Total body surface area (TBSA) is an assessment of injury to or disease of the
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different ...
, such as
burn
A burn is an injury to skin, or other tissues, caused by heat, cold, electricity, chemicals, friction, or ultraviolet radiation (like sunburn). Most burns are due to heat from hot liquids (called scalding), solids, or fire. Burns occur ma ...
s or
psoriasis
Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to comple ...
.
In adults, the
Wallace rule of nines can be used to determine the total percentage of area burned for each major section of the body.
In burn cases that involve partial body areas, or when dermatologists are evaluating the
Psoriasis Area and Severity Index (PASI) score, the patient's palm can serve a reference point roughly equivalent to 1% of the body surface area.
For children and infants, the
Lund and Browder chart is used to assess the burned body surface area. Different percentages are used because the
ratio
In mathematics, a ratio shows how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8:6, which is equivalent to the ...
of the combined surface area of the head and neck to the surface area of the limbs is typically larger in children than that of an adult.
Types of Burns
Typical values for common groups of humans follow.[O'Sullivan, Susan B., Schmitz, Thomas J. Physical Rehabilitation. 5th ed. F.A. Davis Company, Philadelphia, 2007. p. 1098, Fig 27.9.] (Due to rounding, values may not add to 100%.)
References
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Skin anatomy