun exposure, depending on the burn’s severity. The presence of blisters means the burn has extended beyond the epidermis and is now affecting the upper layer of the dermis.
Immediate At-Home Care for Sunburn Blisters
The primary rule in managing sunburn blisters is to keep them intact, as the skin provides the best protection against infection. Do not attempt to pop, drain, or peel the blisters, as this exposes the vulnerable underlying skin to bacteria and slows healing. If a blister breaks on its own, gently clean the area with mild soap and water. Then, apply an over-the-counter antibiotic ointment and cover it with a non-stick sterile gauze bandage.
To manage pain and reduce the inflammatory response, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen can be taken according to package directions. Cooling the burn area helps relieve discomfort and draw heat away from the skin. This can be achieved by applying cool, damp compresses or taking a cool bath or shower.
Once the initial heat has subsided, apply a gentle moisturizer or a product containing aloe vera to the unblistered, burned areas. Avoid using petroleum jelly on the overall burn, as it traps heat. However, it can be used sparingly as a protective barrier on a blister that has already popped. Increase fluid intake by drinking plenty of water to counteract the fluid loss and dehydration that accompanies a severe burn.
When to Consult a Medical Professional
A blistering sunburn can lead to serious complications requiring immediate medical attention. Seek professional care if blisters cover a large percentage of the body, such as an entire limb, or if they appear on sensitive areas like the face, hands, feet, or genitals. Blistering over more than 20% of the body surface area is considered a major injury.
Systemic symptoms, which indicate the burn is affecting the entire body, are a serious warning sign. These include a fever of 102 degrees Fahrenheit or higher, chills, severe nausea, or persistent vomiting. These symptoms may be a sign of severe dehydration or heat exhaustion, which can be life-threatening if not treated promptly.
Signs of infection within the blistered area also necessitate a medical visit. Look for increasing pain, worsening swelling, the presence of yellow or green pus draining from the blister, or red streaks extending away from the injury site. Any signs of confusion, dizziness, or faintness should also prompt an immediate call to a healthcare provider.