Rheumatology and Immunology — MCQs

A 28-year-old man presents with symptoms of frequent bowel movements, crampy abdominal pain, and the passage of mucus. There is no history of bloody diarrhea, but recently, he developed joint discomfort in his hands, knees, and back. On examination, he is thin, and his abdomen is soft with voluntary guarding in the left lower quadrant. His joints are not actively inflamed and there is an asymmetric distribution. Which of the following is the most likely diagnosis?

Q119Easy

Sausage digit is seen in which of the following conditions?

Q120Easy

Etanercept is a biological disease-modifying agent used in the management of rheumatoid arthritis. What is its mechanism of action?

Rheumatology and Immunology Indian Medical PG Practice Questions and MCQs

Question 111: Which of the following statements is NOT true regarding rheumatic pleural effusion?

A. pH less than 7.2
B. LDH greater than 700
C. Glucose greater than 50 (Correct Answer)
D. ADH level >50mg/dl

Explanation: ### Explanation Rheumatoid Pleural Effusion is a classic example of an **exudative effusion** with unique biochemical markers. The hallmark of this condition is an **extremely low glucose level**, typically **less than 30 mg/dL** (and often <15 mg/dL). #### Why Option C is the Correct Answer (The "False" Statement) In rheumatoid pleurisy, glucose levels are characteristically very low due to a combination of active consumption by the inflamed pleura and a block in the transport of glucose from the blood into the pleural space. Therefore, the statement "Glucose greater than 50" is incorrect. #### Analysis of Other Options * **A. pH less than 7.2:** True. Rheumatoid effusions are highly acidic, often with a pH below 7.0, reflecting intense local inflammation [1]. * **B. LDH greater than 700:** True. These effusions are characterized by very high Lactate Dehydrogenase (LDH) levels, frequently exceeding 700–1000 IU/L, indicating significant cellular turnover and pleural inflammation. * **D. ADA level >50 U/L:** True. While Adenosine Deaminase (ADA) is a classic marker for Tuberculosis, it is also frequently elevated (often >50 U/L) in Rheumatoid Arthritis and Empyema, which can lead to diagnostic confusion. #### NEET-PG High-Yield Pearls * **Low Glucose Triad:** The three main causes of pleural fluid glucose <30 mg/dL are **Rheumatoid Arthritis**, **Empyema**, and **Malignancy**. * **Complement Levels:** Rheumatoid effusions typically show **low complement levels** (C3, C4, and CH50) compared to serum levels. * **Cytology:** Look for "gritty" appearance or "tadpole cells" (elongated macrophages) on cytology. * **Epidemiology:** Interestingly, while RA is more common in women, rheumatoid pleural effusions are more common in **older men** with rheumatoid nodules [2].

Question 112: All may be associated with Sicca syndrome except?

A. Scleroderma
B. Rheumatoid arthritis
C. Midline granuloma (Correct Answer)
D. Lymphadenopathy

Explanation: **Explanation:** **Sicca Syndrome** (Primary Sjögren’s Syndrome) is a chronic autoimmune disorder characterized by lymphocytic infiltration of exocrine glands, primarily leading to xerophthalmia (dry eyes) and xerostomia (dry mouth). It can occur alone or secondary to other connective tissue diseases. **Why Midline Granuloma is the correct answer:** Midline granuloma (often referring to **Lethal Midline Granuloma** or Granulomatosis with Polyangiitis) is a destructive inflammatory process involving the nasal passage and paranasal sinuses. It is characterized by necrotizing granulomas and vasculitis. It does not typically involve the lymphocytic infiltration of salivary or lacrimal glands and is therefore not associated with Sicca syndrome. **Analysis of other options:** * **Scleroderma (Systemic Sclerosis):** Frequently associated with secondary Sjögren’s syndrome due to glandular fibrosis and autoimmune destruction. * **Rheumatoid Arthritis (RA):** This is the **most common** autoimmune disease associated with secondary Sjögren’s syndrome (occurring in ~30% of RA patients) [1]. * **Lymphadenopathy:** Patients with Sjögren’s syndrome often exhibit lymph node enlargement. Crucially, they have a **40-fold increased risk** of developing B-cell Non-Hodgkin Lymphoma (MALToma), making lymphadenopathy a significant clinical finding to monitor. **High-Yield Clinical Pearls for NEET-PG:** * **Antibodies:** Anti-Ro (SS-A) and Anti-La (SS-B) are the hallmark markers. * **Diagnosis:** Schirmer’s test (measures tear production) and Lip biopsy (showing focal lymphocytic sialadenitis) are gold standards. * **Extraglandular manifestation:** Raynaud’s phenomenon and cutaneous vasculitis are common. * **Highest Risk:** Sjögren’s syndrome carries the highest risk of lymphoma among all autoimmune diseases.

Question 113: Which of the following is NOT a feature of seronegative spondyloarthropathy?

A. Strong association with HLA B27
B. Negative Rheumatoid Factor
C. Symmetrical Polyarthritis (Correct Answer)
D. Enthesitis

Explanation: **Explanation:** Seronegative spondyloarthropathies (SpA) are a group of inflammatory diseases (including Ankylosing Spondylitis, Psoriatic Arthritis, Reactive Arthritis, and Enteropathic Arthritis) characterized by the absence of Rheumatoid Factor (RF) and distinct clinical features [1]. **Why "Symmetrical Polyarthritis" is the correct answer:** Seronegative spondyloarthropathies typically present as **Asymmetrical Oligoarthritis** (involving <5 joints, often in the lower limbs) [1]. In contrast, **Symmetrical Polyarthritis** is the hallmark of Rheumatoid Arthritis [2]. While Psoriatic Arthritis can occasionally present with a symmetrical pattern, it is not a defining or universal feature of the SpA group. **Analysis of Incorrect Options:** * **A. Strong association with HLA B27:** This is a classic feature. HLA-B27 is most strongly associated with Ankylosing Spondylitis (>90% of cases) and is a key diagnostic marker for the entire group [1]. * **B. Negative Rheumatoid Factor:** By definition, these conditions are "seronegative," meaning RF and Anti-CCP antibodies are typically absent [1]. * **D. Enthesitis:** This is a pathognomonic feature of SpA. It refers to inflammation at the site where tendons or ligaments insert into bone (e.g., Achilles tendonitis or plantar fasciitis) [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Common Features (PEAR):** **P**soriatic arthritis, **E**nteropathic arthritis, **A**nkylosing spondylitis, **R**eactive arthritis. * **Axial Involvement:** Sacroiliitis and spondylitis (bamboo spine) are characteristic [1]. * **Extra-articular manifestations:** Acute anterior uveitis is the most common extra-articular finding [1]. * **Dactylitis:** "Sausage digits" are frequently seen, especially in Psoriatic and Reactive arthritis.

Question 114: Which of the following statements about fibromyalgia is true?

A. More common in males
B. Sleep EEG studies have shown disruption in REM sleep
C. Increased cortisol response to stress
D. SPECT studies have shown reduced blood flow to the thalamus (Correct Answer)

Explanation: Explanation: Fibromyalgia is a chronic pain syndrome characterized by widespread musculoskeletal pain, fatigue, and sleep disturbances [1]. It is considered a disorder of central pain processing (central sensitization). Why Option D is Correct: Functional neuroimaging studies, including SPECT (Single-Photon Emission Computed Toxicity) and functional MRI, have consistently demonstrated altered pain processing in the brain [1]. Specifically, patients with fibromyalgia show reduced regional cerebral blood flow (hypoperfusion) in the thalamus and the caudate nucleus [1]. Since the thalamus acts as the "gatekeeper" for sensory input, this dysfunction contributes to the lowered pain threshold (allodynia). Analysis of Incorrect Options: * Option A: Fibromyalgia is significantly more common in females (ratio approx. 7:1 to 9:1), typically presenting between ages 20 and 50. * Option B: Sleep studies (Polysomnography/EEG) show a characteristic disruption in Stage 4 Non-REM sleep, specifically the "alpha-delta sleep" pattern (intrusion of alpha waves into deep delta sleep), rather than REM sleep disruption [1]. * Option C: Fibromyalgia is associated with a blunted (decreased) cortisol response to stress due to mild secondary adrenal insufficiency or hypothalamic-pituitary-adrenal (HPA) axis dysregulation [1], not an increased response. High-Yield Clinical Pearls for NEET-PG: * Diagnosis: Primarily clinical [1]. The 2010/2016 ACR criteria focus on the Widespread Pain Index (WPI) and Symptom Severity (SS) scale, moving away from the older "11 of 18 tender points" requirement. * Lab Findings: All inflammatory markers (ESR, CRP) and muscle enzymes (CPK) are characteristically normal [2]. * Management: First-line treatment involves patient education and aerobic exercise [2]. Pharmacotherapy includes Amitriptyline (TCA), Duloxetine (SNRI), or Pregabalin (Gabapentinoid).

Question 115: A 14-year-old girl on exposure to cold has pallor of extremities followed by pain and cyanosis. In later life, she is prone to develop which of the following conditions?

A. Systemic lupus erythematosus
B. Scleroderma (Correct Answer)
C. Rheumatoid arthritis
D. Histiocytosis

Explanation: ### Explanation **Concept Overview** The clinical presentation describes **Raynaud’s Phenomenon**, characterized by a triphasic color change in response to cold or stress: **Pallor** (vasoconstriction), **Cyanosis** (deoxygenation), and **Rubor** (reperfusion/pain). When Raynaud’s occurs in a young patient without an underlying cause, it is "Primary Raynaud’s Disease." However, when it precedes or accompanies a systemic disease, it is "Secondary Raynaud’s." **Why Scleroderma is Correct** Raynaud’s phenomenon is the **earliest and most common clinical manifestation** of Systemic Sclerosis (Scleroderma), occurring in over 95% of patients. It often precedes other symptoms (like skin thickening or visceral involvement) by years, especially in the Limited Cutaneous subtype (CREST syndrome) [1]. In a young female presenting with these symptoms, the risk of progression to a connective tissue disorder—specifically Scleroderma—is high. **Analysis of Incorrect Options** * **A. Systemic Lupus Erythematosus (SLE):** While Raynaud’s occurs in about 30% of SLE patients, it is rarely the presenting or dominant feature compared to Scleroderma. * **C. Rheumatoid Arthritis:** Raynaud’s is not a classic or defining feature of RA; RA primarily presents with symmetrical small joint inflammatory arthritis. * **D. Histiocytosis:** This is a group of rare disorders involving abnormal proliferation of Langerhans cells; it has no clinical association with cold-induced vasospasm. **High-Yield Clinical Pearls for NEET-PG** * **Primary vs. Secondary:** Primary Raynaud’s usually has normal nailfold capillaries and negative ANA. Secondary Raynaud’s (Scleroderma) shows **dilated/tortuous nailfold capillary loops** and positive ANA/Anti-Scl-70/Anti-centromere antibodies [1]. * **CREST Syndrome:** Raynaud’s is the "R" in CREST (Calcinosis, Raynaud’s, Esophageal dysmotility, Sclerodactyly, Telangiectasia). * **Drug of Choice:** Calcium Channel Blockers (e.g., **Nifedipine**) are the first-line treatment for Raynaud’s.

Question 116: Churg-Strauss syndrome involves which of the following, except?

A. Lungs
B. Kidneys
C. Small blood vessels
D. Heart (Correct Answer)

Explanation: **Explanation:** **Churg-Strauss Syndrome (now known as Eosinophilic Granulomatosis with Polyangiitis - EGPA)** is a multisystem disorder characterized by necrotizing vasculitis of small and medium-sized vessels, extravascular granulomas, and hypereosinophilia. **Why Option D (Heart) is the correct answer (in the context of this specific question):** While EGPA *can* involve the heart (causing myocarditis or coronary vasculitis), it is classically defined as a **small-vessel vasculitis** that primarily targets the respiratory tract and skin [1]. In many standardized medical examinations, when asked to identify the "exception" among classic features, the heart is often singled out because, although it is the leading cause of mortality in EGPA, it is not a mandatory diagnostic criterion like pulmonary or vascular involvement. *Note: In clinical practice, cardiac involvement is common, but for the purpose of this specific question, the other three options represent the core, defining pathological sites.* **Analysis of other options:** * **A. Lungs:** The most common site of involvement. Patients typically present with severe asthma, allergic rhinitis, and transient pulmonary infiltrates [2]. * **B. Kidneys:** Though less frequent than in GPA (Wegener’s), pauci-immune glomerulonephritis occurs in approximately 25% of cases. * **C. Small blood vessels:** By definition, EGPA is a small-vessel vasculitis (ANCA-associated) [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Triad of EGPA:** Asthma, Peripheral Eosinophilia, and Necrotizing Vasculitis [1]. * **ANCA Status:** p-ANCA (anti-MPO) is positive in about 40-50% of cases. * **Key Diagnostic Feature:** Presence of eosinophilic tissue infiltrates and extravascular granulomas [1]. * **Most common cause of death:** Myocardial infarction or heart failure due to eosinophilic myocarditis. * **Distinguishing factor:** Unlike Wegener’s (GPA), EGPA is strongly associated with **asthma** and **eosinophilia** [2].

Question 117: Mononeuritis multiplex is a major presenting feature of which of the following conditions?

A. Systemic necrotising vasculitis (Correct Answer)
B. Wagner's granulomatosis
C. Hypersensitivity vasculitis
D. Mucocutaneous lymphnode syndrome

Explanation: **Explanation:** **Mononeuritis multiplex** is a clinical syndrome characterized by simultaneous or sequential involvement of non-contiguous nerve trunks (asymmetrical neuropathy). It is most commonly caused by **vasculitic neuropathy**, where inflammation of the *vasa nervorum* (small vessels supplying nerves) leads to ischemic infarction of the nerves [1]. **1. Why Systemic Necrotizing Vasculitis is Correct:** Systemic necrotizing vasculitides, particularly **Polyarteritis Nodosa (PAN)**, are the classic prototypes for mononeuritis multiplex. In PAN, the necrotizing inflammation of medium and small-sized arteries leads to nerve ischemia in up to 70% of cases. It typically presents with sudden-onset foot drop or wrist drop [3]. **2. Why the other options are incorrect:** * **Wegener’s Granulomatosis (GPA):** While it can cause mononeuritis multiplex, its hallmark features are the triad of upper respiratory tract involvement (sinusitis), lower respiratory tract (lung nodules/hemoptysis), and glomerulonephritis. It is less "classically" associated with mononeuritis as the *major* presenting feature compared to PAN. * **Hypersensitivity Vasculitis:** This primarily affects small vessels (venules) and typically manifests as **palpable purpura** confined to the skin. It rarely involves the vasa nervorum to a degree that causes mononeuritis multiplex [2]. * **Mucocutaneous Lymph Node Syndrome (Kawasaki Disease):** This is a pediatric vasculitis characterized by high fever, conjunctivitis, strawberry tongue, and coronary artery aneurysms [2]. Neurological involvement is rare. **Clinical Pearls for NEET-PG:** * **Most common cause of Mononeuritis Multiplex:** Diabetes Mellitus (metabolic), but **Vasculitis** is the most common *inflammatory* cause [4]. * **Gold Standard Diagnosis:** Nerve biopsy (usually the sural nerve) showing transmural inflammation and fibrinoid necrosis. * **PAN Association:** Strongly associated with **Hepatitis B** (HBsAg positivity). * **Rule of thumb:** If a patient presents with "Foot drop + Fever + Weight loss," think Polyarteritis Nodosa [1].

Question 118: A 28-year-old man presents with symptoms of frequent bowel movements, crampy abdominal pain, and the passage of mucus. There is no history of bloody diarrhea, but recently, he developed joint discomfort in his hands, knees, and back. On examination, he is thin, and his abdomen is soft with voluntary guarding in the left lower quadrant. His joints are not actively inflamed and there is an asymmetric distribution. Which of the following is the most likely diagnosis?

A. Lymphoma of the bowel
B. Amyloid infiltration
C. Chronic pancreatitis
D. Ulcerative colitis (Correct Answer)

Explanation: ### Explanation **1. Why Ulcerative Colitis (UC) is the Correct Answer:** The patient presents with classic symptoms of **Inflammatory Bowel Disease (IBD)**: chronic diarrhea, crampy abdominal pain, and mucus passage [1]. The key to this question lies in the **extraintestinal manifestations (EIMs)**. Joint involvement is the most common EIM of IBD, occurring in approximately 25% of patients [2]. The description of joint discomfort in the hands, knees, and back suggests two patterns of arthritis associated with UC: * **Peripheral Arthritis:** Often asymmetric, involving large joints (knees) or small joints (hands). Type I is pauciarticular (large joints), while Type II is polyarticular (small joints) [2]. * **Axial Involvement:** Sacroiliitis or Ankylosing Spondylitis (back pain), which is strongly associated with the **HLA-B27** marker [2]. While bloody diarrhea is common in UC, its absence does not rule out the diagnosis, especially in milder or proximal presentations. **2. Why Other Options are Incorrect:** * **A. Lymphoma of the bowel:** While it can cause abdominal pain and weight loss, it does not typically present with a migratory or asymmetric inflammatory-type arthritis. * **B. Amyloid infiltration:** Secondary amyloidosis (AA) can occur as a complication of chronic inflammation, but it usually presents with malabsorption or renal failure, not primary joint symptoms and mucus-rich diarrhea. * **C. Chronic pancreatitis:** This typically presents with steatorrhea (fatty stools) and severe epigastric pain radiating to the back, rather than lower abdominal guarding and peripheral arthritis [3]. **3. NEET-PG High-Yield Pearls:** * **Arthritis in IBD:** Peripheral arthritis activity often parallels the bowel disease activity (especially Type I), whereas axial involvement (Ankylosing Spondylitis) runs a course **independent** of the bowel symptoms [2]. * **Skin Findings:** Look for *Pyoderma gangrenosum* (more common in UC) and *Erythema nodosum* (more common in Crohn’s) [2]. * **HLA Association:** HLA-B27 is linked to the axial arthropathy seen in IBD patients [2]. * **P-ANCA:** Often positive in Ulcerative Colitis (60-70%), while ASCA is more specific for Crohn’s Disease.

Question 119: Sausage digit is seen in which of the following conditions?

A. Rheumatoid arthritis
B. Juvenile idiopathic arthritis
C. Enteropathic arthritis
D. Psoriatic arthritis (Correct Answer)

Explanation: **Explanation:** **Sausage digit**, clinically known as **Dactylitis**, is the hallmark feature of **Sero-negative Spondyloarthropathies (SpA)**. It represents diffuse swelling of an entire finger or toe due to inflammation of the small joints and, more importantly, the surrounding tendons and their sheaths (tenosynovitis) [1]. **Why Psoriatic Arthritis (PsA) is correct:** PsA is the most common cause of dactylitis, occurring in approximately 30–50% of patients. Unlike the localized joint swelling seen in Rheumatoid Arthritis, dactylitis involves the entire digit, giving it a "sausage-like" appearance [1]. It is a key diagnostic criterion in the CASPAR criteria for PsA. **Why other options are incorrect:** * **Rheumatoid Arthritis (RA):** RA typically causes symmetrical, localized swelling of the MCP and PIP joints (spindle-shaped fingers) [2]. It does not involve the entire digit or the tendon sheaths in a way that produces dactylitis. * **Juvenile Idiopathic Arthritis (JIA):** While some subtypes (like Enthesitis-related JIA) can show dactylitis, it is not the classic or defining feature compared to PsA. * **Enteropathic Arthritis:** While it is a Spondyloarthropathy, dactylitis is much rarer here than in PsA or Reactive Arthritis [1]. **High-Yield Clinical Pearls for NEET-PG:** 1. **Differential Diagnosis of Dactylitis:** Psoriatic Arthritis (most common), Reactive Arthritis (Reiter’s), Ankylosing Spondylitis, Sickle Cell Anemia (Hand-foot syndrome), and Sarcoidosis. 2. **Radiology:** Look for the "Pencil-in-cup" deformity in PsA [1]. 3. **Nail Changes:** Pitting of nails and onycholysis in a patient with joint pain strongly suggests PsA [1]. 4. **Symmetry:** PsA is typically asymmetric, whereas RA is symmetric [2].

Question 120: Etanercept is a biological disease-modifying agent used in the management of rheumatoid arthritis. What is its mechanism of action?

A. TNF alpha blockade (Correct Answer)
B. COX2 inhibition
C. IL 6 inhibition
D. Stabilization of mast cells

Explanation: **Explanation:** **Etanercept** is a biological Disease-Modifying Antirheumatic Drug (bDMARD) used primarily in Rheumatoid Arthritis (RA), Ankylosing Spondylitis, and Psoriasis [1]. 1. **Mechanism of Action (Option A):** Etanercept is a **soluble TNF-receptor fusion protein**. It consists of two extracellular domains of the human p75 TNF receptor linked to the Fc portion of human IgG1 [1]. It acts as a "decoy receptor," binding to both **TNF-α and TNF-β** (lymphotoxin-α) in the circulation, thereby preventing them from interacting with cell-bound receptors. This neutralizes the pro-inflammatory cascade driven by TNF [4]. 2. **Analysis of Incorrect Options:** * **Option B (COX2 inhibition):** This is the mechanism of NSAIDs like Celecoxib. They provide symptomatic relief but do not modify the disease course [3]. * **Option C (IL-6 inhibition):** This describes **Tocilizumab** and Sarilumab. While also used in RA, they target a different cytokine pathway [4]. * **Option D (Mast cell stabilization):** This is the mechanism of drugs like Cromolyn sodium, used in asthma and allergic rhinitis, not RA. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic:** "Etanercept **S**epts (Accepts) TNF." (It is a receptor, unlike Infliximab/Adalimumab which are monoclonal antibodies) [1]. * **Screening:** Before starting any TNF inhibitor, patients **must** be screened for **Latent Tuberculosis** (via TST or IGRA) and Hepatitis B, as these drugs can cause reactivation. * **Side Effects:** Increased risk of serious infections [1], injection site reactions, and potential worsening of Heart Failure. * **Drug of Choice:** While Methotrexate remains the initial DMARD of choice [2], Etanercept is often added in refractory cases [1].

Practice by Chapter

Rheumatoid Arthritis

Practice Questions

Spondyloarthropathies

Practice Questions

Systemic Lupus Erythematosus

Practice Questions

Vasculitis Syndromes

Practice Questions

Scleroderma and Related Disorders

Practice Questions

Inflammatory Myopathies

Practice Questions

Crystal Arthropathies

Practice Questions

Osteoarthritis

Practice Questions

Primary Immunodeficiency Disorders

Practice Questions

Autoinflammatory Syndromes

Practice Questions

Sjögren's Syndrome

Practice Questions

Antiphospholipid Syndrome

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free