Infectious Diseases Practice Questions

Q: The following cell type is seen in peripheral smear of a patient with membrane over the tonsils. All can be used in treatment except?

Acyclovir. ***Acyclovir*** - The image depicts an **atypical lymphocyte** (Downey cell), characteristic of **infectious mononucleosis**, commonly caused by the **Epstein-Barr virus (EBV)**. - Acyclovir is an **antiviral medication** primarily used for **herpes simplex virus (HSV)** and **varicella-zoster virus (VZV)** infections, and it is **not effective against EBV**. *Prednisolone* - **Corticosteroids** like prednisolone may be used in severe cases of infectious mononucleosis, especially when complications such as **airway obstruction** due to tonsillar hypertrophy, **hemolytic anemia**, or **thrombocytopenia** are present. - They help to **reduce inflammation** and suppress the immune response. *IVIG* - **Intravenous immunoglobulin (IVIG)** can be used in rare, severe, or complicated cases of infectious mononucleosis, particularly if there are significant **hematologic complications** (e.g., severe thrombocytopenia, severe hemolytic anemia) or in patients with **immunodeficiency**. - IVIG provides **passive immunity** and modulates the immune response. *Acetaminophen* - **Acetaminophen (paracetamol)** is a common **analgesic** and **antipyretic** used to manage symptomatic relief for fever, sore throat, and muscle aches associated with infectious mononucleosis. - It helps to **alleviate discomfort** and improve patient well-being during the acute phase of the illness.

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

Gianotti-Crosti syndrome. ***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.

Q: A child presents with low grade fever for 5 days, joint pain in large joints and palpable purpuric rash on lower extremities and buttocks. The most probable diagnosis is:

Henoch-Schönlein purpura. ***Henoch-Schönlein purpura*** - This diagnosis is characterized by the classic triad of **palpable purpura**, especially on the lower extremities and buttocks, **arthralgia** (joint pain), and **abdominal pain**, often preceded by an upper respiratory infection with a low-grade fever. - The disease involves **IgA deposition** in small blood vessels, leading to vasculitis, which explains the purpuric rash. *Rheumatic fever* - While it can cause fever and large joint polyarthritis (migratory in nature), it is typically associated with a history of **streptococcal pharyngitis** and can involve the heart (carditis) and central nervous system (Sydenham chorea), which are not mentioned. - The characteristic rash is **erythema marginatum**, not palpable purpura. *Acute ITP* - **Immune thrombocytopenic purpura (ITP)** involves a low platelet count, leading to purpura and petechiae, but these are typically non-palpable. - ITP does not characteristically cause joint pain or systemic signs of vasculitis like Henoch-Schönlein purpura. *Purpura fulminans* - This is a severe, acute, and often rapidly progressive condition characterized by large, confluent areas of **purpura with necrosis** and gangrene, often associated with sepsis or severe infection, and disseminated intravascular coagulation (DIC). - The presentation in the question describes a less severe, more localized, and palpable purpuric rash with joint pain, not widespread necrosis.

Q: A 12-year-old child presents with fever, sore throat for 3 days and posterior cervical lymphadenopathy. Peripheral smear was performed. Diagnosis is?

Infectious mononucleosis. ***Infectious mononucleosis*** - The image shows an **atypical lymphocyte** (Downey cell), characterized by a large, irregularly shaped nucleus and abundant, basophilic cytoplasm, often indenting surrounding red blood cells. These are characteristic of infectious mononucleosis. - The clinical presentation of **fever**, **sore throat**, and **posterior cervical lymphadenopathy** in a 12-year-old child is typical for infectious mononucleosis, commonly caused by the **Epstein-Barr virus (EBV)**. *Hodgkin lymphoma* - While Hodgkin lymphoma presents with lymphadenopathy, it typically involves **Reed-Sternberg cells** on biopsy, which are not seen in a peripheral smear. - Furthermore, the clinical course and presentation of Hodgkin lymphoma are usually more chronic and would not typically present with the acute viral-like syndrome described. *CLL* - **Chronic Lymphocytic Leukemia (CLL)** is a malignancy of mature B lymphocytes, primarily affecting older adults, and would be rare in a 12-year-old. - Peripheral smears in CLL show mature-appearing lymphocytes, often with "smudge cells," which are distinct from the atypical lymphocytes seen in the image. *Herpangina* - Herpangina is a viral illness causing **fever** and **painful mouth sores** (vesicles and ulcers) in the posterior oropharynx, often caused by Coxsackievirus. - While it can cause fever and sore throat, it does not typically present with significant lymphadenopathy, especially **posterior cervical lymphadenopathy**, and would not show atypical lymphocytes on a peripheral smear.

Q: Which of the following statements are correct regarding vaccination routes for children? I. Hepatitis B vaccine given in deltoid region has reduced efficacy II. Two vaccines may be given in the same thigh, but separated by 1 inch III. Separate sites are used when administering a vaccine and an immunoglobulin IV. Two intramuscular vaccines should never be given on the same day Select the answer using the code given below:

II and III. ***II and III*** - Hepatitis B vaccine can be given in the **deltoid region** for older children and adults with good efficacy; reduced efficacy primarily occurs if administered in the gluteal region due to high fat content, not the deltoid. Administering two vaccines in the same thigh, separated by 1 inch, is a recognized practice when multiple injections are needed and separate limbs are not feasible. - Administering a vaccine and an immunoglobulin at **separate sites** is crucial to prevent the immunoglobulin from neutralizing the live attenuated vaccine, thereby reducing its efficacy. *I and III* - Statement I is incorrect because the **deltoid region** is an appropriate and effective site for Hepatitis B vaccine administration in older children and adults. - Statement III is correct, as separating the sites for vaccine and immunoglobulin prevents **immune interference**. *III only* - While statement III is correct regarding the separation of vaccine and immunoglobulin administration, statement II is also correct, making this option incomplete. - **Multiple injections** on the same limb with adequate spacing are acceptable under certain guidelines. *II, III, and IV* - Statement IV is incorrect; multiple **intramuscular vaccines** *can* be given on the same day if clinically indicated and the child is due for them, often in different limbs or at appropriately spaced sites on the same limb. - Statements II and III are correct, but the inclusion of the incorrect statement IV makes this option invalid.

Q: All cases of severe measles and all cases of measles in areas with high case fatality rate need to be treated with which of the following vitamins?

Vitamin A. ***Vitamin A*** - **Vitamin A supplementation** is recommended for severe measles cases, especially in areas with high case fatality rates. - It helps to reduce morbidity and mortality by improving immune function and supporting the integrity of epithelial tissues. *Vitamin K* - **Vitamin K** is primarily involved in **blood clotting** and bone metabolism. - There is no established role for Vitamin K supplementation in the treatment or prognosis of measles. *Vitamin C* - **Vitamin C** is an **antioxidant** and supports immune function, but its role in measles management is not supported by strong evidence or recommendations. - While beneficial for overall immunity, it is not specifically indicated for severe measles as a life-saving intervention. *Vitamin D* - **Vitamin D** plays a crucial role in **bone health** and modulating the immune system. - Like Vitamin C, it has general immune benefits but is not a specific or recommended treatment for severe measles or its complications.

Q: In measles, when do the Koplik's spots appear?

1-2 days before the rashes appear. ***1-2 days before the rashes appear*** - **Koplik's spots** are considered an **enanthem**, a pathognomonic sign of **measles**. - These small, white spots with a bluish-white center on an erythematous base on the buccal mucosa typically appear 1-2 days before the generalized maculopapular rash. *On the day that rashes appear* - The generalized **maculopapular rash** of measles typically appears a few days *after* Koplik's spots. - While the rash is a hallmark of measles, it is preceded by the oral lesions. *On the day that fever occurs* - **Fever** is usually one of the initial symptoms of measles, often appearing several days before Koplik's spots. - The fever is part of the **prodromal phase**, which includes cough, coryza, and conjunctivitis. *1-2 days before the fever occurs* - Measles symptoms, including fever, are usually the first indicators of infection, making it unlikely for a specific sign like Koplik's spots to appear before the fever itself. - The incubation period precedes any symptoms, including fever.

Q: Varicella-Zoster Immunoglobulin (VZIG) is NOT recommended for which of the exposed susceptible individuals?

Healthy sibling. ***Correct: Healthy sibling*** - VZIG is administered to **susceptible individuals** upon exposure to **Varicella-Zoster Virus (VZV)** to prevent or attenuate the infection - A **healthy sibling** with a **competent immune system** would typically mount an adequate immune response to the virus - VZIG is therefore **NOT indicated** for immunocompetent individuals as they can handle the infection naturally - VZIG is reserved for **high-risk populations** where varicella could cause severe complications *Incorrect: HIV/AIDS positive* - Individuals with **HIV/AIDS** are considered **immunocompromised** and are at **higher risk** for severe varicella infection and complications - VZIG **IS recommended** for these patients after exposure to VZV to provide **passive immunity** and reduce disease severity - This is particularly important in patients with CD4 counts <200 cells/μL *Incorrect: Newborn* - **Newborns** whose mothers developed varicella **5 days before to 2 days after delivery** are at high risk for severe, disseminated neonatal varicella - **VZIG IS recommended** for these neonates to offer immediate protection against the virus - Also indicated for premature infants <28 weeks or <1000g who are exposed, regardless of maternal immunity *Incorrect: Pregnant women* - **Pregnant women** who are **non-immune to varicella** and exposed to VZV are at risk for both **maternal complications** (varicella pneumonia) and **fetal abnormalities** (congenital varicella syndrome) - **VZIG IS recommended** for susceptible pregnant women exposed to varicella to reduce the risk of severe maternal disease - Should be administered within **10 days** of exposure, preferably within 96 hours

Q: The classical triad of congenital defects in Congenital Rubella Syndrome include which of the following? 1. Hydrocephalus 2. Deafness 3. Cardiac malformations 4. Cataract

2, 3 and 4. ***2, 3 and 4*** - The classical triad of congenital defects associated with **Congenital Rubella Syndrome (CRS)** typically refers to **deafness**, **cataracts**, and **cardiac malformations**. - These are the most common and prominent features that result from transplacental infection during early pregnancy. *1, 2 and 3 and 4* - This option incorrectly includes **hydrocephalus** as part of the classical triad. While other neurological manifestations can occur in CRS, hydrocephalus is not a defining feature of the classical triad. - The three most prominent and characteristic defects in CRS are **deafness, cataracts, and cardiac malformations**. *1, 2 and 4* - This option incorrectly includes **hydrocephalus** and omits **cardiac malformations**, which is a key component of the classical triad. - The classical triad specifically highlights defects in the **eyes (cataracts)**, **ears (deafness)**, and **heart (cardiac malformations)**. *1, 2 and 3* - This option incorrectly includes **hydrocephalus** and omits **cataracts**, which is a definitive feature of the classical triad of CRS. - While cardiac and auditory defects (deafness) are part of the triad, ocular defects (cataracts) are equally crucial for the classical definition.

Q: Hepatitis B vaccine administered at birth is

A monovalent vaccine of Hepatitis B. ***A monovalent vaccine of Hepatitis B*** - The **initial dose** of the Hepatitis B vaccine given at birth is a **single-antigen (monovalent)** preparation. It is given as a **standalone vaccine** to ensure prompt protection against Hepatitis B virus. - This early administration is critical for preventing **perinatal transmission** of Hepatitis B from an infected mother to her newborn, and establishing immunity as soon as possible. *A pentavalent vaccine* - **Pentavalent vaccines** typically protect against five different diseases: **Diphtheria, Tetanus, Pertussis (DTP), *Haemophilus influenzae* type b (Hib), and Hepatitis B**. - While Hepatitis B is one component, the vaccine administered at birth is usually monovalent, and the pentavalent vaccine is given later in the infant's immunization schedule. *A fixed combination vaccine of Hepatitis B and Hib* - A fixed combination vaccine of Hepatitis B and **Hib (Haemophilus influenzae type b)** is available and used in some immunization schedules. - However, the **first dose** given at birth is specifically a monovalent Hepatitis B vaccine, not a combined Hib vaccine, to target immediate Hepatitis B protection. *A combined vaccine of inactivated Polio and Hepatitis B* - Combined vaccines that include **inactivated Polio vaccine (IPV)** and **Hepatitis B** do exist but are generally administered later, at 6 weeks and subsequent doses. - The **birth dose** of Hepatitis B vaccine is exclusively for Hepatitis B protection and does not typically include polio antigen.

Question 1

The following cell type is seen in peripheral smear of a patient with membrane over the tonsils. All can be used in treatment except?

Accepted Answer

Acyclovir

Answer

Prednisolone

Answer

IVIG

Answer

Acetaminophen

Question 2

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

Accepted Answer

Gianotti-Crosti syndrome

Answer

Erythema infectiosum

Answer

Pityriasis alba

Answer

Pityriasis rosea

Question 3

A child presents with low grade fever for 5 days, joint pain in large joints and palpable purpuric rash on lower extremities and buttocks. The most probable diagnosis is:

Accepted Answer

Henoch-Schönlein purpura

Answer

Rheumatic fever

Answer

Acute ITP

Answer

Purpura fulminans

Question 4

A 12-year-old child presents with fever, sore throat for 3 days and posterior cervical lymphadenopathy. Peripheral smear was performed. Diagnosis is?

Accepted Answer

Infectious mononucleosis

Answer

Hodgkin lymphoma

Answer

CLL

Answer

Herpangina

Question 5

Which of the following statements are correct regarding vaccination routes for children?
I. Hepatitis B vaccine given in deltoid region has reduced efficacy
II. Two vaccines may be given in the same thigh, but separated by 1 inch
III. Separate sites are used when administering a vaccine and an immunoglobulin
IV. Two intramuscular vaccines should never be given on the same day

Select the answer using the code given below:

Accepted Answer

II and III

Answer

I and III

Answer

III only

Answer

II, III, and IV

Question 6

All cases of severe measles and all cases of measles in areas with high case fatality rate need to be treated with which of the following vitamins?

Accepted Answer

Vitamin A

Answer

Vitamin K

Answer

Vitamin C

Answer

Vitamin D

Question 7

In measles, when do the Koplik's spots appear?

Accepted Answer

1-2 days before the rashes appear

Answer

On the day that rashes appear

Answer

On the day that fever occurs

Answer

1-2 days before the fever occurs

Question 8

Varicella-Zoster Immunoglobulin (VZIG) is NOT recommended for which of the exposed susceptible individuals?

Accepted Answer

Healthy sibling

Answer

HIV/AIDS positive

Answer

Newborn

Answer

Pregnant women

Question 9

The classical triad of congenital defects in Congenital Rubella Syndrome include which of the following?

1. Hydrocephalus
2. Deafness
3. Cardiac malformations
4. Cataract

Accepted Answer

2, 3 and 4

Answer

1, 2 and 3 and 4

Answer

1, 2 and 4

Answer

1, 2 and 3

Question 10

Hepatitis B vaccine administered at birth is

Accepted Answer

A monovalent vaccine of Hepatitis B

Answer

A pentavalent vaccine

Answer

A fixed combination vaccine of Hepatitis B and Hib

Answer

A combined vaccine of inactivated Polio and Hepatitis B

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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