A 65-year-old woman with a 12-year history of symmetrical polyarthritis presents with splenomegaly, ulcerations over the lateral malleoli, and synovitis of the wrists, shoulders, and knees. Laboratory values show a white blood cell count of 2500/uL and a rheumatoid factor titer of 1:4096. What is the likely finding on this patient's white blood cell differential count?
Q542Easy
What crystalline material is characteristic of pseudogout?
Q543Medium
A patient presents with gritty pain in the eye and joint pain after a leisure trip. What is the most probable diagnosis?
Q544Easy
Which of the following organs is typically NOT affected by granulomatosis with polyangiitis (Wegener's granulomatosis)?
Q545Medium
Which statement regarding the renal involvement associated with SLE is true?
Q546Medium
A 30-year-old male patient presents with complaints of weakness in the right upper and both lower limbs for the last 4 months. He developed digital infarcts involving the 2nd and 3rd fingers on the right side and the 5th finger on the left side. On examination, BP was 160/140 mm Hg. All peripheral pulses were palpable, and there was asymmetrical neuropathy. Investigations showed Hb 12 gm%, TLC 12,000 per cu. mm, Platelets 4,30,000, and ESR 49 mm. Urine examination showed proteinuria and RBC 10-15/hpf with no casts. What is the most likely diagnosis?
Q547Medium
A 58-year-old man has the sudden onset late one evening of severe pain in his left great toe. There is no history of trauma. On examination there is edema with erythema and pain on movement of the left 1st metatarsophalangeal joint, but there is no overlying skin ulceration. A joint aspirate is performed and on microscopic examination reveals numerous neutrophils. Over the next 3 weeks, he has two more similar episodes. On physical examination between these attacks, there is minimal loss of joint mobility. Which of the following laboratory test findings is most characteristic for his underlying disease process?
Q548Medium
A 40-year-old obese man presents with intense pain in his left first metatarsophalangeal (MTP) joint for the past few hours. He has no history of trauma, fever, chills, and no previous similar episode. He has no history of renal disease or diabetes, though he has been told he is "prediabetic." He does not recall any recent skin infections and no family members have had any reported staphylococcal infection. On examination, he has a swollen, red, warm, tender first MTP joint on the left. Uric acid level is 9 mg/dL; serum creatinine is normal. What is the best treatment approach for this patient?
Q549Medium
A 22-year-old female Asian immigrant presents with complaints of malaise, fever, arm pain, loss of appetite, and visual problems. Her mother states that she fainted one week ago. The physician cannot palpate the patient's lower extremity pulses and notes that the radial pulses are weak. The erythrocyte sedimentation rate (ESR) is elevated. Which of the following is the most likely diagnosis?
Q550Medium
A 27-year-old man presents with a history of low back pain and stiffness. After several months of mild symptoms, he experiences more severe stiffness at night and hip pain. Physical examination reveals paravertebral muscle tenderness and limited lumbar spine flexion. X-ray of the lumbar spine shows sacroiliitis. In addition to recommending physiotherapy and exercise, what is the most appropriate next step in management?
Rheumatology and Immunology Indian Medical PG Practice Questions and MCQs
Question 541: A 65-year-old woman with a 12-year history of symmetrical polyarthritis presents with splenomegaly, ulcerations over the lateral malleoli, and synovitis of the wrists, shoulders, and knees. Laboratory values show a white blood cell count of 2500/uL and a rheumatoid factor titer of 1:4096. What is the likely finding on this patient's white blood cell differential count?
A. Basophilia
B. Lymphopenia
C. Granulocytopenia (Correct Answer)
D. Lymphocytosis
Explanation: ### Explanation
The clinical presentation of long-standing **Rheumatoid Arthritis (RA)**, **Splenomegaly**, and **Neutropenia** (implied by the low WBC count of 2500/uL) constitutes the classic triad of **Felty Syndrome** [1].
**1. Why Granulocytopenia is Correct:**
Felty Syndrome typically occurs in patients with long-standing, seropositive (high RF titer), and erosive RA [1]. The hallmark hematological finding is **granulocytopenia** (specifically **neutropenia**, defined as an absolute neutrophil count <2000/uL). The pathophysiology involves splenic sequestration of neutrophils and the presence of autoantibodies against neutrophils and granulocyte colony-stimulating factor (G-CSF). The patient’s leg ulcers are a common extra-articular manifestation associated with this syndrome [1].
**2. Why Incorrect Options are Wrong:**
* **Basophilia:** Associated with myeloproliferative disorders like Chronic Myeloid Leukemia (CML), not autoimmune inflammatory conditions.
* **Lymphopenia:** While seen in SLE or as a side effect of immunosuppressants (like steroids), it is not the defining hematologic feature of Felty Syndrome.
* **Lymphocytosis:** Specifically **Large Granular Lymphocyte (LGL) leukemia** is closely associated with Felty Syndrome (sharing the HLA-DR4 link), but the primary diagnostic criterion for Felty itself is the reduction of granulocytes, not an increase in lymphocytes.
**3. High-Yield Clinical Pearls for NEET-PG:**
* **Triad:** RA + Splenomegaly + Neutropenia [1].
* **Genetic Association:** Strongly linked with **HLA-DR4**.
* **Risk Factors:** High titers of Rheumatoid Factor (RF), extra-articular manifestations (nodules, vasculitis), and long-standing disease (>10 years) [1].
* **Complications:** Increased risk of recurrent bacterial infections and skin ulcers [1].
* **Treatment:** Management of the underlying RA (usually Methotrexate); G-CSF may be used for severe neutropenia.
Question 542: What crystalline material is characteristic of pseudogout?
A. Calcium pyrophosphate dihydrate (CPPD) (Correct Answer)
B. Urate crystals
C. Calcium carbonate crystals
D. Xanthine crystals
Explanation: Pseudogout, clinically known as **Calcium Pyrophosphate Deposition (CPPD) disease**, is a crystal-induced arthropathy caused by the deposition of **Calcium Pyrophosphate Dihydrate (CPPD)** crystals in the articular cartilage and periarticular tissues [1].
**Why Option A is Correct:**
The hallmark of pseudogout is the presence of CPPD crystals [1]. Under compensated polarized light microscopy, these crystals are characteristically **rhomboid-shaped** and exhibit **weak positive birefringence** (appearing blue when parallel to the compensator axis). This distinguishes them from the needle-shaped, negatively birefringent crystals of gout.
**Analysis of Incorrect Options:**
* **Option B (Urate crystals):** Monosodium urate (MSU) crystals are the cause of **Gout** [1]. They are needle-shaped and show strong negative birefringence.
* **Option C (Calcium carbonate):** These are not typically associated with inflammatory arthropathies; they are more commonly found in certain types of renal calculi.
* **Option D (Xanthine crystals):** These are extremely rare and occur in hereditary xanthinuria or as a side effect of high-dose allopurinol therapy [2], but they do not cause pseudogout.
**High-Yield Clinical Pearls for NEET-PG:**
* **Most Common Site:** The **knee** is the most frequently affected joint (unlike the 1st MTP joint in gout) [1].
* **Radiology:** Look for **Chondrocalcinosis** (linear calcification of articular cartilage or menisci) [1].
* **Associated Conditions:** Always screen for "The 4 H's": **H**yperparathyroidism, **H**emochromatosis, **H**ypomagnesemia, and **H**ypophosphatasia [1].
* **Treatment:** Acute attacks are managed with NSAIDs, colchicine, or intra-articular corticosteroids.
Question 543: A patient presents with gritty pain in the eye and joint pain after a leisure trip. What is the most probable diagnosis?
A. Reiter's syndrome (Correct Answer)
B. Behçet's syndrome
C. Sarcoidosis
D. Systemic Lupus Erythematosus (SLE)
Explanation: The clinical presentation points toward **Reiter’s Syndrome** (now more commonly referred to as **Reactive Arthritis**). This condition is characterized by a classic triad: **Nongonococcal urethritis, Conjunctivitis (gritty eye pain), and Arthritis [1].** The mention of a "leisure trip" is a high-yield clinical cue suggesting a preceding infection—either gastrointestinal (e.g., *Salmonella, Shigella, Campylobacter*) from contaminated food or urogenital (e.g., *Chlamydia*) from sexual exposure during travel [1].
**Why the other options are incorrect:**
* **Behçet’s Syndrome:** While it involves eyes and joints, it is primarily characterized by painful recurrent oral and genital ulcers and pathergy.
* **Sarcoidosis:** Can cause uveitis and arthritis (Lofgren’s syndrome), but typically presents with bilateral hilar lymphadenopathy and respiratory symptoms rather than a post-travel acute onset.
* **SLE:** A multisystem autoimmune disease that causes joint pain and ocular dryness (secondary Sjögren's), but it is more common in females and usually presents with a malar rash and constitutional symptoms.
**High-Yield Clinical Pearls for NEET-PG:**
* **Mnemonic:** "Can't see (conjunctivitis), can't pee (urethritis), can't climb a tree (arthritis)."
* **HLA Association:** Strongly associated with **HLA-B27** (positive in ~80% of cases) [1], [2].
* **Dermatological findings:** Look for **Keratoderma blennorrhagicum** (vesicular/pustular lesions on palms/soles) and **Circinate balanitis [1].**
* **Joint Involvement:** Typically an asymmetric oligoarthritis affecting the lower limbs (knees and ankles) [1].
Question 544: Which of the following organs is typically NOT affected by granulomatosis with polyangiitis (Wegener's granulomatosis)?
A. Liver (Correct Answer)
B. Lung
C. Kidney
D. Eye
Explanation: Explanation:
Granulomatosis with Polyangiitis (GPA), formerly known as Wegener’s Granulomatosis, is a systemic necrotizing vasculitis that primarily affects small to medium-sized vessels. It is characterized by a classic "triad" of involvement: the upper respiratory tract, the lower respiratory tract (lungs), and the kidneys.
Why Liver is the correct answer:
The liver is typically spared in GPA. While systemic vasculitis can theoretically affect any organ, clinically significant hepatic involvement is extremely rare and is not a characteristic feature of the disease. If a patient with suspected vasculitis presents with prominent liver involvement, clinicians should consider other diagnoses like Polyarteritis Nodosa (PAN).
Why other options are incorrect:
* Lung: Pulmonary involvement occurs in ~90% of patients. It typically presents as nodules, alveolar hemorrhage, or fixed infiltrates. Cavitation of these nodules is a classic radiologic finding.
* Kidney: Renal involvement (Glomerulonephritis) occurs in ~75-80% of cases. It characteristically presents as a Pauci-immune Crescentic Rapidly Progressive Glomerulonephritis (RPGN).
* Eye: Ocular manifestations occur in up to 50% of patients. Common findings include scleritis, episcleritis, and proptosis due to retro-orbital granulomatous inflammation.
NEET-PG High-Yield Pearls:
1. Serology: GPA is strongly associated with c-ANCA (anti-PR3 antibodies).
2. Upper Airway: Look for "Saddle nose deformity" due to nasal cartilage destruction and chronic sinusitis.
3. Biopsy Gold Standard: Shows necrotizing granulomatous inflammation.
4. Treatment: Induction with Corticosteroids + Cyclophosphamide (or Rituximab).
Question 545: Which statement regarding the renal involvement associated with SLE is true?
A. Clinically apparent renal disease occurs in 90% of affected persons
B. Interstitial nephritis is a rare finding on renal biopsy
C. Renal biopsy is not initially necessary in patients with deteriorating renal function and active urine sediment (Correct Answer)
D. Renal disease is uncommon in patients with higher anti-double stranded DNA antibodies
Explanation: In clinical practice, the management of SLE involves a high index of suspicion for Lupus Nephritis (LN). However, the statement provided in the options reflects a specific clinical nuance: if a patient with SLE presents with **rapidly deteriorating renal function** and an **active urine sediment** (hematuria, proteinuria, and cellular casts), the diagnosis of LN is clinically evident. While a biopsy is essential for **classification (ISN/RPS)** and determining the chronicity vs. activity index to guide long-term therapy, the immediate clinical priority is often the initiation of immunosuppressive therapy to prevent irreversible damage [1]. *Note: In most standard guidelines (like ACR/EULAR), a biopsy is strongly recommended for all patients with suspected LN, but in the context of this specific MCQ, it highlights that the clinical diagnosis can be presumptive based on sediment and function.*
**2. Why the Other Options are Wrong:**
* **Option A:** Clinically apparent renal disease occurs in approximately **50%** of SLE patients, although microscopic abnormalities may be found in up to 90% if every patient were biopsied.
* **Option B:** Interstitial nephritis is actually a **common** finding in SLE biopsies, often accompanying glomerular lesions. Its severity is a strong predictor of long-term renal outcome.
* **Option D:** Renal disease is **highly associated** with high titers of anti-dsDNA antibodies and low complement levels (C3, C4). These markers often fluctuate with the activity of lupus nephritis.
**High-Yield Clinical Pearls for NEET-PG:**
* **Most common cause of death** in early SLE is infection; in late SLE, it is accelerated atherosclerosis/MI and ESRD.
* **WHO/ISN/RPS Class IV (Diffuse Proliferative LN)** is the most common and most severe form.
* **Drug-induced Lupus** (Hydralazine, Procainamide) characteristically **spares the kidneys** and CNS.
* **Treatment:** Mycophenolate Mofetil (MMF) or Cyclophosphamide are the mainstays for induction in proliferative LN [2].
Question 546: A 30-year-old male patient presents with complaints of weakness in the right upper and both lower limbs for the last 4 months. He developed digital infarcts involving the 2nd and 3rd fingers on the right side and the 5th finger on the left side. On examination, BP was 160/140 mm Hg. All peripheral pulses were palpable, and there was asymmetrical neuropathy. Investigations showed Hb 12 gm%, TLC 12,000 per cu. mm, Platelets 4,30,000, and ESR 49 mm. Urine examination showed proteinuria and RBC 10-15/hpf with no casts. What is the most likely diagnosis?
A. Polyarteritis nodosa (Correct Answer)
B. Systemic lupus erythematosus
C. Wegener's granulomatosis
D. Mixed cryoglobulinemia
Explanation: ### **Explanation**
The clinical presentation is classic for **Polyarteritis Nodosa (PAN)**, a systemic necrotizing vasculitis of medium-sized arteries. [1]
**Why PAN is the correct diagnosis:**
1. **Mononeuritis Multiplex:** The "asymmetrical neuropathy" (weakness in three limbs) is a hallmark of PAN due to vasculitis of the *vasa nervorum*.
2. **Renal Involvement:** PAN typically causes **renovascular hypertension** (BP 160/140 mmHg) and renal ischemia. While it causes proteinuria and hematuria, a key feature is the **absence of RBC casts**, as PAN spares the glomeruli (it affects pre-glomerular vessels). [2]
3. **Digital Infarcts:** Medium-vessel involvement leads to cutaneous ischemia and gangrene.
4. **Systemic Inflammation:** Elevated ESR, TLC, and platelets are common. The fact that **all peripheral pulses are palpable** helps rule out Large Vessel Vasculitis (like Takayasu’s). [1]
**Why other options are incorrect:**
* **Systemic Lupus Erythematosus (SLE):** While it causes renal issues and neuropathy, the absence of RBC casts and the specific pattern of digital infarcts without malar rash or photosensitivity make PAN more likely.
* **Wegener’s Granulomatosis (GPA):** GPA is a small-vessel vasculitis that typically involves the upper/lower respiratory tract and causes **Glomerulonephritis** (which would show RBC casts). [2]
* **Mixed Cryoglobulinemia:** Usually associated with Hepatitis C, it presents with the triad of purpura, arthralgia, and weakness, but typically involves small vessels and shows low complement levels.
**High-Yield Clinical Pearls for NEET-PG:**
* **PAN is "Glomerulonephritis-sparing":** If a question mentions renal failure/hypertension *without* RBC casts, think PAN. [2]
* **Association:** Strongly associated with **Hepatitis B surface antigen (HBsAg)** in 10-30% of cases.
* **Angiography:** Shows characteristic **"string of pearls"** appearance (microaneurysms).
* **ANCA Status:** PAN is typically **ANCA-negative** (unlike GPA or MPA).
Question 547: A 58-year-old man has the sudden onset late one evening of severe pain in his left great toe. There is no history of trauma. On examination there is edema with erythema and pain on movement of the left 1st metatarsophalangeal joint, but there is no overlying skin ulceration. A joint aspirate is performed and on microscopic examination reveals numerous neutrophils. Over the next 3 weeks, he has two more similar episodes. On physical examination between these attacks, there is minimal loss of joint mobility. Which of the following laboratory test findings is most characteristic for his underlying disease process?
A. Hyperglycemia
B. Positive antinuclear antibody
C. Hyperuricemia (Correct Answer)
D. Hypercalcemia
Explanation: ### Explanation
**Correct Option: C. Hyperuricemia**
The clinical presentation describes a classic case of **Acute Gouty Arthritis** (Podagra). The sudden onset of severe pain, erythema, and edema of the 1st metatarsophalangeal (MTP) joint, especially in an older male, is the hallmark of gout. The presence of numerous neutrophils in the joint aspirate indicates an acute inflammatory response triggered by the deposition of **monosodium urate (MSU) crystals**.
The underlying metabolic abnormality in gout is **hyperuricemia** (serum urate >6.8 mg/dL), which leads to the supersaturation of uric acid in synovial fluid. While an acute attack can occur with normal serum urate levels, chronic hyperuricemia is the fundamental biochemical prerequisite for the disease process.
**Why other options are incorrect:**
* **A. Hyperglycemia:** While gout is often associated with metabolic syndrome and diabetes, hyperglycemia is not the diagnostic or characteristic laboratory finding for the joint pathology itself.
* **B. Positive Antinuclear Antibody (ANA):** ANA is a screening test for systemic autoimmune diseases like Systemic Lupus Erythematosus (SLE). SLE typically presents with symmetric polyarthritis, not isolated podagra.
* **C. Hypercalcemia:** This is associated with **Pseudogout** (Calcium Pyrophosphate Deposition Disease), which more commonly affects the knee or wrist and involves rhomboid-shaped, positively birefringent crystals.
**Clinical Pearls for NEET-PG:**
* **Gold Standard Diagnosis:** Polarized light microscopy of synovial fluid showing **needle-shaped, negatively birefringent crystals** (yellow when parallel to the slow axis).
* **Radiology:** "Punched-out" erosions with overhanging edges (**Martel’s sign**) are seen in chronic tophaceous gout.
* **Acute Management:** NSAIDs (first-line), Colchicine, or Corticosteroids.
* **Chronic Management:** Xanthine oxidase inhibitors (Allopurinol, Febuxostat). *Note: Never start urate-lowering therapy during an acute attack as it may worsen the flare.*
Question 548: A 40-year-old obese man presents with intense pain in his left first metatarsophalangeal (MTP) joint for the past few hours. He has no history of trauma, fever, chills, and no previous similar episode. He has no history of renal disease or diabetes, though he has been told he is "prediabetic." He does not recall any recent skin infections and no family members have had any reported staphylococcal infection. On examination, he has a swollen, red, warm, tender first MTP joint on the left. Uric acid level is 9 mg/dL; serum creatinine is normal. What is the best treatment approach for this patient?
A. Start allopurinol immediately and titrate for a uric acid level below 6 mg/dL. Add colchicine if this is not effective within the first 24 hours.
B. Begin prednisone until symptoms subside.
C. Begin indomethacin. As the patient improves, reduce the dose to minimize gastrointestinal side effects. (Correct Answer)
D. Prescribe a narcotic until pain is under control.
Explanation: ### **Explanation**
The clinical presentation—acute onset of intense pain, swelling, and erythema in the first metatarsophalangeal (MTP) joint (podagra) in an obese male with hyperuricemia—is classic for **Acute Gouty Arthritis** [2].
**1. Why Option C is Correct:**
The primary goal in acute gout is rapid inflammation control. **Non-steroidal anti-inflammatory drugs (NSAIDs)**, such as indomethacin, are the first-line treatment for patients without contraindications (like renal failure or peptic ulcers). Treatment should be started at maximum doses and tapered as symptoms resolve to minimize side effects. Since the patient has normal creatinine and no history of GI bleeds, NSAIDs are the most appropriate initial step.
**2. Why Other Options are Incorrect:**
* **Option A:** **Allopurinol (Urate-Lowering Therapy - ULT)** should **never** be started during an acute attack [1]. Sudden changes in serum uric acid levels can cause mobilization of urate crystals from tissues, potentially worsening or prolonging the acute flare. ULT is indicated only after the acute episode has fully resolved (usually 2 weeks later).
* **Option B:** While corticosteroids (like prednisone) are effective, they are typically reserved for patients who cannot tolerate NSAIDs or colchicine, or those with polyarticular gout.
* **Option D:** Narcotics provide analgesia but do not address the underlying inflammatory process. They are not standard therapy for gout.
**3. NEET-PG High-Yield Pearls:**
* **Gold Standard Diagnosis:** Polarized light microscopy of synovial fluid showing **negatively birefringent, needle-shaped crystals** .
* **Uric Acid Levels:** Serum uric acid can be **normal** during an acute attack (due to cytokines increasing renal excretion). A high level (9 mg/dL) supports the diagnosis but is not definitive.
* **First-line agents:** NSAIDs (Indomethacin/Naproxen), Colchicine, or Corticosteroids.
* **Target Urate Level:** Once on ULT, the goal is to maintain serum uric acid **<6 mg/dL** (or <5 mg/dL in tophaceous gout) [1].
Question 549: A 22-year-old female Asian immigrant presents with complaints of malaise, fever, arm pain, loss of appetite, and visual problems. Her mother states that she fainted one week ago. The physician cannot palpate the patient's lower extremity pulses and notes that the radial pulses are weak. The erythrocyte sedimentation rate (ESR) is elevated. Which of the following is the most likely diagnosis?
A. Buerger's disease
B. Kawasaki's disease
C. Takayasu's arteritis (Correct Answer)
D. Thrombophlebitis
Explanation: **Explanation:**
The clinical presentation is classic for **Takayasu’s Arteritis**, also known as "Pulseless Disease." This is a chronic, large-vessel vasculitis that primarily involves the aorta and its main branches. Systemic vasculitis should be considered in any patient with fever, weight loss, and fatigue alongside raised inflammatory markers [1].
**Why Takayasu’s Arteritis is correct:**
1. **Demographics:** It predominantly affects young females (<40 years) of Asian descent.
2. **Clinical Features:** The patient exhibits the "triphasic" progression: an initial systemic phase (fever, malaise, weight loss) followed by a vascular phase. The "weak radial pulses" and "absent lower extremity pulses" indicate stenotic lesions in the aorta or its branches.
3. **Neurological/Visual symptoms:** Syncope (fainting) and visual disturbances occur due to carotid or vertebral artery involvement (subclavian steal syndrome or carotid insufficiency).
4. **Laboratory:** An elevated ESR is a hallmark of the active inflammatory phase [1].
**Why other options are incorrect:**
* **Buerger’s Disease (Thromboangiitis obliterans):** Affects small-to-medium vessels in young male smokers; presents with digital gangrene/claudication, not systemic large-vessel failure.
* **Kawasaki’s Disease:** A medium-vessel vasculitis seen in children (<5 years) [2]. It presents with "CRASH and Burn" symptoms (Conjunctivitis, Rash, Adenopathy, Strawberry tongue, Hand/foot edema, and Fever) and mainly affects the coronary vessels [2].
* **Thrombophlebitis:** Inflammation of a vein caused by a blood clot; it does not cause systemic pulse deficits or large-vessel ischemia.
**High-Yield NEET-PG Pearls:**
* **Gold Standard Diagnosis:** Conventional Angiography (shows "string of pearls" or tapered narrowing).
* **Classification:** It is a **Large Vessel Vasculitis** (along with Giant Cell Arteritis).
* **Key Association:** Often involves the **subclavian artery**, leading to blood pressure discrepancies between arms (>10 mmHg).
* **Treatment:** Glucocorticoids are the first-line therapy.
Question 550: A 27-year-old man presents with a history of low back pain and stiffness. After several months of mild symptoms, he experiences more severe stiffness at night and hip pain. Physical examination reveals paravertebral muscle tenderness and limited lumbar spine flexion. X-ray of the lumbar spine shows sacroiliitis. In addition to recommending physiotherapy and exercise, what is the most appropriate next step in management?
A. NSAID therapy (Correct Answer)
B. Phenylbutazone
C. Azathioprine
D. Acetaminophen
Explanation: **Explanation:**
The clinical presentation of a young male with chronic low back pain, nocturnal stiffness, hip involvement, and radiographic evidence of sacroiliitis is classic for **Ankylosing Spondylitis (AS)**, a prototype of Seronegative Spondyloarthropathies [3].
**1. Why NSAIDs are the Correct Choice:**
NSAIDs are the **first-line pharmacological treatment** for Ankylosing Spondylitis. Unlike in many other mechanical back pains, NSAIDs in AS not only provide symptomatic relief for pain and stiffness but may also slow radiographic progression (syndesmophyte formation) when used continuously. They help improve spinal mobility, allowing the patient to engage effectively in physiotherapy, which is the cornerstone of non-pharmacological management.
**2. Why Other Options are Incorrect:**
* **B. Phenylbutazone:** While effective for AS, it is rarely used due to its severe side effect profile, specifically the risk of **aplastic anemia** and agranulocytosis. It is considered a last resort.
* **C. Azathioprine:** This is an immunosuppressant not indicated for the axial symptoms of AS. Conventional DMARDs (like Sulfasalazine or Methotrexate) may be used for peripheral arthritis in AS but have **no proven efficacy** for spinal/axial disease.
* **D. Acetaminophen:** While it provides mild analgesia, it lacks the anti-inflammatory properties required to manage the underlying enthesitis and synovitis characteristic of AS [3].
**Clinical Pearls for NEET-PG:**
* **Modified New York Criteria:** Used for diagnosis; requires radiographic sacroiliitis plus clinical criteria (limited spinal mobility/chest expansion) [1].
* **HLA-B27:** Strongly associated (>90% of cases) but not diagnostic on its own [3].
* **Schober’s Test:** Used to quantify limited lumbar flexion.
* **Refractory Cases:** If two different NSAIDs fail over 4 weeks, the next step is **TNF-alpha inhibitors** (e.g., Etanercept, Infliximab) or IL-17 inhibitors (Secukinumab) [2].
