A 30 years old male patient presents with complaints of weakness in right upper and both lower limbs of last 4 months. He developed digital infarcts involving 2nd and 3rd fingers on right side and 5th finger on left side. ern examination, P was 160/140 min Hg, all peripheral pulses were palpable and there was asymmetrical neuropathy. Investigations showed a Hb 12 gm, TLC – 12000 Cu mm, Platelets 4,30,000, ESR – 49 mm. Urine examination showed proteinuria and RBC -10 -15/ hpf with no casts. Which of the following is the most likely diagnosis ?

**Core Concept**
The patient's presentation of limb weakness, digital infarcts, hypertension, peripheral neuropathy, and renal abnormalities suggests a systemic vasculitic process affecting multiple organ systems.

**Why the Correct Answer is Right**
The patient's symptoms and laboratory findings are consistent with a diagnosis of **Polyarteritis Nodosa (PAN)**. PAN is a medium-vessel vasculitis characterized by the presence of necrotizing inflammation of blood vessels, leading to ischemia and infarction of affected organs. The patient's digital infarcts, neuropathy, and renal involvement are all classic features of PAN. The presence of hypertension and proteinuria also supports this diagnosis.

**Why Each Wrong Option is Incorrect**
**Option A:** **Wegener's Granulomatosis** is a form of granulomatosis with polyangiitis (GPA) that primarily affects the respiratory tract and kidneys. While GPA can cause renal involvement, the patient's presentation of digital infarcts and peripheral neuropathy is less typical for GPA.

**Option B:** **Rheumatoid Arthritis** is a systemic autoimmune disease that can cause vasculitis, but the patient's presentation of digital infarcts and hypertension is not typical for rheumatoid arthritis.

**Option C:** **Thromboangiitis Obliterans** (Buerger's disease) is a type of vasculitis that primarily affects the small and medium-sized vessels of the extremities. While this disease can cause ischemia and infarction of the affected limbs, the patient's renal involvement and hypertension are not typical for Buerger's disease.

**Option D:** **Henoch-Schönlein Purpura (HSP)** is a form of vasculitis that primarily affects the small vessels and is characterized by the deposition of IgA immune complexes. While HSP can cause renal involvement, the patient's presentation of digital infarcts and hypertension is not typical for HSP.

**Clinical Pearl / High-Yield Fact**
PAN is a medium-vessel vasculitis that can affect multiple organ systems, including the kidneys, nervous system, and gastrointestinal tract. The presence of digital infarcts and hypertension should raise suspicion for PAN, particularly in patients with a history of smoking or exposure to toxic substances.

**Correct Answer:** C. Polyarteritis Nodosa.

✓ Correct Answer: A. Polyarteritis nodosa