**Question:** Necrotizing arteritis with fibrinoid necrosis is -

A. Rheumatoid arthritis
B. Takayasu's arteritis
C. Giant cell arteritis
D. Kawasaki disease

**Core Concept:**
Necrotizing arteritis with fibrinoid necrosis refers to a specific type of vasculitis that affects the arterial walls, leading to inflammation, necrosis, and the accumulation of fibrinoid material. Vasculitis is a group of conditions characterized by inflammation of blood vessels, which may be due to various causes including autoimmune disorders, infections, or medication reactions.

**Why the Correct Answer is Right:**
Choice C, Giant Cell Arteritis (GCA), is the correct answer because it is a specific type of vasculitis that primarily affects the large and medium-sized arteries, particularly the temporal arteries. GCA is characterized by the presence of giant cells (large macrophages) within the arterial wall, leading to inflammation, necrosis, and fibrinoid necrosis.

**Why Each Wrong Option is Incorrect:**

A. Rheumatoid arthritis is an autoimmune disorder primarily affecting the small joints and synovial membranes, not large and medium-sized arteries. It is marked by synovial inflammation and cartilage and bone destruction, not necrotizing arteritis with fibrinoid necrosis.

B. Takayasu's arteritis is a form of vasculitis affecting the aorta and its major branches, particularly in young females. Unlike necrotizing arteritis with fibrinoid necrosis, Takayasu's arteritis is characterized by a decrease in vessel caliber and lumen, resulting in hypertension and collateral vessel formation.

D. Kawasaki disease is a childhood vasculitis that primarily affects the coronary arteries, leading to dilatation and ectasia. It is typically seen in young children and is not characterized by necrotizing arteritis with fibrinoid necrosis.

**Clinical Pearls:**

Giant cell arteritis, also known as temporal arteritis, is a type of vasculitis that predominantly affects the elderly population, particularly those over 50 years old. It presents with nonspecific symptoms such as headaches, jaw claudication, and temporal artery tenderness. Early diagnosis and treatment are essential to prevent vision loss and other serious complications.

In conclusion, necrotizing arteritis with fibrinoid necrosis is a feature of Giant Cell Arteritis (GCA), while the other options represent distinct clinical entities with different presentations, characteristics, and affected vessels.