A crusty burn is a third-degree burn from thermal burns, by the highest degree of burn injury. The injury affects the whole layer of skin, and can even reach deep into the subcutaneous, muscle and bone. Skin necrosis and dehydration can form a scab, which is like leather when touched and has even charred. Skin necrosis and dehydration can form a scab, so it is also called a scab burn. There is no sensation in the wound; the skin temperature is low. Natural healing is very slow, must hold the scab off, granulation tissue growth and then form a scar, only the edge of the epithelium, not only the loss of skin function and often cause deformity some trauma and even difficult to self-heal. The burn injury can affect the whole skin layer, and can even reach deep into the subcutaneous, muscle, bone, etc. Skin necrosis and dehydration can form a crust, so also known as crust burns. The trauma surface is blister-free, waxy white or scorched yellow, or dendritic embolic vessels are visible; it is like leather to the touch; it is even charred. Sensation is absent; skin temperature is low. Natural healing is very slow, and the scab must be held to fall off, and granulation tissue grows and then forms a scar, with only epithelium on the edge, which not only loses skin function but often causes deformity. What tests should be done in the early stages of crusted burns? Laboratory and other ancillary tests. In the early stage of severe burns, when body fluids are lost and blood is concentrated, the red blood cell count, hemoglobin amount and red blood cell pressure are significantly increased in routine blood tests, and the specific gravity of urine is increased; in metabolic acidosis, the carbon dioxide binding capacity is reduced and non-protein nitrogen is increased, and blood gas analysis and the determination of serum Na↑+, K↑+ and CI↑- can be checked when available to determine whether there is acidosis; in sepsis In sepsis, the total white blood cell count is often between 10×10↑9/L and 25×10↑9/L, and the neutrophils reach 85% or more, and the left shift of the neutral nucleus and toxic granules can be seen; positive blood culture can help to diagnose; pus bacterial culture and drug sensitivity test can help to determine the type of pathogenic bacteria, and antibiotics can be selected in a targeted manner.