Increased conduit vessel stiffness results in increased characteristic impedance of the aorta and decreased arterial compliance, which cause an increase in systolic blood pressure (SBP) and pulse pressure as well as a decrease in diastolic blood pressure (DBP).
Local trauma is the most common cause, followed by facial trauma, foreign bodies, nasal or sinus infections, and prolonged inhalation of dry air. Children usually present with epistaxis due to local irritation or recent upper respiratory infection (URI).
Anaphylaxis is an acute multiorgan system reaction. The most common organ systems involved include the cutaneous, respiratory, cardiovascular, and gastrointestinal (GI) systems. In most studies, the frequency of signs and symptoms of anaphylaxis is grouped by organ system. Anaphylactic reactions almost always involve the skin or mucous membranes. Greater than 90% of patients have some combination of urticaria, erythema, pruritus, or angioedema.