Second-degree burns are injuries to the skin caused by heat, radiation, electricity, chemicals, or friction. These burns are also called partial-thickness burns.

There are two types of second-degree burns, defined by their depth:

• Superficial partial-thickness burns injure the first and second layers of skin and are often caused by hot water or hot objects. The skin around the burn turns white (blanches) when pressed, then turns back to red. The burn is moist and painful with blistering and swelling that usually lasts for at least 48 hours.
• Deep partial-thickness burns injure deeper skin layers and are white with red areas. They are often caused by contact with hot oil, grease, soup, or microwaved liquids. This kind of burn is not painful, but it can cause a sensation of pressure. The skin looks spotted, remains white when pressed, may appear waxy in some areas, and is dry or slightly moist. Possible infection is an important concern with these burns.

It may take several days before symptoms develop and it becomes clear whether the burn is superficial or deep.

Treatment varies for a second-degree burn depending on its size, depth, and a person's age and overall health. With all burns, it is important to watch for and seek treatment for any signs of infection. Second-degree burns may leave scars after the burns heal.