A second-degree burn damages both the outer layer of skin (epidermis) and part of the layer beneath it (dermis). This is why doctors also call it a “partial-thickness” burn. The hallmark sign is blistering, which typically forms within 24 hours as the two skin layers separate. These burns are notably painful because nerve endings in the dermis are exposed and irritated but not destroyed.
What It Looks and Feels Like
The burned area appears red, swollen, and blistered. The skin often looks wet and shiny where blisters have formed or broken open. In deeper burns, you may notice white or discolored patches in an irregular pattern across the wound. The entire area is typically tender to the touch, and even light air movement across the burn can cause significant pain.
This level of pain actually distinguishes second-degree burns from more severe third-degree burns. In a third-degree burn, nerve endings are completely destroyed, so the area may feel numb. A second-degree burn hurts more precisely because those nerves are damaged but still functioning.
Superficial vs. Deep Partial-Thickness
Not all second-degree burns are the same. They fall into two categories that heal very differently.
Superficial partial-thickness burns affect only the upper portion of the dermis. They’re red, painful, and form clear blisters. They blanch (turn white briefly) when you press on them, a sign that blood flow to the area is intact. These burns generally heal in 7 to 21 days. Scarring is unusual, though the skin color in the area may look lighter or darker for months afterward.
Deep partial-thickness burns extend further into the dermis. The skin may appear more mottled or waxy, and blisters can be larger or more irregular. These take significantly longer to heal, sometimes requiring skin grafting if the wound doesn’t close on its own. The risk of permanent scarring is much higher with deep partial-thickness injuries.
A burn that initially looks superficial can reveal itself as partial-thickness 12 to 24 hours later, so a wound that seems mild on day one may look worse by day two. This is normal progression, not necessarily a sign that something has gone wrong.
Immediate First Aid
The single most important thing to do is cool the burn by running cool (not cold) water over it for about 10 minutes. This removes heat from the tissue and limits how deep the injury spreads. After cooling, cover it loosely with a clean bandage to protect the area and reduce pain from air exposure. Avoid adhesive bandages, which can stick to damaged skin and cause further injury when removed.
Do not pop blisters. The fluid-filled blister is a natural barrier protecting the raw tissue underneath. Breaking it opens the door to infection.
What Not to Put on a Burn
Several popular home remedies actively make burns worse. Butter, mayonnaise, and petroleum jelly trap heat in the wound, slowing healing and creating a breeding ground for bacteria. Toothpaste can intensify pain and increase the risk of both infection and scarring. Mustard contains vinegar that can chemically irritate the already-damaged tissue. Even ice is harmful: it constricts blood flow to the area, can damage tissue further, and in some cases causes a mild cold injury on top of the burn.
The only thing you need in the first minutes is cool running water and a clean covering. Skip the medicine cabinet improvisation.
How Doctors Assess Burn Severity
Beyond depth, the other critical factor is how much skin is affected. Medical teams use a system called the Rule of Nines, which divides the adult body into sections that each represent roughly 9% of total body surface area. The head accounts for 9%, each arm 9%, and so on, with the perineum (groin area) estimated at 1%. This gives a quick, reproducible estimate that helps determine whether a burn needs specialized care.
Burns on certain locations also carry extra risk regardless of size. The face, hands, feet, groin, and any area over a joint all warrant professional evaluation because of the potential for functional impairment or complications during healing.
Signs of Infection
Burn wounds are vulnerable to infection because the skin’s protective barrier is broken. Watch for oozing from the wound (especially if the discharge is cloudy or discolored), red streaks spreading outward from the burn edges, increasing pain after the first couple of days, or fever. Any of these signals that bacteria have entered the wound and that professional treatment is needed.
Healing and Scarring
Superficial second-degree burns are the best healers. Most close within three weeks, and the new skin, while initially pink and sensitive, usually returns to a near-normal appearance over time. Pigment changes (areas that look slightly lighter or darker than surrounding skin) are the most common lasting effect and can persist for several months to a year.
Deep second-degree burns are less predictable. If they don’t heal within about three weeks, they may need surgical intervention such as skin grafting to prevent severe scarring. Even with treatment, deep partial-thickness burns are more likely to leave raised or textured scars. Keeping the healing skin moisturized and protected from sun exposure helps minimize long-term discoloration.
Burns that initially seem to straddle the line between superficial and deep can shift category during the first few days. The full extent of tissue damage sometimes takes 48 to 72 hours to declare itself, which is why follow-up evaluation matters for any burn you’re uncertain about.