Histamine release during cryotherapy may cause which of the following?

• A. Increased blood pressure or syncope
• B. Decreased blood pressure
• C. Nausea
• D. Local warmth

Answer: (A)

Histamine release during cryotherapy is a mediator response from mast cells that causes vasodilation and increased vascular permeability in the treated area. That local reaction accounts for the warmth and redness you can see at the site. But histamine can also influence systemic autonomic responses when the reaction is enough or when paired with cold exposure. In some individuals, these systemic changes can manifest as fluctuations in blood pressure, and in certain cases may contribute to syncope if cerebral perfusion drops briefly. Because the question is about potential systemic effects, the scenario most consistent with that risk is an increase in blood pressure or a fainting episode. Local warmth is a common local sign, but it doesn’t capture the systemic hemodynamic risk described. Nausea can occur but is less directly tied to the primary histamine-mediated systemic effect in this context.