What is the term for the nonblanching rash seen on flexor surfaces in cases of scarlet fever?

The term for the nonblanching rash seen on flexor surfaces in cases of scarlet fever is known as Pastia Lines. This phenomenon specifically refers to the linear petechiae or erythrodermic rash that becomes more pronounced in areas where the skin is flexed, such as the antecubital and popliteal fossa. Pastia Lines are a characteristic finding in scarlet fever, which is caused by group A Streptococcus.

In scarlet fever, the rash appears after the initial symptoms of fever and sore throat, often showing a distinct texture and color, aligned with the bacterial toxin's effects on the skin. The identification of Pastia Lines helps differentiate scarlet fever from other conditions that may produce similar skin manifestations. Understanding this specific manifestation contributes to the overall diagnosis and management of scarlet fever, allowing for appropriate treatment of the underlying infection.