Cutaneous burn classification

Epidermal (superficial; was first degree) burns involve only the epidermal layer of skin. Partial-thickness burns (was second degree) involve the epidermis and portions of the dermis. They are characterized as either superficial or deep. Full-thickness burns (was third degree) extend through and destroy all layers of the dermis and often injure the underlying subcutaneous tissue. Deep burn injury (was fourth degree) extends into underlying soft tissue and can involve muscle and/or bone.