nonblanching

Nonblanching refers to skin or mucosal lesions that do not turn pale when pressure is applied. The blanch test distinguishes normal capillary perfusion from hemorrhagic lesions, which persist because blood has leaked into the skin or mucosa.

The sizes of nonblanching lesions range from petechiae, tiny red spots, to larger purpura and ecchymoses.

Causes include platelet disorders such as thrombocytopenia or platelet dysfunction, coagulation abnormalities, vasculitis, trauma, infections, and drug reactions. Some cases are benign, such as senile purpura in older adults; others may reflect serious conditions like meningococcemia.

Evaluation combines history, physical examination, and laboratory testing. Rapidly spreading nonblanching rash with fever or systemic symptoms warrants urgent assessment. Routine workup typically includes CBC with platelets, coagulation studies (PT, aPTT), inflammatory markers, and, if febrile, blood cultures.

Management targets the underlying cause; benign lesions may resolve without specific therapy, while life-threatening etiologies require prompt medical care. Prognosis varies with the cause and the speed of diagnosis.