Which of the following is an example of small vessels vasculitis?
**Core Concept**
Small vessel vasculitis involves inflammation of the small blood vessels, including capillaries, venules, arterioles, and sometimes small arteries. This condition can lead to various symptoms depending on the location and severity of the inflammation.
**Why the Correct Answer is Right**
Polyarteritis nodosa (PAN) is a classic example of small vessel vasculitis. It is characterized by necrotizing inflammation of the medium and small-sized arteries, which can lead to organ damage. The exact cause of PAN is unknown, but it is thought to be related to autoimmune mechanisms and immune complex deposition. The inflammation in PAN can lead to the formation of aneurysms, thrombosis, and organ dysfunction.
**Why Each Wrong Option is Incorrect**
**Option A:** Giant Cell Arteritis is a form of large vessel vasculitis, primarily affecting the aorta and its major branches. It is characterized by granulomatous inflammation and is often associated with polymyalgia rheumatica.
**Option B:** Wegener's Granulomatosis (Granulomatosis with Polyangiitis) is a form of medium and large vessel vasculitis that primarily affects the respiratory tract and kidneys. It is characterized by granulomatous inflammation and the presence of anti-neutrophil cytoplasmic antibodies (ANCA).
**Option C:** Henoch-Schönlein Purpura (HSP) is a form of small vessel vasculitis that primarily affects children and young adults. It is characterized by IgA deposits and inflammation of the small blood vessels, leading to symptoms such as purpura, arthritis, and abdominal pain.
**Clinical Pearl / High-Yield Fact**
Small vessel vasculitis can present with a wide range of symptoms, including skin rashes, joint pain, kidney disease, and gastrointestinal symptoms. It is essential to consider small vessel vasculitis in the differential diagnosis of patients presenting with these symptoms.
**Correct Answer:** C. Henoch-Schönlein Purpura