Childhood Exanthems — MCQs
All of the following are true about erythema infectiosum EXCEPT?
Pathognomonic of measles?
The etiological agent for roseola infantum is:
True about measles
Sixth disease is?
A neonate who is febrile, presents with features of encephalitis. On examination, the baby is found to have vesicular skin lesions. Most probable causative organism is:
Identify the lesion: (Recent NEET Pattern 2016-17)
A child presents with a history of hypopigmented macules on the back, infantile spasms, and delayed milestones. What is the most likely diagnosis?
A 14-year-old boy presents with seizures and skin macules. What is the probable diagnosis?
In infancy, atopic dermatitis typically spares which of the following areas?
Childhood Exanthems Indian Medical PG Practice Questions and MCQs
Question 1: All of the following are true about erythema infectiosum EXCEPT?
- A. Caused by parvovirus
- B. Known as 'fifth disease'
- C. Rash initially appears on trunk (Correct Answer)
- D. Slapped cheek appearance seen
Explanation: ***Rash initially appears on trunk*** - Erythema infectiosum (fifth disease) characteristically begins with a **'slapped cheek' rash** on the face. - The rash then spreads to the trunk and extremities, taking on a **lacy, reticulated appearance**, but it does not initially appear on the trunk. *Caused by parvovirus* - Erythema infectiosum is caused by **Parvovirus B19**, which primarily infects erythroid progenitor cells. - This virus is highly contagious and spreads via respiratory secretions. *Known as 'fifth disease'* - Erythema infectiosum is one of the classic childhood exanthems and is historically known as **'fifth disease'**. - The numbering sequence refers to the order in which these common childhood rashes were identified. *Slapped cheek appearance seen* - A prominent feature of erythema infectiosum is the classic bright red rash on the cheeks, giving the child a distinctive **'slapped cheek' appearance**. - This facial rash often precedes the lacy rash on the body.
Question 2: Pathognomonic of measles?
- A. Koplik spot (Correct Answer)
- B. Rash
- C. Conjunctivitis
- D. Fever
Explanation: ***Koplik spot*** - **Koplik spots** are tiny, white spots with a bluish-white center found on the buccal mucosa opposite the molars; they are **pathognomonic** for measles [1]. - The appearance of Koplik spots often precedes the characteristic measles rash by 1-2 days and helps in early diagnosis [1]. *Rash* - While a **maculopapular rash** is a prominent feature of measles [1], it is not pathognomonic as similar rashes can be seen in other viral exanthems. - The measles rash typically starts on the face and behind the ears, spreading downwards, but its presence alone is insufficient for a definitive diagnosis. *Conjunctivitis* - **Conjunctivitis** is a common symptom in measles, contributing to the "3 C's" (cough, coryza, conjunctivitis), but it is a non-specific finding seen in many other viral illnesses. - It presents as red, watery eyes and is part of the prodromal phase but does not uniquely identify measles. *Fever* - **Fever** is a universal symptom of measles, usually high-grade, but it is a general sign of infection and not specific to measles. - Many viral and bacterial infections cause fever, making it a poor diagnostic indicator on its own.
Question 3: The etiological agent for roseola infantum is:
- A. Epstein-Barr Virus (EBV)
- B. Cytomegalovirus (CMV)
- C. Human Herpesvirus 6 (HHV-6) (Correct Answer)
- D. Adenovirus
Explanation: ***Human Herpesvirus 6 (HHV-6)*** - **HHV-6** is the primary cause of **roseola infantum**, also known as exanthem subitum. - This virus is responsible for the characteristic high fever followed by a rash often seen in infants and young children. *Epstein-Barr Virus (EBV)* - **EBV** is the causative agent of **infectious mononucleosis**, not roseola infantum. - While both are herpesviruses, their clinical presentations and target cell specificities differ significantly. *Cytomegalovirus (CMV)* - **CMV** is another herpesvirus that can cause a variety of symptoms, especially in immunocompromised individuals or congenitally. - It is not typically associated with the classic presentation of **roseola infantum**. *Adenovirus* - **Adenoviruses** are a common cause of respiratory infections, conjunctivitis, and gastroenteritis. - They do not cause **roseola infantum**, which is characterized by a specific fever-rash sequence.
Question 4: True about measles
- A. Long term complication follows in form of SSPE (Correct Answer)
- B. Rash appear first on leg
- C. Koplik spots are seen in retina
- D. Caused by DNA virus
Explanation: ***Long term complication follows in form of SSPE*** - **Subacute sclerosing panencephalitis (SSPE)** is a rare, but fatal, progressive neurodegenerative disease that can develop years after a measles infection [1]. - It is caused by persistent measles virus in the brain, leading to **neurological deterioration** and eventually death [2]. *Rash appear first on leg* - The characteristic rash of measles typically appears first on the **face and behind the ears**, then spreads downward to the trunk and extremities [1]. - The rash is usually **maculopapular** and confluent, turning brownish and fading in the same order it appeared [1]. *Koplik spots are seen in retina* - **Koplik spots** are pathognomonic for measles and are found on the **buccal mucosa** (inside the cheeks), opposite the molars [1]. - They appear as small, white, or bluish-white spots with an erythematous base before the onset of the rash. *Caused by DNA virus* - Measles is caused by the **measles virus**, which is a **single-stranded RNA virus** belonging to the genus *Morbillivirus* in the family *Paramyxoviridae*. - It is not a DNA virus; this classification has significant implications for its replication cycle and vaccine development.
Question 5: Sixth disease is?
- A. Erythema nodosum
- B. Erythema marginatum
- C. Erythema Infectiosum
- D. Exanthema subitum (Correct Answer)
Explanation: ***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.
Question 6: A neonate who is febrile, presents with features of encephalitis. On examination, the baby is found to have vesicular skin lesions. Most probable causative organism is:
- A. Meningococci
- B. Streptococci
- C. HSV I
- D. HSV II (Correct Answer)
Explanation: ***HSV II*** - **Herpes simplex virus type 2 (HSV-2)** is the most common cause of **neonatal herpes**, presenting with neurological manifestations like encephalitis and characteristic vesicular skin lesions. - Transmission usually occurs during **vaginal delivery** from a mother with genital herpes, leading to widespread infection in the neonate. *Meningococci* - While *Neisseria meningitidis* can cause **meningitis** and **septicemia** in neonates, it does not typically produce vesicular skin lesions. - Its infections are more commonly associated with a **petechial or purpuric rash**, not vesicles. *Streptococci* - **Group B Streptococcus (GBS)** is a leading cause of **neonatal sepsis and meningitis**, but it does not cause vesicular skin lesions. - GBS typically presents with non-specific signs of sepsis or meningitis in neonates. *HSV I* - Although **herpes simplex virus type 1 (HSV-1)** can cause neonatal herpes, **HSV-2 remains the predominant cause** of vertically transmitted neonatal infection with encephalitis and disseminated disease. - HSV-1 is more commonly associated with **oral herpes (cold sores)** in older children and adults, though its incidence in neonatal infection is increasing.
Question 7: Identify the lesion: (Recent NEET Pattern 2016-17)
- A. Erythema multiforme (Correct Answer)
- B. Gianotti-Crosti syndrome
- C. Pityriasis rosea
- D. Acne rosacea
Explanation: ***Erythema multiforme*** - The image displays characteristic **targetoid lesions** with multiple concentric rings of color (erythema, edema, pallor), typical of **erythema multiforme**. - These lesions often appear suddenly, symmetrically, and commonly on the extremities, often triggered by infections (e.g., **herpes simplex virus**) or medications. *Gianotti-Crosti syndrome* - Characterized by **monomorphic, flesh-colored to erythematous papules** and papulovesicles, often on the cheeks, buttocks, and extensor surfaces of the limbs. - This condition is typically observed in **children** after viral infections and does not usually present with target lesions. *Pityriasis rosea* - Starts with a single **"herald patch,"** followed by smaller, oval, pinkish-red patches with fine scales, often arranged in a **"Christmas tree pattern"** on the trunk. - The morphology of the lesions in the image, specifically the targetoid appearance, is not consistent with pityriasis rosea. *Acne rosacea* - Marked by **facial erythema**, papules, pustules, and telangiectasias, primarily affecting the central face. - It does not present with the widespread, distinct target lesions seen in the image.
Question 8: A child presents with a history of hypopigmented macules on the back, infantile spasms, and delayed milestones. What is the most likely diagnosis?
- A. Neurofibromatosis
- B. Sturge-Weber syndrome
- C. Tuberous sclerosis (Correct Answer)
- D. Nevus anemicus
Explanation: ### Explanation **Correct Answer: C. Tuberous Sclerosis (TSC)** The clinical triad of **hypopigmented macules (Ash-leaf spots)**, **infantile spasms** (West Syndrome), and **delayed milestones** is classic for Tuberous Sclerosis Complex. * **Pathophysiology:** TSC is an autosomal dominant neurocutaneous syndrome caused by mutations in the *TSC1* (Hamartin) or *TSC2* (Tuberin) genes, leading to the overactivation of the mTOR pathway and the formation of hamartomas in multiple organs. * **Dermatological markers:** Ash-leaf spots are often the earliest sign. Other features include Adenoma sebaceum (angiofibromas), Shagreen patches (connective tissue nevi), and periungual fibromas (Koenen tumors). * **Neurological markers:** Cortical tubers and subependymal nodules lead to seizures (infantile spasms) and intellectual disability. **Why Incorrect Options are Wrong:** * **A. Neurofibromatosis:** Characterized by *hyperpigmented* Café-au-lait macules, Lisch nodules, and neurofibromas, rather than hypopigmentation and infantile spasms. * **B. Sturge-Weber Syndrome:** Presents with a Port-wine stain (Nevus Flammeus) in the V1/V2 distribution of the trigeminal nerve, glaucoma, and leptomeningeal angiomas. * **C. Nevus Anemicus:** A localized vascular anomaly presenting as a pale patch due to catecholamine sensitivity. It does not cause systemic neurological symptoms or developmental delay. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest sign:** Ash-leaf spots (best seen under **Wood’s lamp**). * **Most common heart lesion:** Rhabdomyoma (often regresses spontaneously). * **Most common kidney lesion:** Angiomyolipoma. * **Drug of choice for Infantile Spasms in TSC:** Vigabatrin. * **Pathognomonic sign:** Koenen tumors (Periungual fibromas).
Question 9: A 14-year-old boy presents with seizures and skin macules. What is the probable diagnosis?
- A. Sturge-Weber syndrome
- B. Turcot syndrome
- C. Tuberous sclerosis (Correct Answer)
- D. Von Hippel-Lindau disease
Explanation: ### Explanation **Correct Answer: C. Tuberous Sclerosis (TSC)** The combination of **seizures** and **skin macules** (specifically hypopigmented "Ash-leaf" spots) is a classic presentation of Tuberous Sclerosis Complex, a neurocutaneous syndrome inherited in an autosomal dominant fashion (TSC1/TSC2 gene mutations). * **Why it is correct:** In pediatric dermatology, the earliest sign of TSC is often the **Ash-leaf macule** (hypopigmented macules visible under Wood’s lamp). The involvement of the Central Nervous System leads to cortical tubers and subependymal nodules, which manifest clinically as **seizures** and intellectual disability (the "Vogt’s Triad": Seizures, Mental Retardation, and Adenoma Sebaceum). **Analysis of Incorrect Options:** * **A. Sturge-Weber Syndrome:** Characterized by a **Port-wine stain** (Nevus Flammeus) usually in the V1/V2 distribution of the trigeminal nerve. While it causes seizures, the skin lesion is a vascular malformation, not a macule. * **B. Turcot Syndrome:** A variant of Familial Adenomatous Polyposis (FAP) associated with CNS tumors (medulloblastoma/glioma) and colonic polyps. It does not typically present with characteristic skin macules. * **C. Von Hippel-Lindau (VHL) Disease:** Characterized by hemangioblastomas (retina/cerebellum) and renal cell carcinoma. It lacks the specific cutaneous macules associated with seizures in childhood. **High-Yield Clinical Pearls for NEET-PG:** 1. **Skin Findings in TSC:** Ash-leaf spots (earliest), Adenoma Sebaceum (angiofibromas), Shagreen patches (connective tissue nevi), and Periungual fibromas (Koenen tumors). 2. **Diagnostic Triad (Vogt’s):** Epilepsy, Low IQ, and Adenoma Sebaceum (only present in ~30% of cases). 3. **Other Associations:** Cardiac rhabdomyomas (often regress), Renal Angiomyolipomas (AML), and Lymphangioleiomyomatosis (LAM) in the lungs. 4. **Wood’s Lamp:** Essential for identifying Ash-leaf spots in fair-skinned children.
Question 10: In infancy, atopic dermatitis typically spares which of the following areas?
- A. Extensor surfaces
- B. Forehead
- C. Scalp
- D. Diaper area (Correct Answer)
Explanation: **Explanation:** Atopic Dermatitis (AD) is a chronic, pruritic inflammatory skin disease that follows a characteristic age-dependent distribution. In **infancy** (birth to 2 years), the correct answer is the **Diaper area (Option D)**. **Why the Diaper Area is Spared:** The diaper area is typically spared in infantile AD because the high humidity and moisture trapped by the diaper prevent skin dehydration (transepidermal water loss). Since xerosis (dryness) is a primary trigger for AD, the "occlusive" effect of the diaper protects this specific region. If a rash is present in the diaper area, clinicians should consider Seborrheic Dermatitis or Irritant Diaper Dermatitis instead. **Analysis of Incorrect Options:** * **A. Extensor surfaces:** These are the classic sites for AD in infants. As babies begin to crawl, the friction on the knees and elbows triggers the "itch-scratch cycle." * **B. Forehead & C. Scalp:** The face (especially the cheeks and forehead) and the scalp are often the first sites involved in infancy. The lesions are typically acute, presenting as erythematous, edematous, and sometimes weeping plaques. **High-Yield Clinical Pearls for NEET-PG:** * **Evolution of Sites:** * **Infancy:** Face, scalp, and extensors (spares diaper area). * **Childhood/Adulthood:** Flexural surfaces (antecubital and popliteal fossae), neck, and wrists. * **Hertoghe’s Sign:** Thinning of the lateral third of the eyebrows (due to chronic rubbing). * **Dennie-Morgan Fold:** An extra fold of skin under the lower eyelid. * **Filaggrin (FLG) Mutation:** The most common genetic defect associated with skin barrier dysfunction in AD.
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