**Question:** An elderly female presents with the features of fever, headache, diplopia. Biopsy of the artery revealed panarteritis. What is the most probable diagnosis -

A. Polyarteritis Nodosa
B. Giant Cell Arteritis
C. Takayasu's Arteritis
D. Kawasaki Disease

**Core Concept:** Panarteritis refers to inflammation affecting multiple arterial layers, leading to symptoms like fever, headache, and diplopia. This can be due to various conditions affecting the arterial walls, including vasculitis.

**Why the Correct Answer is Right:** Among the given options, Polyarteritis Nodosa (PAN) is the most probable diagnosis for an elderly female presenting with panarteritis. PAN is a systemic vasculitis affecting medium-sized arteries and arterioles, resulting in inflammation and damage to the arterial walls. This leads to the clinical manifestations mentioned, including fever, headache, and diplopia.

**Why Each Wrong Option is Incorrect:**

A. Giant Cell Arteritis (GCA) is a different type of vasculitis affecting large and medium-sized arteries, particularly the temporal artery. GCA presents differently, with more common symptoms like jaw claudication, scalp tenderness, and a pulsatile temporal artery enlargement.

B. Kawasaki Disease (KD) is a childhood vasculitis affecting small and medium-sized arteries. It is unlikely in an elderly female and presents with different symptoms like mucocutaneous changes, conjunctivitis, and cervical lymphadenopathy.

C. Takayasu's Arteritis (TAK) is a rare vasculitis involving the aorta and its main branches, affecting predominantly young females. It presents with symptoms like hypertension, claudication, and aortic regurgitation.

**Clinical Pearl:** Vasculitis diagnoses require a comprehensive clinical evaluation, including a thorough history, physical examination, and appropriate investigations. These conditions can present with overlapping symptoms, making diagnosis challenging. Therefore, a clinical suspicion and appropriate investigations are essential in establishing an accurate diagnosis.