Burn Degrees: First, Second and Third Explained

A first degree burn reddens only the outer layer of skin and usually heals within days without a scar. A second degree burn reaches deeper and blisters; a shallow one closes in one to two weeks, a deep one takes longer. A third degree burn destroys the full thickness of the skin, often looks white, leathery or charred rather than pink, and needs specialized care, usually at a burn center. The degree is decided by how deep the heat reached, not by how large the burn looks or how much it hurts.

What is a first degree burn?

A first degree burn, also called a superficial burn, damages only the epidermis, the thin outer layer of skin. The skin turns red, is painful to the touch, and may swell slightly, but it does not blister. A common sunburn is a textbook first degree burn, and so is a brief touch against a hot pan handle that leaves red skin without a blister.

These burns heal on their own within days as the damaged outer layer sheds and new skin forms underneath. Cool water, a moisturizing lotion once the skin is no longer hot, and over-the-counter pain relief are usually all that is needed. A first degree burn rarely leaves a scar, though the skin may be temporarily darker or lighter than the area around it.

What is a second degree burn?

A second degree burn, or partial thickness burn, reaches through the epidermis into the upper part of the dermis, the layer beneath it. The hallmark sign is blistering: fluid collects between the damaged layers and lifts the skin into a bubble. The skin underneath is red, wet looking and very painful, often more painful than a deeper burn because more nerve endings are intact and exposed.

A superficial partial thickness burn, closer to the surface, usually heals in one to two weeks with minimal scarring if it is kept clean and protected. A deep partial thickness burn, reaching further into the dermis, takes two weeks or more, often scars, and is frequently treated by a surgeon with removal of the dead tissue and a skin graft. The blister itself should generally be left intact; it is a natural, sterile covering over the healing tissue underneath, and an intact blister protects against infection better than an open wound does.

MedlinePlus advises calling 911 for a second degree burn more than 2 to 3 inches wide, or for a burn on the hands, feet, face, groin, buttocks or over a major joint, because of the risk to function and the risk of infection in those locations.

What is a third degree burn?

A third degree burn, or full thickness burn, destroys the entire epidermis and dermis and can reach into the fat, muscle or bone beneath. Because the nerve endings in the skin are destroyed along with the tissue, a third degree burn is sometimes less painful at the center than a shallower burn around its edges, which is a dangerous sign rather than a reassuring one: a burn that does not hurt may be the deepest one in the room.

The surface of a third degree burn looks different from the other two: white, grey, leathery, waxy or black and charred, dry rather than wet, and it does not blanch, meaning it does not turn pale when pressed. These burns heal only slowly from their edges; unless very small, they need surgery to remove the dead tissue and a skin graft, and they always warrant emergency care. A full thickness burn of any size is one of the American Burn Association criteria for consulting or transferring a patient to a burn center.

How can a caregiver tell the degrees apart at a glance?

Color and texture give the fastest read. A first degree burn is red and dry, with normal skin texture underneath the redness. A second degree burn is red or pink, wet looking, and blistered. A third degree burn is pale, white, leathery or charred, and dry despite the depth of the injury. Pain is a less reliable guide than it seems: a shallow burn often hurts the most because its nerves are intact and exposed, while a very deep burn can be the quietest one in the room because the nerves there have been destroyed.

When in doubt about depth, treat the burn as the more serious category rather than the less serious one. A burn that is hard to read, that covers a sensitive area, or that involves a child, an older adult, or someone with a chronic condition should be seen by a clinician even if it looks like it might be a second degree burn rather than a third.

Does the degree change the first aid?

The first move is the same for any burn: stop the source of heat, then cool the area with cool running water, not ice, for about twenty minutes, the duration the NHS recommends. What changes is everything that happens next. A first degree burn generally needs nothing more than that cooling, a moisturizer once it stops feeling hot, and time. A second degree burn needs a clean, loose dressing, attention to the blister, and a decision about whether its size or location means it needs a clinician. A third degree burn needs an emergency room or a burn center, full stop, regardless of how small the area looks, because the surface appearance of a full thickness burn does not predict what is happening in the tissue beneath it.

When does the degree decide a trip to the burn center?

The American Burn Association uses depth as one of several referral criteria alongside size, location and the patient's age and health. Any full thickness burn calls for burn center consultation or transfer. A partial thickness burn does so once it covers 10 percent or more of the body's surface, or when it sits on the face, hands, feet, genitals, perineum or over a joint. Children 14 and under may also benefit from referral for any burn. A first degree burn almost never requires a burn center on its own, though a very large one, covering a significant portion of the body, still deserves a call to a clinician.

Knowing the degree is one of the first useful facts about any burn, along with its size and location. A caregiver who can describe color, texture and whether the skin has blistered is giving the single most useful description available before a clinician ever sees the burn in person.