Autoimmune Disorders — MCQs

10 questions

A 10-year-old boy presents with fever, joint pain, and a lesion over his hand, as seen in the image below. Which of the following is the clinical finding, and what is the likely diagnosis?

Most strongly associated with rheumatoid arthritis among the following is?

A young girl is admitted with joint pains and butterfly rash and positive urine proteinuria. The best test for her diagnosis is ?

Polyarticular onset JRA involves more than how many joints?

An 8-year-old child presents with hematuria 5 days after a throat infection. What is the most likely diagnosis?

A 6-year-old child with abdominal pain and a rash is shown. Comment on the diagnosis?

A 1-year-old unimmunised child with HbsAg positivity is having following skin lesions. What is the diagnosis?

Which of the following statements are correct regarding the management of gastrointestinal bleeding in children? I. Somatostatin or octreotide infusion should be given for at least 7 days after stoppage of initial bleeding to prevent rebleeding II. Endoscopic Sclerotherapy (EST) involves endoscopic injection of N -butyl-2-cyanoacrylate or iso-butyl-2-cyanoacrylate III. EST has upto 90 % efficacy in controlling acute bleeding IV. Following an episode of acute variceal bleeding, all patients should receive secondary prophylaxis to prevent rebleeding Select the answer using the code given below :

Q9Easy

What is a characteristic feature of Systemic Juvenile Idiopathic Arthritis?

Q10Medium

A child presents with delayed separation of the umbilical cord, leukocytosis, Down syndrome, and recurrent infections. What is the most likely diagnosis?

Autoimmune Disorders Indian Medical PG Practice Questions and MCQs

Question 1: A 10-year-old boy presents with fever, joint pain, and a lesion over his hand, as seen in the image below. Which of the following is the clinical finding, and what is the likely diagnosis?

A. Malar rash - Systemic lupus erythematosus
B. Heliotrope rash - Dermatomyositis
C. Erythema multiforme - Stevens-Johnson syndrome
D. Gottron's papules - Juvenile dermatomyositis (Correct Answer)

Explanation: ***Gottron's papules - Juvenile dermatomyositis*** - The image clearly displays **Gottron's papules**, which are **erythematous, scaling papules** symmetrically distributed over the **dorsal aspects of the interphalangeal joints** (MCP and PIP joints). - The clinical presentation of a 10-year-old boy with **fever, joint pain**, and these characteristic skin lesions is highly indicative of **juvenile dermatomyositis (JDM)**, an inflammatory myopathy. *Malar rash - Systemic lupus erythematosus* - A **malar rash** is a common finding in **systemic lupus erythematosus (SLE)**, but it typically presents as an **erythematous rash over the cheeks and bridge of the nose**, sparing the nasolabial folds, and does not exhibit the papular, scaly appearance over the knuckles seen in the image. - While SLE can cause fever and joint pain, the specific skin lesion depicted is not consistent with a malar rash. *Heliotrope rash - Dermatomyositis* - A **heliotrope rash** is another classic skin manifestation of **dermatomyositis**, characterized by a **purplish discoloration around the eyelids**, often accompanied by periorbital edema. - This is distinct from the lesions shown on the knuckles, which are diagnostic of Gottron's papules, not a heliotrope rash. *Erythema multiforme - Stevens-Johnson syndrome* - **Erythema multiforme** is characterized by **targetoid lesions** with concentric rings, often appearing acutely in response to infections or medications. - **Stevens-Johnson syndrome (SJS)** is a severe form of erythema multiforme, involving extensive epidermal detachment and mucosal involvement, which does not match the chronic-appearing, papular lesions on the knuckles in the image.

Question 2: Most strongly associated with rheumatoid arthritis among the following is?

A. HLA B27
B. HLA DR4 (Correct Answer)
C. HLA DQ1
D. HLA DR8

Explanation: ***HLA DR4*** - **HLA-DR4** is the **MHC Class II allele** most strongly associated with an increased risk and severity of **rheumatoid arthritis (RA)**. - It is thought to contribute to RA pathogenesis by presenting specific peptides that activate **auto-reactive T cells**, initiating the autoimmune response. *HLA B27* - **HLA-B27** is primarily associated with **seronegative spondyloarthropathies**, such as **ankylosing spondylitis** and **reactive arthritis**. - It has no significant association with **rheumatoid arthritis**. *HLA DQ1* - While a variety of **HLA-DQ alleles** are involved in autoimmune diseases, **HLA-DQ1** is not among the primary genetic associations for **rheumatoid arthritis**. - Its pathogenic role is more commonly studied in other conditions, such as **coeliac disease**, though various subtypes exist. *HLA DR8* - **HLA-DR8** has some associations with certain autoimmune conditions, such as **primary biliary cholangitis** and **Crohn's disease**. - It is not considered a primary or strong genetic risk factor for **rheumatoid arthritis**.

Question 3: A young girl is admitted with joint pains and butterfly rash and positive urine proteinuria. The best test for her diagnosis is ?

A. Antibodies to RNP
B. Antibodies to tRNA synthetase
C. Anti ds-DNA antibody (Correct Answer)
D. Anti-centromere antibody

Explanation: ***Anti ds-DNA antibody*** - The presence of **joint pains**, a **butterfly rash** (malar rash), and **proteinuria** are classic clinical features highly suggestive of **Systemic Lupus Erythematosus (SLE)** [1]. - **Anti-dsDNA antibodies** are highly specific for SLE and correlate well with disease activity, especially **lupus nephritis**, which is indicated by proteinuria [4]. *Antibodies to RNP* - **Anti-RNP antibodies** are associated with **Mixed Connective Tissue Disease (MCTD)** and can be present in SLE, but they are not as specific for SLE or its renal involvement as anti-dsDNA [2]. - While MCTD can have overlapping features with SLE [3], the combination of a butterfly rash and significant proteinuria steers the diagnosis more directly towards SLE. *Antibodies to tRNA synthetase* - **Anti-tRNA synthetase antibodies** (e.g., anti-Jo-1) are characteristic of **inflammatory myopathies** such as polymyositis and dermatomyositis, not SLE. - These antibodies are typically associated with muscle weakness, interstitial lung disease, and "mechanic's hands," which are not described in the patient's presentation. *Anti-centromere antibody* - **Anti-centromere antibodies** are highly specific for **Limited Cutaneous Systemic Sclerosis (CREST syndrome)** [2]. - CREST syndrome presents with calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias, which are not mentioned in this patient's symptoms.

Question 4: Polyarticular onset JRA involves more than how many joints?

A. 5
B. 3
C. 4 (Correct Answer)
D. 6

Explanation: ***4*** - **Polyarticular onset Juvenile Rheumatoid Arthritis (JRA)**, now often referred to as **Juvenile Idiopathic Arthritis (JIA)**, is defined by the involvement of **five or more joints** within the first six months of the disease. Therefore, "more than 4" correctly describes this threshold. - This subtype of JIA accounts for approximately 30% of all JIA cases and can be further classified into rheumatoid factor-positive and rheumatoid factor-negative forms. *3* - Involvement of **fewer than five joints** (i.e., four or fewer) within the first six months would classify the disease as **oligoarticular JIA**, a distinct and often milder subtype. - Oligoarticular JIA is the most common subtype and often affects large joints like the knees. *5* - While **five or more joints** is the diagnostic criterion for polyarticular JIA, stating "more than 5" would be incorrect as exactly five joints already falls within the polyarticular definition. - The threshold is **equal to or greater than five joints**, not strictly exceeding five. *6* - Specifying "more than 6" joints would exclude cases where 5 or 6 joints are involved, which are still considered polyarticular JIA. - The key diagnostic number is **five**, meaning "more than 4" encompasses the correct definition.

Question 5: An 8-year-old child presents with hematuria 5 days after a throat infection. What is the most likely diagnosis?

A. Post streptococcal nephropathy (Correct Answer)
B. Nephrotic syndrome
C. IgA nephropathy
D. Alport syndrome

Explanation: ***Post streptococcal glomerulonephritis*** - **Post-streptococcal glomerulonephritis (PSGN)** is the most common cause of acute glomerulonephritis in children aged 5-12 years. - Typically presents with **hematuria 1-2 weeks (7-21 days, average 10 days)** after a streptococcal pharyngitis or 3-6 weeks after skin infection. - **5 days post-throat infection** falls within the early range of the latent period for PSGN. - Clinical features include **gross hematuria ("cola-colored" urine)**, **edema**, **hypertension**, and **low C3 complement levels**. - The time interval and clinical presentation in this 8-year-old child are classic for PSGN. *IgA nephropathy* - IgA nephropathy presents with **synpharyngitic hematuria** - occurring **within 1-2 days** (24-48 hours) of an upper respiratory infection. - The **5-day interval** in this case is too long for typical IgA nephropathy presentation. - More common in older children and young adults, and shows normal C3 complement levels. *Nephrotic syndrome* - **Nephrotic syndrome** is characterized by **massive proteinuria (>40 mg/m²/hr)**, **hypoalbuminemia (<2.5 g/dL)**, **edema**, and **hyperlipidemia**. - The primary presentation is **edema and frothy urine**, not acute gross hematuria following infection. - Hematuria, if present, is typically microscopic rather than macroscopic. *Alport syndrome* - **Alport syndrome** is a hereditary nephritis caused by **collagen type IV defects**. - Presents with **persistent microscopic hematuria** from early childhood, often with **sensorineural hearing loss** and **ocular abnormalities**. - Does not have the acute temporal relationship with throat infection seen in this case.

Question 6: A 6-year-old child with abdominal pain and a rash is shown. Comment on the diagnosis?

A. Kawasaki
B. Varicella
C. Meningococcemia
D. Henoch-Schonlein purpura (Correct Answer)

Explanation: ***Henoch Schonlein purpura*** - This diagnosis is strongly suggested by the child's age (6 years old), presentation of abdominal pain, and the characteristic **palpable purpuric rash**, particularly on the lower extremities, as seen in the image. - **Henoch-Schönlein purpura (HSP)**, now known as IgA vasculitis, is a systemic small-vessel vasculitis predominantly affecting children, characterized by the classic triad of palpable purpura, arthritis/arthralgia, and abdominal pain. *Kawasaki* - **Kawasaki disease** primarily affects children under 5 years of age and presents with persistent fever, conjunctivitis, oral mucosal changes (strawberry tongue), cervical lymphadenopathy, and a polymorphous rash. Abdominal pain is less common as a primary feature. - The rash in Kawasaki disease is typically not purpuric but can be maculopapular or scarlatiniform, and does not show the characteristic distribution seen in the image. *Varicella* - **Varicella (chickenpox)** is characterized by a pruritic vesicular rash that progresses from macules to papules to vesicles and then crusts, usually starting on the trunk and spreading centrifugally. This is distinctly different from the purpuric rash shown. - While it can cause abdominal pain, the skin lesions are the key differentiator, and the image does not depict vesicular lesions. *Meningococcemia* - **Meningococcemia** is a severe bacterial infection often presenting with petechial or purpuric rash, fever, and signs of sepsis. However, the rash in meningococcemia rapidly progresses to large ecchymoses and is often associated with signs of critical illness (e.g., hypotension, altered mental status). - While purpura is present, the widespread, relatively uniform appearance of the rash, combined with abdominal pain in a 6-year-old, points away from the fulminant course typical of meningococcemia towards a vasculitis like HSP.

Question 7: A 1-year-old unimmunised child with HbsAg positivity is having following skin lesions. What is the diagnosis?

A. Gianotti-Crosti syndrome (Correct Answer)
B. Erythema infectiosum
C. Pityriasis alba
D. Pityriasis rosea

Explanation: ***Gianotti-Crosti syndrome*** - This syndrome is characterized by a **papular acrodermatitis** of childhood, typically presenting as monomorphic, erythematous papules on the face, buttocks, and extensor surfaces of the extremities. - It is strongly associated with **viral infections**, particularly **Hepatitis B virus (HBV)** and Epstein-Barr virus (EBV), which aligns with the HbsAg positivity in this unimmunized child. *Erythema infectiosum* - This condition is caused by **Parvovirus B19** and typically presents with a "slapped cheek" rash on the face, followed by a lacy, reticulated rash on the trunk and extremities. - The rash in the image does not demonstrate the characteristic lacy pattern or typical "slapped cheek" appearance. *Pityriasis alba* - This is a common, mild, and often asymptomatic skin condition characterized by **hypopigmented (lighter) patches** with fine scales, predominantly on the face and arms. - The lesions in the image are erythematous (red) and papular, not hypopigmented. *Pityriasis rosea* - This condition typically begins with a single, larger "herald patch" followed by smaller, oval-shaped, pinkish-red patches with a characteristic **"Christmas tree" pattern** on the trunk and proximal extremities. - The rash in the image does not show a herald patch or the distinct distribution and morphology of pityriasis rosea.

Question 8: Which of the following statements are correct regarding the management of gastrointestinal bleeding in children? I. Somatostatin or octreotide infusion should be given for at least 7 days after stoppage of initial bleeding to prevent rebleeding II. Endoscopic Sclerotherapy (EST) involves endoscopic injection of N -butyl-2-cyanoacrylate or iso-butyl-2-cyanoacrylate III. EST has upto 90 % efficacy in controlling acute bleeding IV. Following an episode of acute variceal bleeding, all patients should receive secondary prophylaxis to prevent rebleeding Select the answer using the code given below :

A. III and IV (Correct Answer)
B. I and III
C. II and IV
D. I and II

Explanation: ***III and IV*** **Statement I is INCORRECT:** Somatostatin or octreotide infusions are typically administered for **3-5 days** (not 7 days) after initial bleeding has stopped to prevent rebleeding. Prolonged use beyond this period is not generally recommended due to potential side effects and lack of additional benefit. **Statement II is INCORRECT:** Endoscopic Sclerotherapy (EST) for esophageal varices involves injection of sclerosants such as **ethanolamine oleate, sodium tetradecyl sulfate**, or polidocanol. The tissue adhesives **N-butyl-2-cyanoacrylate** or **iso-butyl-2-cyanoacrylate** are used in **endoscopic variceal obturation (EVO)** for **gastric varices**, not in standard sclerotherapy for esophageal varices. **Statement III is CORRECT:** Endoscopic Sclerotherapy (EST) demonstrates **up to 90% efficacy** in controlling acute variceal bleeding, making it a highly effective intervention for managing acute hemorrhage. **Statement IV is CORRECT:** Following an episode of acute variceal bleeding, **all patients should receive secondary prophylaxis** (typically combination of non-selective beta-blockers and endoscopic band ligation) to prevent rebleeding, which is associated with significant morbidity and mortality. *I and III* - Incorrect because Statement I is wrong about the duration of vasoactive drug therapy. *II and IV* - Incorrect because Statement II confuses sclerotherapy agents with tissue adhesives used for gastric varices. *I and II* - Incorrect because both statements I and II contain inaccuracies regarding duration of therapy and sclerosing agents respectively.

Question 9: What is a characteristic feature of Systemic Juvenile Idiopathic Arthritis?

A. Uveitis is a feature
B. It occurs after 16 years of age
C. NSAIDs are contraindicated
D. RA factor is negative (Correct Answer)

Explanation: ### Explanation **Systemic Juvenile Idiopathic Arthritis (sJIA)**, also known as Still’s disease, is a unique subtype of JIA characterized by prominent extra-articular features. **Why the correct answer is right:** In sJIA, the **Rheumatoid Factor (RF) is characteristically negative**. Unlike the polyarticular subtype (which can be RF positive), sJIA is considered an autoinflammatory disease rather than a classic autoimmune disease. Diagnosis is clinical, based on the presence of arthritis in one or more joints associated with (or preceded by) a fever of at least 2 weeks' duration that is daily ("quotidian") for at least 3 days, accompanied by features like an evanescent salmon-pink rash, lymphadenopathy, or serositis. **Analysis of Incorrect Options:** * **A. Uveitis is a feature:** This is incorrect for sJIA. Chronic anterior uveitis is a classic complication of **Oligoarticular JIA** (especially if ANA positive). Uveitis is very rare in the systemic subtype. * **B. It occurs after 16 years of age:** By definition, JIA must have an onset **before the age of 16**. If similar symptoms occur after 16, it is termed Adult-Onset Still’s Disease (AOSD). * **C. NSAIDs are contraindicated:** This is false. NSAIDs are often the **first-line** symptomatic treatment for pain and fever in JIA, though systemic steroids or biologics (IL-1 and IL-6 inhibitors) are usually required for definitive control. **High-Yield Clinical Pearls for NEET-PG:** * **Fever Pattern:** Classic "Quotidian" fever (spikes once daily, usually in the evening, returning to baseline). * **Laboratory Markers:** Marked leukocytosis, thrombocytosis, and highly elevated ESR/CRP. * **Ferritin:** Extremely high ferritin levels are common and can signal the onset of **Macrophage Activation Syndrome (MAS)**, a life-threatening complication of sJIA. * **Biologics of Choice:** Tocilizumab (IL-6 inhibitor) and Anakinra/Canakinumab (IL-1 inhibitors).

Question 10: A child presents with delayed separation of the umbilical cord, leukocytosis, Down syndrome, and recurrent infections. What is the most likely diagnosis?

A. Leukocyte Adhesion Deficiency (Correct Answer)
B. Neonatal Sepsis
C. Histiocytosis-X
D. All of the above

Explanation: ### Explanation **Correct Option: A. Leukocyte Adhesion Deficiency (LAD)** **Why it is correct:** Leukocyte Adhesion Deficiency (Type 1) is a primary immunodeficiency caused by a defect in the **CD18 subunit of $\beta_2$-integrins**. This defect prevents neutrophils from adhering to the vascular endothelium and migrating into tissues (diapedesis). * **Delayed separation of the umbilical cord:** This is the classic hallmark of LAD. Normally, neutrophils infiltrate the cord stump to facilitate its detachment; in LAD, the absence of neutrophils at the site leads to delayed separation (often >30 days). * **Leukocytosis:** Because neutrophils cannot leave the bloodstream to enter tissues, they accumulate in the blood, leading to persistent, marked neutrophilic leukocytosis. * **Recurrent Infections:** Patients suffer from skin and mucosal infections (e.g., omphalitis, periodontitis) characterized by a **lack of pus formation** despite high white cell counts. * **Association:** While not a primary feature, LAD has been documented in case reports involving children with Down syndrome. **Why other options are incorrect:** * **B. Neonatal Sepsis:** While sepsis causes leukocytosis and infections, it does not explain the specific anatomical delay in umbilical cord separation. * **C. Histiocytosis-X (Langerhans Cell Histiocytosis):** This typically presents with seborrheic-like skin rashes, lytic bone lesions, and hepatosplenomegaly, rather than a specific defect in cord separation or integrin function. **High-Yield Clinical Pearls for NEET-PG:** * **LAD Type 1:** Defect in **CD18** (Integrins). * **LAD Type 2:** Defect in **Sialyl-Lewis X** (Selectins); presents with short stature and intellectual disability. * **Key Triad:** Delayed cord separation + Recurrent "cold" infections (no pus) + Extreme neutrophilia. * **Diagnosis:** Confirmed by **Flow Cytometry** showing decreased expression of CD11/CD18.

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