Viral Skin Infections Practice Questions

Q: Which of the following statements is NOT true regarding the skin condition shown in the figure?

It is common in the elderly.. ***It is common in the elderly.*** - **Molluscum contagiosum** primarily affects **children** and **young adults**, not the elderly population. - The condition is most prevalent in patients under **20 years of age**, making this statement false. *It occurs due to a viral infection.* - **Molluscum contagiosum** is caused by the **Molluscum Contagiosum Virus (MCV)**, a **poxvirus**. - The virus causes characteristic **dome-shaped papules** with **central umbilication**. *It can occur in individuals with a normal immune status.* - **Immunocompetent individuals** frequently develop molluscum contagiosum, especially children. - While **immunocompromised patients** may have more extensive disease, normal immunity does not prevent infection. *It can be transmitted as a sexually transmitted disease.* - In **adults**, molluscum contagiosum is commonly transmitted through **sexual contact**. - **Genital lesions** in adults are typically acquired through intimate skin-to-skin contact.

Q: A patient presents with recurrent palatal pain, multiple punctate ulcers in the hard palate that were preceded by tiny blisters. Her lesions typically heal in about 2 weeks and reappear during stressful times. What is the most likely diagnosis?

Recurrent secondary herpes. ### Explanation The clinical presentation of recurrent, grouped punctate ulcers on the **keratinized mucosa** (hard palate) preceded by vesicles is pathognomonic for **Recurrent Secondary Herpes (Recurrent Herpes Simplex)**. **1. Why the correct answer is right:** After a primary infection, the Herpes Simplex Virus (HSV-1) remains latent in the sensory ganglia (trigeminal ganglion). Upon reactivation by triggers like **stress**, sunlight, or trauma, the virus travels back to the skin/mucosa. Unlike primary herpes, which is widespread, secondary herpes is localized. A key diagnostic feature is its location: **Recurrent intraoral herpes almost exclusively involves keratinized tissues** (hard palate and gingiva), whereas aphthous ulcers involve non-keratinized tissue. **2. Why other options are wrong:** * **Aphthous ulcers:** These are common but typically occur on **non-keratinized mucosa** (buccal mucosa, labial mucosa, floor of the mouth). They are not preceded by vesicles and do not involve the hard palate. * **Recurrent primary herpes:** This is a contradictory term. "Primary" refers to the initial exposure (Gingivostomatitis), which is usually more severe, involves high fever, and occurs only once. * **Erythema multiforme:** This presents with "target lesions" on the skin and extensive, hemorrhagic crusting of the lips. While it can be triggered by HSV, the oral lesions are typically large, irregular erosions rather than tiny punctate ulcers on the hard palate. **3. NEET-PG High-Yield Pearls:** * **Location Rule:** HSV = Keratinized tissue (Hard palate/Gingiva); Aphthous = Non-keratinized (Soft palate/Cheeks). * **Tzanck Smear:** Look for **Multinucleated Giant Cells** and **Acantholysis**. * **Inclusion Bodies:** Cowdry Type A (Lipschütz bodies) are characteristic of HSV. * **Treatment:** Oral Acyclovir or Valacyclovir is most effective if started during the prodromal phase.

Q: A 3-year-old female child develops umbilicated nodules over the face following a trivial viral infection. What is the probable diagnosis?

Molluscum contagiosum. **Explanation:** The clinical presentation of **umbilicated nodules** (pearly, flesh-colored papules with a central dimple) is the classic hallmark of **Molluscum contagiosum**. **1. Why Molluscum contagiosum is correct:** It is caused by the **Molluscum Contagiosum Virus (MCV)**, a member of the **Poxviridae** family. It typically affects children (via direct contact) and sexually active adults. The characteristic "umbilication" represents the central viral core. In children, it often follows a period of mild immunosuppression or skin barrier breakdown (like a viral prodrome or atopic dermatitis). **2. Why other options are incorrect:** * **Lichen planus:** Presents as the "6 Ps": Purple, Planar (flat-topped), Polygonal, Pruritic, Papules, and Plaques. It features **Wickham striae**, not umbilication. * **Chicken Pox (Varicella):** Characterized by a pleomorphic rash (macules, papules, and vesicles in different stages) described as **"dewdrops on a rose petal."** While vesicles may crust, they are not persistent umbilicated nodules. * **Scabies:** Caused by *Sarcoptes scabiei*, presenting with intense nocturnal itching and **burrows** in web spaces. It does not present with umbilicated nodules. **Clinical Pearls for NEET-PG:** * **Histopathology:** Look for **Henderson-Paterson bodies** (large, intracytoplasmic eosinophilic inclusion bodies). * **In Adults:** If extensive molluscum is seen on the face of an adult, always screen for **HIV/Immunosuppression**. * **Treatment:** Usually self-limiting, but can be treated with curettage, cryotherapy, or expression of the central curd-like core.

Q: Genital Warts are seen in:

Buschke Lowenstein tumour. **Explanation:** **Genital Warts (Condyloma Acuminata)** are caused by the Human Papillomavirus (HPV), most commonly types 6 and 11. **Why Buschke-Lowenstein Tumour is correct:** The **Buschke-Lowenstein Tumour**, also known as **Giant Condyloma Acuminatum**, is a rare, large, cauliflower-like growth that represents a locally aggressive variant of genital warts. While it is histologically benign (it does not metastasize), it is characterized by massive size, deep local infiltration into underlying tissues, and a high rate of recurrence. It is strongly associated with HPV types 6 and 11. **Why other options are incorrect:** * **Syphilis:** Primary syphilis presents as a painless **chancre**. Secondary syphilis presents with **Condyloma Lata**, which are flat, moist, highly infectious papules. These should not be confused with the "acuminate" (pointed/warty) appearance of genital warts. * **Leprosy:** Caused by *Mycobacterium leprae*, it primarily affects the skin and peripheral nerves, presenting as hypopigmented patches or nodules (lepromas), not warty genital lesions. * **TB (Tuberculosis):** Cutaneous TB (like Lupus Vulgaris or Tuberculosis Verrucosa Cutis) presents with apple-jelly nodules or verrucous plaques, but it is not a cause of genital warts. **High-Yield Clinical Pearls for NEET-PG:** * **Causative Agent:** HPV 6, 11 (Low risk); HPV 16, 18 (High risk for malignancy). * **Histopathology:** Look for **Koilocytes** (cells with perinuclear halo and wrinkled "raisinoid" nuclei). * **Treatment of choice:** Podophyllin, Imiquimod, or Cryotherapy. * **Buschke-Lowenstein:** Despite its aggressive local behavior, it is considered a **Verrucous Carcinoma**.

Q: All of the following are true regarding viral warts except:

Verruca vulgaris is associated with HPV 7. **Explanation:** Viral warts (Verrucae) are benign proliferations of the skin and mucosa caused by the **Human Papillomavirus (HPV)**. **Why Option D is the correct answer (The False Statement):** Verruca vulgaris (common warts) is primarily associated with **HPV types 2, 4, and 1**. While HPV 7 is indeed a cause of warts, it is specifically associated with **"Butcher’s warts"** (found in individuals who handle raw meat/poultry), not the typical presentation of Verruca vulgaris. **Analysis of other options:** * **Option A (Basophilic stippling):** Histopathology of warts often shows prominent keratohyalin granules and viral inclusion bodies, which appear as basophilic stippling within the cells. * **Option B (Koilocytes):** These are the hallmark histological feature of HPV infection. Koilocytes are squamous epithelial cells with perinuclear halos and shrunken, "raisin-like" pyknotic nuclei. * **Option C (Spontaneous regression):** In children, approximately two-thirds of warts resolve spontaneously within two years due to the development of cell-mediated immunity. **High-Yield Clinical Pearls for NEET-PG:** * **Verruca Plana (Flat warts):** Associated with HPV 3 and 10. * **Plantar Warts (Myrmecia):** Associated with HPV 1. * **Condyloma Acuminata (Anogenital):** HPV 6 and 11 (Low risk); HPV 16 and 18 (High risk for malignancy). * **Auspitz Sign vs. Warts:** While Psoriasis shows Auspitz sign, paring a wart reveals **punctate bleeding points** (thrombosed capillaries), which is a diagnostic clinical sign.

Q: What is the most common cause of erythema multiforme?

Herpes simplex virus. **Explanation:** **Erythema Multiforme (EM)** is an acute, self-limiting Type IV hypersensitivity reaction. The most common trigger, accounting for up to 90% of cases, is an infection. 1. **Why Herpes Simplex Virus (HSV) is correct:** HSV (specifically HSV-1) is the **most common cause** of Erythema Multiforme Minor. Viral DNA fragments are transported to the skin by circulating mononuclear cells, triggering a T-cell mediated immune response against keratinocytes. Recurrent EM is almost always associated with recurrent HSV outbreaks. 2. **Analysis of Incorrect Options:** * **Mycoplasma pneumoniae:** This is the most common **bacterial** cause of EM. It is more frequently associated with **EM Major** (involving mucosal surfaces) and is a common trigger in the pediatric population, but it is less frequent than HSV overall. * **Varicella zoster virus & Influenza virus:** While many viruses can theoretically trigger EM, these are rare causes and do not represent the primary epidemiological driver of the disease. **Clinical Pearls for NEET-PG:** * **Morphology:** The hallmark lesion is the **"Target" or "Iris" lesion**, consisting of three concentric zones: a dusky central disk (sometimes blistered), a pale edematous ring, and an erythematous outer halo. * **Distribution:** Lesions typically appear symmetrically on the **acral extremities** (palms and soles). * **EM Minor vs. Major:** EM Minor involves little to no mucosal involvement; EM Major involves at least two mucosal surfaces (usually oral) and systemic symptoms. * **Drug Triggers:** While infections are the primary cause, drugs (NSAIDs, Sulfonamides, Antiepileptics) are the second most common trigger.

Q: Microscopy of a Tzank smear from a patient presenting with a shin vesicle showed giant cells. What is the causative agent?

Varicella zoster. **Explanation:** The presence of **multinucleated giant cells** on a Tzanck smear is a hallmark diagnostic finding for infections caused by the **Herpesviridae** family, specifically Herpes Simplex Virus (HSV-1, HSV-2) and **Varicella-Zoster Virus (VZV)**. The Tzanck smear is performed by scraping the base of a freshly opened vesicle. Under the microscope (stained with Giemsa or Wright stain), one observes "Tzanck cells," which are large, multinucleated keratinocytes formed by the fusion of infected cells (syncytia) and characteristic "ground-glass" nuclei with peripheral chromatin condensation. **Analysis of Options:** * **Varicella Zoster (Correct):** As a member of the Alpha-herpesvirinae subfamily, it typically presents with vesicular eruptions (Chickenpox or Shingles) and shows positive Tzanck smear findings. * **Vaccinia Virus:** A Poxvirus used in smallpox vaccines. It produces **Guarnieri bodies** (intracytoplasmic eosinophilic inclusions), not multinucleated giant cells. * **Tuberculosis:** Cutaneous TB (like Lupus Vulgaris) shows granulomatous inflammation with Langhans giant cells on histopathology, but it does not present with acute vesicles or a positive Tzanck smear. * **Molluscum Contagiosum:** Caused by a Poxvirus, it presents with umbilicated papules. Microscopy reveals **Henderson-Paterson bodies** (large, intracytoplasmic viral inclusion bodies). **NEET-PG High-Yield Pearls:** 1. **Tzanck Smear Mnemonic:** Remember **"3H"** – **H**SV, **H**ZV, and **H**ailey-Hailey disease/Pemphigus (acantholytic cells). 2. **Inclusion Bodies:** HSV/VZV show **Cowdry Type A** intranuclear inclusions. 3. **Limitation:** A Tzanck smear can identify a Herpes group infection but **cannot differentiate** between HSV-1, HSV-2, and VZV. Viral culture or PCR is required for specific typing.

Q: A patient presents with painful blisters along the chest wall. All of the following tests are useful for diagnosis except?

LDH levels. **Explanation:** The clinical presentation of painful blisters along a dermatome (chest wall) is characteristic of **Herpes Zoster (Shingles)**, caused by the reactivation of the Varicella-Zoster Virus (VZV). **Why LDH levels is the correct answer:** Lactate Dehydrogenase (LDH) is a non-specific marker of tissue damage or hemolysis. While it may be elevated in certain malignancies or severe systemic infections, it has **no diagnostic utility** in identifying viral skin infections like Herpes Zoster. Diagnosis of VZV is primarily clinical or confirmed through virus-specific laboratory methods. **Analysis of other options:** * **Tzanck Smear:** A rapid, bedside test where a scraping from the base of the vesicle is stained (e.g., Giemsa). It reveals **multinucleated giant cells** and Cowdry Type A inclusion bodies, characteristic of the Herpesviridae family. * **Direct Fluorescent Antibody (DFA):** This involves using fluorescein-labeled antibodies to detect specific viral antigens in skin scrapings. It is more sensitive and specific than the Tzanck smear. * **Polymerase Chain Reaction (PCR):** This is the **gold standard** and the most sensitive method for detecting VZV DNA from vesicle fluid or crusts. **NEET-PG High-Yield Pearls:** * **Cowdry Type A bodies:** Intranuclear eosinophilic inclusion bodies seen in HSV and VZV. * **Tzanck Smear limitation:** It can identify the Herpes family but **cannot differentiate** between HSV-1, HSV-2, and VZV. * **Dermatomal distribution:** VZV stays latent in the **dorsal root ganglia**; its reactivation follows a specific nerve distribution (unilateral). * **Post-herpetic neuralgia:** The most common complication of Shingles, especially in the elderly.

Question 1

Which of the following statements is NOT true regarding the skin condition shown in the figure?

Accepted Answer

It is common in the elderly.

Answer

It occurs due to a viral infection.

Answer

It can occur in individuals with a normal immune status.

Answer

It can be transmitted as a sexually transmitted disease.

Question 2

A patient presents with recurrent palatal pain, multiple punctate ulcers in the hard palate that were preceded by tiny blisters. Her lesions typically heal in about 2 weeks and reappear during stressful times. What is the most likely diagnosis?

Accepted Answer

Recurrent secondary herpes

Answer

Aphthous ulcers

Answer

Recurrent primary herpes

Answer

Erythema multiforme

Question 3

A 3-year-old female child develops umbilicated nodules over the face following a trivial viral infection. What is the probable diagnosis?

Accepted Answer

Molluscum contagiosum

Answer

Lichen planus

Answer

Chicken Pox

Answer

Scabies

Question 4

Genital Warts are seen in:

Accepted Answer

Buschke Lowenstein tumour

Answer

Syphilis

Answer

Leprosy

Answer

TB

Question 5

All of the following are true regarding viral warts except:

Accepted Answer

Verruca vulgaris is associated with HPV 7

Answer

Basophilic stippling

Answer

Koilocytes are characteristic

Answer

Spontaneous regression is common in children

Question 6

Recurrent lesions on the glans that heal with residual hyperpigmentation are suggestive of:

Accepted Answer

Herpes genitalis

Answer

Aphthous ulcer

Answer

Fixed drug eruption

Answer

Chlamydial infection

Question 7

What is the most common cause of erythema multiforme?

Accepted Answer

Herpes simplex virus

Answer

Mycoplasma pneumoniae

Answer

Varicella zoster virus

Answer

Influenza virus

Question 8

Microscopy of a Tzank smear from a patient presenting with a shin vesicle showed giant cells. What is the causative agent?

Accepted Answer

Varicella zoster

Answer

Vaccinia virus

Answer

Tuberculous

Answer

Molluscum contagiosum

Question 9

A patient presents with painful blisters along the chest wall. All of the following tests are useful for diagnosis except?

Accepted Answer

LDH levels

Answer

Direct Fluorescent antibody

Answer

Polymerase chain reaction

Answer

Tzank smear

Question 10

A young patient complains of shooting pain, paresthesia, and tenderness on one side of the palate. Unilateral vesicles appear in clusters. The patient gives a previous history of chickenpox. What is the most likely diagnosis?

Accepted Answer

Herpes zoster

Answer

Herpes simplex

Answer

Herpangina

Answer

Behçet's syndrome

Viral Skin Infections — MCQs

Viral Skin Infections — MCQs

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