Infectious Systemic Diseases — MCQs
A child presents with a fever and a rash. Urine examination showed cells with owl's eye appearance. What is the most likely diagnosis?
What is the most common eye lesion in HIV?
In secondary syphilis all are seen except -
A malnourished child from a poor socioeconomic status, residing in overcrowded and dirty areas, presents with a nodule around the limbus and hyperemia of the surrounding conjunctiva in his left eye, as well as axillary and cervical lymphadenopathy. Which of the following is the most likely diagnosis?
Interstitial keratitis is associated with all of the following except:
The most characteristic manifestation of congenital toxoplasmosis is:
One year old male child with cat's reflex and raised IOP. What is the most likely diagnosis?
A 60-year-old female with a history of diabetes presents with nasal congestion, facial pain, and black necrotic patches on the palate. What is the most likely diagnosis?
Retinitis pigmentosa is a feature of all except which of the following?
Pelvic abscess can present with all symptoms except:
Infectious Systemic Diseases Indian Medical PG Practice Questions and MCQs
Question 1: A child presents with a fever and a rash. Urine examination showed cells with owl's eye appearance. What is the most likely diagnosis?
- A. Herpes simplex virus infection
- B. Toxoplasmosis caused by Toxoplasma gondii
- C. Cytomegalovirus (CMV) infection (Correct Answer)
- D. Infectious mononucleosis caused by Epstein-Barr virus
Explanation: ***Cytomegalovirus (CMV) infection*** - The presence of cells with an **owl's eye appearance** in urine sediment is a classic histological hallmark of **CMV infection**. - CMV can cause a variety of symptoms in children, including **fever and rash**, making this the most likely diagnosis. *Herpes simplex virus infection* - HSV causes characteristic **vesicular lesions** on mucocutaneous surfaces, often associated with fever. - While HSV can cause systemic illness, it does not typically present with **owl's eye inclusions** in urine cells. *Toxoplasmosis caused by Toxoplasma gondii* - **Toxoplasmosis** can cause fever and rash, especially in congenital infections or immunocompromised individuals. - However, it does not lead to **owl's eye inclusions** in urinary cells, which are pathognomonic for CMV. *Infectious mononucleosis caused by Epstein-Barr virus* - **Infectious mononucleosis** commonly presents with fever, fatigue, and lymphadenopathy, sometimes with a rash. - **Epstein-Barr virus (EBV)** infection does not produce cells with an **owl's eye appearance** in the urine; that is specific to CMV.
Question 2: What is the most common eye lesion in HIV?
- A. Kaposi Sarcoma of Lid
- B. Cotton wool spots (Correct Answer)
- C. CMV Retinitis
- D. Choroiditis
Explanation: ***Cotton wool spots*** - These are the most common ocular manifestation in HIV-positive individuals, resulting from **ischemic retinal nerve fiber layer damage**. - While not vision-threatening themselves, their presence indicates **microvascular damage** and can be a sign of systemic disease progression. *Kaposi Sarcoma of Lid* - While Kaposi sarcoma can affect the eyelids in HIV patients, it is **not the most common ocular lesion**. - It presents as a **reddish-purple nodule** or plaque and is an indicator of advanced immunosuppression. *CMV Retinitis* - Cytomegalovirus (CMV) retinitis is a significant and **vision-threatening opportunistic infection** in advanced HIV. - However, it occurs in patients with **severe immunosuppression** (low CD4 counts) and is less common overall than cotton wool spots. *Choroiditis* - Choroiditis, an inflammation of the choroid, can occur in HIV patients due to various opportunistic infections or directly from the virus. - It is **less prevalent** than cotton wool spots and typically requires specific etiologies beyond HIV itself.
Question 3: In secondary syphilis all are seen except -
- A. Interstitial keratitis (Correct Answer)
- B. Arthritis
- C. Proteinuria
- D. Condyloma lata
Explanation: ***Interstitial keratitis*** - **Interstitial keratitis** is a hallmark manifestation of **congenital syphilis**, not secondary syphilis. - It involves non-ulcerative inflammation of the cornea, leading to scarring and vision loss. *Arthritis* - **Arthritis** can occur in secondary syphilis, typically presenting as a **non-inflammatory polyarthritis** affecting large joints. - This is due to the systemic effects of widespread spirochete dissemination. *Proteinuria* - **Proteinuria** can be a feature of **syphilitic glomerulonephritis**, which can occur during the secondary stage. - This renal involvement is a less common but recognized complication. *Condyloma lata* - **Condyloma lata** are highly infectious, raised, grayish-white lesions found in moist areas, such as the anogenital region and oral mucosa [1]. - They are a classic and highly characteristic skin manifestation of **secondary syphilis** [1].
Question 4: A malnourished child from a poor socioeconomic status, residing in overcrowded and dirty areas, presents with a nodule around the limbus and hyperemia of the surrounding conjunctiva in his left eye, as well as axillary and cervical lymphadenopathy. Which of the following is the most likely diagnosis?
- A. Phlyctenular conjunctivitis (Correct Answer)
- B. Foreign body granuloma
- C. Vernal keratoconjunctivitis
- D. Episcleritis
Explanation: ***Phlyctenular conjunctivitis*** - This condition is an immune-mediated hypersensitivity reaction to a foreign antigen, often associated with systemic diseases like **tuberculosis** or **Staphylococcus aureus** infection, commonly seen in malnourished children from poor socioeconomic backgrounds. - The characteristic lesion is a **nodule (phlyctenule)** near the **limbus** with surrounding conjunctival hyperemia, which aligns with the child's presentation. *Foreign body granuloma* - A **foreign body granuloma** is a reaction to a foreign material embedded in the conjunctiva or sclera, typically caused by trauma or an identifiable foreign object. - It does not explain the concurrent **axillary and cervical lymphadenopathy** or the association with malnutrition and poor hygiene. *Vernal keratoconjunctivitis* - **Vernal keratoconjunctivitis** is a chronic, bilateral allergic disorder, primarily affecting children and young adults, often seasonal and related to atopy. - It is characterized by **giant papillae on the tarsal conjunctiva** and often forms a **Trantas dot** on the limbus, which are different from a single limbal nodule and not typically associated with lymphadenopathy or socioeconomic factors in this way. *Episcleritis* - **Episcleritis** is an acute, self-limiting inflammation of the episcleral tissue, presenting as **sectoral or diffuse redness** and mild discomfort. - It does not involve a distinct nodule around the limbus or systemic symptoms like **lymphadenopathy**, nor is it directly linked to malnutrition or poor hygiene.
Question 5: Interstitial keratitis is associated with all of the following except:
- A. Syphilis
- B. Acanthamoeba (Correct Answer)
- C. Chlamydia Trachomatis
- D. Herpes Zoster Virus (HZV)
Explanation: ***Acanthamoeba*** - **Acanthamoeba keratitis** is a **suppurative keratitis** characterized by a painful, ring-shaped infiltrate with epithelial ulceration, typically associated with contact lens use and contaminated water exposure. - It causes **ulcerative stromal inflammation**, not the **non-ulcerative deep stromal inflammation** that characterizes classic interstitial keratitis. - **This is NOT a cause of interstitial keratitis.** *Syphilis* - **Congenital syphilis** is the **CLASSIC cause** of bilateral **interstitial keratitis**, often presenting in late childhood with "salmon patch" appearance, photophobia, lacrimation, and eventual ghost vessels. - The inflammation is **non-ulcerative and chronic**, affecting the **deep corneal stroma** with preservation of epithelium. - This is the most important association with interstitial keratitis to remember. *Chlamydia Trachomatis* - **Chlamydia trachomatis** causes **trachoma**, a chronic keratoconjunctivitis leading to **superficial keratitis with pannus formation** (superficial vascularization from the limbus). - The corneal involvement in trachoma is **superficial**, not the deep stromal inflammation seen in classic interstitial keratitis. - While listed in some references, **Chlamydia is NOT a standard cause of interstitial keratitis** in major ophthalmology textbooks. - **Note:** This option is potentially debatable, but Acanthamoeba is the more definitively incorrect answer. *Herpes Zoster Virus (HZV)* - **Herpes zoster ophthalmicus** can lead to **interstitial keratitis** and **disciform keratitis** (immune-mediated stromal inflammation with disc-shaped corneal edema). - Similarly, **HSV (Herpes Simplex Virus)** causes stromal keratitis, a form of interstitial keratitis. - The corneal involvement includes **deep stromal inflammation, scarring**, and potential neurotrophic changes leading to vision impairment.
Question 6: The most characteristic manifestation of congenital toxoplasmosis is:
- A. Intracranial calcifications (Correct Answer)
- B. Deafness
- C. Thrombocytopenia
- D. Hepatosplenomegaly
Explanation: ***Intracranial calcifications*** - **Intracranial calcifications**, particularly scattered and diffuse throughout the brain parenchyma, are the most **characteristic and pathognomonic** finding of congenital toxoplasmosis - These calcifications result from the parasite's predilection for **neural tissue** and subsequent inflammatory necrosis - Along with **hydrocephalus** and **chorioretinitis**, they form the **classic triad** of congenital toxoplasmosis - The scattered pattern of calcifications helps differentiate toxoplasmosis from CMV (which causes periventricular calcifications) *Deafness* - **Sensorineural hearing loss** can occur but is not a characteristic feature of congenital toxoplasmosis - Deafness is more commonly associated with congenital **cytomegalovirus (CMV)** or **rubella** infection - When present in toxoplasmosis, it is typically a late sequela rather than a primary manifestation *Thrombocytopenia* - **Thrombocytopenia** may occur as part of generalized systemic involvement but is a **non-specific finding** - It can be seen in many congenital infections (TORCH complex) - Not diagnostically useful for distinguishing toxoplasmosis from other congenital infections *Hepatosplenomegaly* - **Hepatosplenomegaly** indicates systemic infection and may reflect **extramedullary hematopoiesis** - Common in many congenital infections, making it non-specific - The most **diagnostically valuable** findings in congenital toxoplasmosis are the neurological (intracranial calcifications, hydrocephalus) and ocular (chorioretinitis) manifestations
Question 7: One year old male child with cat's reflex and raised IOP. What is the most likely diagnosis?
- A. Toxocara canis
- B. Retinopathy of prematurity
- C. Retinoblastoma (Correct Answer)
- D. Toxoplasma gondii infection
Explanation: ***Retinoblastoma*** - A **cat's reflex (leukocoria)**, which is a white pupillary reflex, is the most common presenting sign of retinoblastoma in children. - **Raised intraocular pressure (IOP)** can occur in advanced retinoblastoma due to secondary glaucoma caused by tumor growth or neovascularization. *Toxocara canis* - Ocular **toxocariasis** can cause leukocoria and inflammation, but it's typically associated with **granuloma formation** and not usually primary elevated IOP. - This condition is caused by a **parasitic infection** from roundworms, often seen in children with exposure to contaminated soil or pets. *Retinopathy of prematurity* - Primarily affects **premature infants** exposed to high oxygen, leading to abnormal retinal vessel development. - While it can cause leukocoria in severe stages, it would be unusual for a **one-year-old** to present with this primary diagnosis especially with raised IOP. *Toxoplasma gondii infection* - Ocular **toxoplasmosis** typically presents with **chorioretinitis** and can cause inflammation, but **leukocoria** and **raised IOP** are not its primary or most characteristic features. - This is a parasitic infection, congenital or acquired, often presenting with **retinal scars**.
Question 8: A 60-year-old female with a history of diabetes presents with nasal congestion, facial pain, and black necrotic patches on the palate. What is the most likely diagnosis?
- A. Bacterial sinusitis
- B. Mucormycosis (Correct Answer)
- C. Rhinoscleroma
- D. Granulomatosis with Polyangiitis (GPA)
Explanation: ***Mucormycosis*** - The presence of **black necrotic patches on the palate** in a diabetic patient with sinusitis symptoms is highly characteristic of mucormycosis. - **Diabetes** is a significant risk factor for this aggressive fungal infection, which often presents with tissue necrosis. *Bacterial sinusitis* - While facial pain and nasal congestion are consistent with bacterial sinusitis, **black necrotic patches** are not a typical feature. - Bacterial sinusitis rarely causes deep tissue invasion and necrosis of this extent. *Rhinoscleroma* - This is a chronic granulomatous disease of the upper respiratory tract caused by *Klebsiella rhinoscleromatis*, primarily seen in specific endemic regions. - It presents with **progressive inflammatory masses** and **scarring**, not acute necrosis or black patches. *Granulomatosis with Polyangiitis (GPA)* - GPA can cause sinusitis, **nasal crusting**, and **cartilage destruction**, but typically presents with **granulomatous inflammation** and vasculitis, not primary necrotic patches on the palate. - It is often associated with **ANCA positivity** and systemic symptoms affecting the lungs and kidneys.
Question 9: Retinitis pigmentosa is a feature of all except which of the following?
- A. NARP
- B. Refsum's disease
- C. Hallervorden-Spatz disease (Correct Answer)
- D. Abetalipoproteinemia
Explanation: ***Hallervorden-Spatz disease*** - Also known as **Pantothenate kinase-associated neurodegeneration (PKAN)**, this disorder primarily causes **extrapyramidal symptoms** such as dystonia and parkinsonism due to iron accumulation in the basal ganglia. - While it is a neurodegenerative disorder affecting the brain, **retinitis pigmentosa** is not a characteristic feature of Hallervorden-Spatz disease. *Refsum's disease* - This is an **autosomal recessive peroxisomal disorder** characterized by the accumulation of **phytanic acid**, which is toxic to various tissues. - **Retinitis pigmentosa** is a classic symptom, often presenting with night blindness and progressive vision loss, along with **ataxia**, **polyneuropathy**, and **ichthyosis**. *NARP* - **NARP (Neuropathy, Ataxia, Retinitis Pigmentosa)** is a rare mitochondrial disorder caused by mutations in the **MT-ATP6 gene**, leading to energy production deficits. - **Retinitis pigmentosa** is a core feature, contributing to visual impairment, alongside **sensory neuropathy**, **ataxia**, and **developmental delay**. *Abetalipoproteinemia* - This is an **autosomal recessive disorder** characterized by the inability to synthesize **apolipoprotein B**, essential for the formation of chylomicrons and VLDL, leading to severe **malabsorption of fat-soluble vitamins** (A, D, E, K). - Prolonged deficiency of **vitamin E** can result in progressive neurological dysfunction, including **ataxia** and **retinitis pigmentosa**, due to oxidative damage to photoreceptors and nervous tissue.
Question 10: Pelvic abscess can present with all symptoms except:
- A. bleeding rectum (Correct Answer)
- B. pain abdomen
- C. diarrhea with mucus discharge
- D. fever
Explanation: ***bleeding rectum*** - A **bleeding rectum** is not a typical presentation of a pelvic abscess. It might suggest other conditions like hemorrhoids, colorectal cancer, or inflammatory bowel disease. - Pelvic abscesses are collections of pus in the pelvic cavity, and while they can cause various gastrointestinal symptoms due to local inflammation and pressure, direct rectal bleeding is generally not among them. *pain abdomen* - **Abdominal pain** is a very common symptom of a pelvic abscess, often localized to the lower abdomen. - This pain is caused by inflammation, pressure, and irritation of surrounding organs and tissues. *diarrhea with mucus discharge* - A pelvic abscess can cause irritation to the adjacent **bowel segments**, leading to changes in bowel habits such as diarrhea. - The presence of **mucus discharge** can also be a sign of bowel irritation or inflammation, which can occur secondary to a nearby abscess. *fever* - **Fever** is a classic systemic sign of infection and inflammation, and thus is almost always present in patients with an abscess, including a pelvic abscess. - The body's inflammatory response to the infection typically elevates body temperature.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free