Second-degree burns are more serious than first-degree burns and usually have a blister. A second-degree burn occurs when the epidermis and dermis layer of skin are burned.
It is recommended that if the second-degree burn is over more than ten percent of your body, you should seek medical treatment immediately.
Second-degree burns generally heal in two or three weeks. Sometimes the burn will take more than three weeks to heal because of the size of the burn. Also, as the burn heals it will itch. DO NOT itch or scratch the burn. Itching and scratching could cause an infection. For a year, the burned area may be uber-sensitive to light. Apply sunscreen to the burn area after the burn heals.
According to various medical sources, symptoms of second-degree burns include:
• Blisters -- they sometimes break open and the area looks wet with a bright pink to cherry red color
https://www.empowher.com/burns/content/do-s-and-don-ts-treating-second-degree-burns