**Temporal Arteritis**

**Core Concept**
Temporal arteritis, also known as giant cell arteritis, is a large vessel vasculitis that primarily affects the branches of the external carotid artery, particularly the temporal artery. It is a type of autoimmune disease characterized by inflammation of the blood vessels, leading to symptoms such as headache, jaw claudication, and visual disturbances.

**Why the Correct Answer is Right**
Temporal arteritis is a condition that predominantly affects individuals over the age of 50, with a peak incidence in the 7th and 8th decades of life. The exact cause is unknown, but it is thought to be related to an autoimmune response, with the presence of giant cells and granulomatous inflammation in the affected vessels. The condition is often associated with polymyalgia rheumatica, another inflammatory disorder.

**Why Each Wrong Option is Incorrect**
* **Option A:** Not a true statement about temporal arteritis. Temporal arteritis is indeed associated with polymyalgia rheumatica, a condition characterized by stiffness and pain in the muscles of the neck, shoulders, and hips.
* **Option B:** True statement about temporal arteritis. Temporal arteritis often presents with symptoms such as headache, scalp tenderness, and jaw claudication.
* **Option C:** Not a true statement about temporal arteritis. Temporal arteritis is a condition that primarily affects individuals over the age of 50, with a peak incidence in the 7th and 8th decades of life.
* **Option D:** Not a true statement about temporal arteritis. Temporal arteritis is characterized by inflammation of the blood vessels, leading to symptoms such as headache, jaw claudication, and visual disturbances.

**Clinical Pearl / High-Yield Fact**
A key clinical feature of temporal arteritis is the presence of a tender, swollen temporal artery, which may be associated with visual disturbances, including blindness. It is essential to diagnose and treat temporal arteritis promptly to prevent permanent visual loss.

**Correct Answer: C. Temporal arteritis is not primarily associated with individuals under the age of 50.**