Which condition is characterized by less than 10% of body surface area affected?

The correct response relates to Steven Johnson Syndrome (SJS), a severe skin reaction that typically affects a smaller surface area of the body compared to its more severe counterpart, Toxic Epidermal Necrolysis (TEN). SJS is characterized by having less than 10% of the body surface area involved, while TEN usually involves over 30% of the body.

The condition is often triggered by medications, infections, or other factors and leads to symptoms such as painful red or purplish patches on the skin, blisters, and the shedding of the top layer of skin. Because the affected area is relatively small in comparison to other conditions, SJS is classified distinctly as having less than 10% involvement.

In contrast, hyperemesis gravidarum relates to severe nausea and vomiting during pregnancy, shock refers to a critical condition resulting from inadequate blood flow, and TEN is a more extensive skin reaction than SJS. Each of these other conditions does not directly correlate with a body surface area involvement criterion, making them unrelated to the question regarding skin involvement percentage.