Infectious Diseases Practice Questions

Q: A 10-week-old baby came for vaccination. The baby had a previous history of inconsolable crying and fever (40°C) after vaccination at 6 weeks. What should be given now?

Give DT only. ***Give DT only*** - The previous severe adverse reaction (**inconsolable crying** and **fever of 40°C**) is a specific contraindication to the **pertussis component** of the DPT vaccine. - According to **pediatric vaccination guidelines**, severe reactions (fever ≥40°C, inconsolable crying >3 hours) are absolute contraindications to further pertussis-containing vaccines. - The **diphtheria and tetanus toxoids** were not associated with the adverse reaction and should be safely continued. - **DT vaccine (without pertussis)** provides essential protection against diphtheria and tetanus while avoiding the problematic pertussis component. *Don't give DPT* - This option is imprecise because it doesn't specify what should be given instead. - While it correctly identifies that full DPT should be avoided, it fails to address the need for continued protection against diphtheria and tetanus. - The medically appropriate approach is to give **DT vaccine**, not to simply withhold vaccination. *Defer for 1 month* - Deferring vaccination does not address the core issue that the **pertussis component specifically** caused the severe reaction. - This approach would unnecessarily **delay protection** against diphtheria and tetanus, which the baby can safely receive immediately as DT vaccine. - The problem is not timing but the vaccine component itself. *Give DPT* - Administration of the full DPT vaccine is **absolutely contraindicated** given the history of severe adverse reactions (fever ≥40°C and inconsolable crying). - Repeating DPT risks another severe reaction and potential permanent neurological complications. - This would be a dangerous and inappropriate management decision.

Q: A child presenting with the following appearance is at risk of developing?

Pure red cell aplasia. ***Pure red cell aplasia*** - The image shows a "slapped cheek" rash, which is characteristic of **erythema infectiosum** (fifth disease) caused by **Parvovirus B19**. - Parvovirus B19 has a tropism for **erythroid progenitor cells** in the bone marrow, leading to a temporary cessation of red blood cell production, especially critical in individuals with underlying hemolytic anemias. *Immunodeficiency* - While viral infections can be more severe in immunodeficient individuals, the presented rash is specifically characteristic of **Parvovirus B19 infection**, not a general sign of immunodeficiency. - Immunodeficiency would typically involve recurrent, severe, or unusual infections, which are not directly indicated by the rash alone. *Lymphoproliferative disorder* - Lymphoproliferative disorders involve abnormal proliferation of lymphocytes and typically do not present with a "slapped cheek" rash. - Clinical signs would more likely include **lymphadenopathy**, hepatosplenomegaly, and cytopenias, not the classic facial rash seen here. *Gingivostomatitis* - **Gingivostomatitis** is an inflammation of the gums and oral mucosa, often caused by herpes simplex virus, presenting with **sores and ulcers in the mouth**. - The rash seen in the image is on the **cheeks and body**, not primarily oral, and is a classic presentation of erythema infectiosum.

Q: A child presents with fever and vesicular lesions on the upper limb and the lower limb. Neck stiffness was present. Similar lesions were present on the palms, soles, and oral cavity. CSF analysis revealed normal glucose levels and elevated lymphocytes and protein. What is the most likely diagnosis?

Coxsackie viral meningitis and Hand Foot Mouth disease. Coxsackie viral meningitis and Hand Foot Mouth disease - The presence of **vesicular lesions** on the palms, soles, and oral cavity, along with fever, is highly characteristic of **Hand Foot Mouth Disease (HFMD)** caused by Coxsackievirus. - The CSF findings of **normal glucose**, **elevated lymphocytes** (pleocytosis), and **elevated protein** are typical for **aseptic meningitis**, which is often caused by enteroviruses like Coxsackievirus [2]. *Bacterial meningitis with sepsis* - **Bacterial meningitis** would typically present with **low CSF glucose**, **high protein**, and a predominance of **neutrophils**, not lymphocytes [2]. - The characteristic vesicular rash of HFMD is not seen in bacterial meningitis. *Tuberculous meningitis* - **Tuberculous meningitis** typically has **very low CSF glucose**, **markedly elevated protein**, and a pleocytosis with a high percentage of lymphocytes. - The vesicular lesions on the palms, soles, and oral cavity are not a feature of tuberculous meningitis. *Herpes simplex gingivostomatitis and meningoencephalitis* - While **Herpes simplex** can cause **vesicular lesions** (gingivostomatitis) and **meningoencephalitis** with similar CSF findings (lymphocytic pleocytosis, elevated protein), the widespread nature of the lesions on the palms and soles is **not characteristic of HSV** [1]. - HSV lesions are typically clustered and localized to specific dermatomes or mucosal surfaces.

Q: Which of the following is given as a part of the therapy for a child with severe COVID?

Corticosteroids. ***Correct: Corticosteroids*** - **Corticosteroids** (specifically **dexamethasone**) are the **most established evidence-based therapy** for severe COVID-19 in children requiring oxygen support or mechanical ventilation - They reduce **mortality** by suppressing the hyperinflammatory response and cytokine storm associated with severe COVID-19 - Recommended by **WHO, NIH, and Indian Academy of Pediatrics (IAP)** for hospitalized children with severe COVID-19 requiring supplemental oxygen - The **RECOVERY trial** demonstrated significant mortality reduction in patients receiving oxygen therapy *Incorrect: Ivermectin* - **Ivermectin** is **NOT recommended** for COVID-19 treatment by WHO, FDA, NIH, or IAP - Multiple large randomized controlled trials (including TOGETHER trial) showed **no significant benefit** in preventing severe disease, hospitalization, or mortality - Initial in-vitro activity did not translate to clinical efficacy - Not part of standard therapy for severe COVID-19 in children *Incorrect: Remdesivir* - **Remdesivir** is an antiviral that may shorten recovery time in hospitalized adults - Evidence in **pediatric patients** is limited compared to adults - While used in some hospitalized patients, it is **not as universally recommended** as corticosteroids for severe disease - The **primary established therapy** for severe COVID-19 remains corticosteroids *Incorrect: All of the options* - Only **corticosteroids** represent standard, evidence-based therapy for severe pediatric COVID-19 - Ivermectin lacks efficacy evidence and is not recommended - The question asks what "is given as part of therapy" - corticosteroids are the definitive answer

Q: A 10-year-old boy is brought to the physician with painful and enlarged lymph nodes in his right axilla that was noticed 5 days ago and has slowly grown bigger. He has had weakness, sweating, and poor appetite during this time. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. He does not take any medication. There are no similar cases in the family. On physical exam, his temperature is 38.2°C (100.8°F), the pulse is 89/min, the respiratory rate is 13/min, and the blood pressure is 110/60 mm Hg. In his right axilla, there are multiple tender, fluctuant, and enlarged lymph nodes with overlying erythematous skin. There is a separate lesion on the child's forearm (see image). The lesion is painless to palpation and appears inflamed. Additional history should be obtained regarding which of the following?

Contact with pets. ***Contact with pets*** - The presentation of **painful, enlarged, fluctuant lymph nodes** in the axilla, accompanied by **fever and constitutional symptoms** (weakness, sweating, poor appetite), along with a **painless, inflamed lesion** (possibly a primary inoculation site, like a papule or scratch) on the forearm, is highly suggestive of **cat scratch disease**. - **Cat scratch disease** is caused by *Bartonella henselae* and is transmitted through a **scratch, bite, or lick** from an infected cat or kitten, making contact with pets a crucial piece of history. *Swimming* - While *atypical mycobacterial infections* can cause localized lymphadenitis and skin lesions, they are more commonly associated with **exposure to water** (e.g., swimming pools, fish tanks) or soil. - This option does not directly explain the specific constellation of symptoms, especially the presence of a primary **inoculation lesion** followed by regional lymphadenopathy. *Frequent infections* - While a **history of frequent infections** could raise concerns about immunodeficiency, it does not specifically point to the particular infectious etiology suggested by the patient's symptoms. - The isolated, regional nature of the lymphadenopathy following a skin lesion is more indicative of a **localized infection** like cat scratch disease rather than a systemic immune deficit. *Tick bites* - **Tick-borne illnesses** can cause fever and constitutional symptoms, but the **axillary lymphadenopathy** and the *specific appearance of the skin lesion* are not typical for most common tick-borne diseases. - For example, **Lyme disease** presents with an *erythema migrans rash* (bull's-eye pattern) and often diffuse arthralgias, not usually isolated axillary lymphadenopathy with a preceding painless papule.

Q: For a child 3-5 months of age with H1N1, treatment Oseltamivir dose is

20 mg BD X 5 days. ***20 mg BD X 5 days*** - For infants aged **3-5 months** with H1N1 influenza, the recommended dose of **Oseltamivir** is **20 mg twice daily** (BD) for **5 days**. This dosage is based on weight-based recommendations to ensure appropriate antiviral activity. - This treatment regimen is crucial for reducing the severity and duration of influenza symptoms in this vulnerable age group and should be initiated as early as possible. *12 mg BD X 5 days* - This dosage is typically recommended for younger infants, specifically those aged **less than 1 month up to 2 months** (up to 3 kg body weight). - It is **underdosing** for a child in the 3-5 months age range, which could lead to suboptimal antiviral effect. *25 mg BD X 5 days* - This dosage is generally used for children weighing **between 15 kg and 23 kg**, which is significantly higher than the average weight for an infant aged 3-5 months. - Administering this dose to a 3-5 month old would constitute an **overdose**, potentially leading to increased side effects such as nausea, vomiting, or other adverse reactions. *20 mg OD X 5 days* - While 20 mg is the correct single dose, giving it **once daily (OD)** is incorrect for treating H1N1 influenza in infants. - Oseltamivir requires a **twice-daily (BD)** regimen to maintain therapeutic drug levels and effectively inhibit viral replication over the 24-hour period.

Q: Sixth disease is?

Exanthema subitum. ***Exanthema subitum*** - Exanthema subitum, also known as **Roseola infantum** or **sixth disease**, is a common childhood illness caused by human herpesvirus 6 (HHV-6) or less commonly HHV-7. - It is characterized by **3-5 days of high fever** followed by the abrupt appearance of a **maculopapular rash** once the fever subsides. *Erythema nodosum* - **Erythema nodosum** presents as tender, red nodules, typically on the shins, and is a type of **panniculitis** (inflammation of subcutaneous fat). - It is often associated with systemic diseases, infections (e.g., strep throat, tuberculosis), drugs, or inflammatory bowel disease, rather than being a primary childhood viral exanthem. *Erythema marginatum* - **Erythema marginatum** is a rare, transient, and non-pruritic rash with **serpiginous (snake-like) borders** that is a specific hallmark of **acute rheumatic fever**. - It is not a generalized viral exanthem and does not follow a typical febrile phase like sixth disease. *Erythema Infectiosum* - **Erythema infectiosum**, also known as **fifth disease**, is caused by **parvovirus B19** and is characterized by a "slapped cheek" rash on the face followed by a lacy rash on the trunk and extremities. - While it's a common childhood exanthem, it's distinct from sixth disease in its causative agent and characteristic rash pattern.

Q: A 6-year-old child presents with hepatosplenomegaly and generalized lymphadenopathy along with fever. The child developed a rash after being administered ampicillin. What could be the possible diagnosis?

Infectious mononucleosis. ***Infectious mononucleosis*** - The combination of **hepatosplenomegaly**, **generalized lymphadenopathy**, and fever in a child is highly suggestive of infectious mononucleosis, typically caused by the **Epstein-Barr virus (EBV)**. - A characteristic feature is the development of a **maculopapular rash** following the administration of ampicillin or amoxicillin. *Kawasaki disease* - Characterized by **fever**, generalized rash, lymphadenopathy, and mucocutaneous inflammation, but typically does not involve significant **hepatosplenomegaly**. - The rash in Kawasaki disease is not typically triggered by **ampicillin**. *Scarlet fever* - Caused by a **Streptococcus pyogenes** infection and presents with a characteristic **sandpaper-like rash**, **strawberry tongue**, and fever. - It usually does not involve significant **hepatosplenomegaly** or a rash specifically induced by ampicillin. *HIV infection* - While HIV can cause **generalized lymphadenopathy** and **hepatosplenomegaly**, especially in children, the sudden onset of a rash specifically after ampicillin administration is not a hallmark of acute or chronic HIV infection. - Other opportunistic infections and **growth failure** would likely be present in advanced HIV.

Q: Koplik spots are seen in?

Measles. ***Measles*** - **Koplik spots** are pathognomonic rash that appears as small, white spots with a bluish-white center on an erythematous base on the **buccal mucosa** opposite the second molars. - They typically appear 2-3 days before the onset of the characteristic maculopapular rash, during the **prodromal phase** of measles (rubeola). *Rubella* - Rubella, or **German measles**, presents with a milder rash, **lymphadenopathy**, and mild fever. - It does not cause Koplik spots; instead, **Forchheimer spots** (petechiae on the soft palate) may be seen, but these are less specific. *Mumps* - Mumps is characterized primarily by **parotitis** (swelling of the salivary glands), fever, and headache. - It does not present with Koplik spots or any characteristic oral mucosal lesions. *Varicella* - Varicella, or **chickenpox**, is characterized by a **vesicular rash** that progresses from macules to papules to vesicles to crusts, appearing in crops. - It does not involve Koplik spots; the rash is typically generalized and pruritic.

Q: Most common cause of post-measles death?

Pneumonia. ***Pneumonia*** - **Pneumonia**, particularly secondary bacterial pneumonia, is the **most common cause of death** in children following a measles infection. - Measles causes **immune suppression** and damage to the respiratory epithelium, making individuals vulnerable to severe respiratory infections. *SSPE* - **Subacute sclerosing panencephalitis (SSPE)** is a rare, fatal, late complication of measles, occurring years after the initial infection. - While always fatal, its rarity means it is not the most common cause of overall measles-related mortality. *Myocarditis* - **Myocarditis**, inflammation of the heart muscle, can be a rare complication of measles, but it is not the leading cause of death. - Cardiac complications are less frequently observed as the primary cause of death compared to respiratory infections. *Diarrhea* - **Diarrhea** is a common complication of measles, especially in malnourished children, and can contribute to mortality due to **dehydration** and electrolyte imbalances. - However, severe respiratory complications like pneumonia are still responsible for a higher proportion of measles-related deaths.

Question 1

A 10-week-old baby came for vaccination. The baby had a previous history of inconsolable crying and fever (40°C) after vaccination at 6 weeks. What should be given now?

Accepted Answer

Give DT only

Answer

Don't give DPT

Answer

Defer for 1 month

Answer

Give DPT

Question 2

A child presenting with the following appearance is at risk of developing?

Accepted Answer

Pure red cell aplasia

Answer

Immunodeficiency

Answer

Lymphoproliferative disorder

Answer

Gingivostomatitis

Question 3

A child presents with fever and vesicular lesions on the upper limb and the lower limb. Neck stiffness was present. Similar lesions were present on the palms, soles, and oral cavity. CSF analysis revealed normal glucose levels and elevated lymphocytes and protein. What is the most likely diagnosis?

Accepted Answer

Coxsackie viral meningitis and Hand Foot Mouth disease

Answer

Bacterial meningitis with sepsis

Answer

Tuberculous meningitis

Answer

Herpes simplex gingivostomatitis and meningoencephalitis

Question 4

Which of the following is given as a part of the therapy for a child with severe COVID?

Accepted Answer

Corticosteroids

Answer

Ivermectin

Answer

Remdesivir

Answer

All of the options

Question 5

A 10-year-old boy is brought to the physician with painful and enlarged lymph nodes in his right axilla that was noticed 5 days ago and has slowly grown bigger. He has had weakness, sweating, and poor appetite during this time. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. He does not take any medication. There are no similar cases in the family. On physical exam, his temperature is 38.2°C (100.8°F), the pulse is 89/min, the respiratory rate is 13/min, and the blood pressure is 110/60 mm Hg. In his right axilla, there are multiple tender, fluctuant, and enlarged lymph nodes with overlying erythematous skin. There is a separate lesion on the child's forearm (see image). The lesion is painless to palpation and appears inflamed. Additional history should be obtained regarding which of the following?

Accepted Answer

Contact with pets

Answer

Swimming

Answer

Frequent infections

Answer

Tick bites

Question 6

For a child 3-5 months of age with H1N1, treatment Oseltamivir dose is

Accepted Answer

20 mg BD X 5 days

Answer

12 mg BD X 5 days

Answer

25 mg BD X 5 days

Answer

20 mg OD X 5 days

Question 7

Sixth disease is?

Accepted Answer

Exanthema subitum

Answer

Erythema nodosum

Answer

Erythema marginatum

Answer

Erythema Infectiosum

Question 8

A 6-year-old child presents with hepatosplenomegaly and generalized lymphadenopathy along with fever. The child developed a rash after being administered ampicillin. What could be the possible diagnosis?

Accepted Answer

Infectious mononucleosis

Answer

Kawasaki disease

Answer

Scarlet fever

Answer

HIV infection

Question 9

Koplik spots are seen in?

Accepted Answer

Measles

Answer

Rubella

Answer

Mumps

Answer

Varicella

Question 10

Most common cause of post-measles death?

Accepted Answer

Pneumonia

Answer

SSPE

Answer

Myocarditis

Answer

Diarrhea

Infectious Diseases — MCQs

Infectious Diseases — MCQs

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