## **Core Concept**
The triple response of Lewis, also known as the triple response of skin, is a physiological response to mild damage of the skin, typically assessed through stroking or applying pressure. It involves three main reactions: **red line**, **flare**, and **wheal**. The flare response is a key component of this reaction.

## **Why the Correct Answer is Right**
The flare response in the triple response occurs due to **histamine-induced vasodilation** and **axon reflex**. When the skin is stroked or mildly damaged, it leads to the release of histamine from damaged skin cells and mast cells. Histamine then acts on nearby blood vessels, causing vasodilation. Additionally, histamine stimulates nerve endings, which through an axon reflex, release **substance P** and **calcitonin gene-related peptide (CGRP)**, leading to further vasodilation and the characteristic flare.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not accurately describe the mechanism behind the flare response.
- **Option B:** This option might relate to aspects of the immune response or inflammation but does not specifically explain the flare response in the context of the triple response.
- **Option D:** This option does not accurately describe the mechanism of the flare response.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that the **flare response is an axon-mediated reflex**. This is clinically significant because it highlights the neurogenic component of inflammation and can be diminished or absent in conditions with neuropathy or certain autonomic nervous system disorders.

## **Correct Answer:** .