Viral Skin Infections Practice Questions

Q: What is the most common complication of chickenpox?

Bacterial infection. **Explanation:** Chickenpox (Varicella), caused by the Varicella-Zoster Virus (VZV), typically presents with a characteristic pruritic, polymorphic rash. **1. Why Bacterial Infection is Correct:** Secondary **bacterial infection** of the skin lesions is the **most common complication** of chickenpox in children. Intense scratching due to pruritus leads to excoriations, which serve as a portal of entry for skin flora. The most common causative organisms are *Staphylococcus aureus* and *Group A Beta-hemolytic Streptococcus* (Pyogenes), often manifesting as impetigo, cellulitis, or even necrotizing fasciitis. **2. Analysis of Incorrect Options:** * **Pneumonia:** While it is the most common and serious complication in **adults** (Varicella pneumonia), it is less frequent than skin infections in the general pediatric population. * **Meningitis/Encephalitis:** Neurological complications like cerebellar ataxia or encephalitis are rare. They are serious but occur much less frequently than secondary infections. * **Nephritis:** Post-varicella glomerulonephritis is an extremely rare complication. **3. Clinical Pearls for NEET-PG:** * **Most common complication (Overall/Children):** Secondary bacterial infection. * **Most common serious complication (Adults):** Varicella Pneumonia. * **Most common CNS complication:** Acute Cerebellar Ataxia (presents with "drunken gait"). * **Congenital Varicella Syndrome:** Characterized by cicatricial skin scarring, limb hypoplasia, and chorioretinitis if the mother is infected during the first 20 weeks of pregnancy. * **Tzanck Smear:** Shows Multinucleated Giant Cells (MNCs) with Cowdry Type A inclusion bodies.

Q: The characteristic rash of chickenpox exhibits which of the following distribution patterns?

Centripetal distribution. **Explanation:** Chickenpox (Varicella), caused by the **Varicella-Zoster Virus (VZV)**, is characterized by a classic rash that follows a **centripetal distribution**. This means the lesions are most concentrated on the trunk (chest, back, and abdomen) and face, with relative sparing of the distal extremities (palms and soles). **Analysis of Options:** * **Centripetal distribution (Correct):** The rash typically begins on the trunk and spreads outward, but the density remains highest centrally. This is a hallmark diagnostic feature. * **Deep seated (Incorrect):** Varicella vesicles are superficial and thin-walled, often described as "dewdrops on a rose petal." Deep-seated, firm lesions are characteristic of Smallpox (Variola). * **Monomorphic (Incorrect):** Chickenpox is **pleomorphic**. This means lesions at various stages of development (macules, papules, vesicles, and crusts) are present simultaneously in the same anatomical area. Smallpox, conversely, is monomorphic. * **Umbilicated (Incorrect):** While some varicella vesicles may show slight central depression as they crust, "umbilication" is the classic descriptor for **Molluscum Contagiosum** or Smallpox. **NEET-PG High-Yield Pearls:** * **Incubation Period:** 10–21 days. * **Infectivity:** From 1–2 days before the rash appears until all lesions have crusted over. * **Tzanck Smear:** Shows **Multinucleated Giant Cells** (also seen in Herpes Simplex). * **Complications:** Secondary bacterial infection (most common in children) and Varicella pneumonia (most common/severe in adults). * **Smallpox vs. Chickenpox:** Smallpox is centrifugal (peripheral), monomorphic, and deep-seated; Chickenpox is centripetal (central), pleomorphic, and superficial.

Q: Which skin condition typically resolves on its own?

Molluscum contagiosum. **Explanation:** **Molluscum contagiosum** is the correct answer because it is a self-limiting viral skin infection caused by the **Molluscum Contagiosum Virus (MCV)**, a member of the Poxviridae family. In immunocompetent individuals, the body’s immune system eventually recognizes the virus, leading to spontaneous resolution, typically within 6 to 12 months (though it can sometimes take longer). The characteristic lesion is a firm, pearly, flesh-colored papule with **central umbilication**. **Why the other options are incorrect:** * **Basal Cell Carcinoma (BCC):** This is a malignant skin tumor. It is locally invasive and destructive; it never resolves spontaneously and requires surgical or medical intervention. * **Psoriasis:** This is a chronic, immune-mediated inflammatory systemic disease. It is characterized by remissions and exacerbations but is generally a lifelong condition without a permanent "spontaneous cure." * **Eczema (Atopic Dermatitis):** This is a chronic relapsing inflammatory skin condition. While children may "outgrow" it as their immune system matures, the condition itself is considered a chronic trait associated with skin barrier defects (Filaggrin mutations). **Clinical Pearls for NEET-PG:** * **Histopathology:** Look for **Henderson-Paterson bodies** (intracytoplasmic eosinophilic inclusion bodies) in the epidermis. * **Transmission:** Occurs via direct contact, fomites, or autoinoculation. In adults, lesions in the anogenital region are considered a **Sexually Transmitted Infection (STI)**. * **Bohn’s Nodules vs. Molluscum:** Do not confuse umbilicated papules of Molluscum with other conditions; in HIV patients, disseminated Molluscum-like lesions should raise suspicion for **Cryptococcosis**.

Q: Which of the following conditions presents as umbilicated papules?

Molluscum contagiosum. **Explanation:** The hallmark clinical feature of **Molluscum contagiosum** is the presence of firm, pearly, flesh-colored, dome-shaped papules with a characteristic **central umbilication** (a small pit or "belly button" in the center). This condition is caused by the **Molluscum Contagiosum Virus (MCV)**, a large DNA virus belonging to the **Poxviridae** family. The umbilication corresponds to the central core of the lesion, which contains the "molluscum body" (Henderson-Paterson body)—a large intracytoplasmic inclusion body. **Analysis of Incorrect Options:** * **A. Plain warts (Verruca plana):** Caused by HPV types 3 and 10, these present as flat-topped, smooth, skin-colored or brownish papules, typically lacking umbilication. * **B. Chickenpox (Varicella):** Characterized by a "dewdrop on a rose petal" appearance (vesicles on an erythematous base). While some vesicles may crust, they do not present as firm umbilicated papules. * **C. Herpes genitalis:** Presents as clusters of painful, small, fluid-filled vesicles that quickly rupture to form shallow erosions or ulcers, rather than stable umbilicated papules. **High-Yield Clinical Pearls for NEET-PG:** * **Histopathology:** Look for **Henderson-Paterson bodies** (large, eosinophilic, intracytoplasmic inclusion bodies) in the epidermis. * **Transmission:** In children, it spreads via skin-to-skin contact or fomites; in adults, it is often considered a **Sexually Transmitted Infection (STI)**. * **HIV Association:** Giant molluscum or extensive facial lesions are a strong clinical marker for advanced **HIV/AIDS** (low CD4 count). * **Other Umbilicated Lesions:** In immunocompromised patients, fungal infections like **Cryptococcosis** and **Penicilliosis (Talaromycosis)** can also present with umbilicated papules.

Q: Dew drops on rose petal appearance is seen in infection with which of the following?

Varicella zoster virus. **Explanation:** The classic clinical description **"dew drops on rose petal"** refers to the characteristic morphology of the primary rash in **Chickenpox**, caused by the **Varicella-Zoster Virus (VZV)**. 1. **Why Varicella-Zoster Virus is correct:** The rash typically begins as small, clear, thin-walled vesicles (the "dew drop") situated on an intensely erythematous, circular base (the "rose petal"). This appearance occurs because the virus causes intraepidermal acantholysis, leading to fluid accumulation. A hallmark of VZV is **pleomorphism**, where lesions at different stages of evolution (papules, vesicles, and crusts) are seen simultaneously in the same anatomical area. 2. **Why other options are incorrect:** * **Herpes genitalis (HSV-2):** While it also presents with vesicles on an erythematous base, these are typically **grouped (herpetiform)** and painful, rather than the scattered "dew drop" distribution seen in VZV. * **Candida:** Presents as bright red erythematous plaques with characteristic **satellite lesions** (pustules at the periphery), often in intertriginous areas. * **T. rubrum:** This is a dermatophyte causing Tinea corporis/cruris, characterized by **annular plaques** with central clearing and an active, scaly border. **High-Yield Clinical Pearls for NEET-PG:** * **Tzanck Smear:** Used for rapid diagnosis of VZV and HSV; look for **Multinucleated Giant Cells** and Cowdry Type A inclusion bodies. * **Centripetal Distribution:** VZV rash starts on the trunk and spreads to the face and extremities (opposite of Smallpox). * **Ramsay Hunt Syndrome:** Reactivation of VZV in the geniculate ganglion, leading to facial palsy and vesicles in the external auditory canal.

Q: Eczema herpeticum is typically seen with which of the following viral infections?

Herpes Simplex Virus (HSV). **Explanation:** **Eczema Herpeticum** (also known as Kaposi varicelliform eruption) is a potentially life-threatening viral infection that occurs when **Herpes Simplex Virus (HSV-1 or HSV-2)** superinfects skin already compromised by a pre-existing dermatosis, most commonly **Atopic Dermatitis**. 1. **Why HSV is Correct:** In patients with impaired skin barriers (like eczema), HSV can spread rapidly across the integument. It presents clinically as "punched-out" erosions, monomorphic vesicles, and hemorrhagic crusting, often accompanied by high fever and lymphadenopathy. 2. **Why Incorrect Options are Wrong:** * **EBV (Option B):** Primarily causes Infectious Mononucleosis and Oral Hairy Leukoplakia; it does not typically cause disseminated cutaneous eruptions in atopic patients. * **CMV (Option C):** Usually causes systemic infections in immunocompromised hosts or congenital defects; cutaneous manifestations are rare and non-specific. * **VZV (Option D):** While VZV causes Varicella (chickenpox) and Herpes Zoster, the specific term "Eczema Herpeticum" is reserved for HSV. However, a similar dissemination of VZV on eczematous skin is termed *Eczema Vaccinatum* (though this historically referred to the Smallpox vaccine). **NEET-PG High-Yield Pearls:** * **Drug of Choice:** Intravenous or oral **Acyclovir** is the mainstay of treatment. * **Associated Conditions:** Besides Atopic Dermatitis, it can be seen in Darier disease, Pemphigus foliaceus, and burns. * **Diagnosis:** Tzanck smear shows **multinucleated giant cells** and Cowdry Type A inclusion bodies. * **Complication:** If untreated, it can lead to secondary bacterial infection (Staph. aureus), keratoconjunctivitis, or systemic dissemination.

Q: A 40-year-old HIV-seropositive male presents with multiple, multicentric skin lesions and lymphadenitis. What is the most likely cause of this condition?

Human Herpesvirus 8 (HHV-8). **Explanation:** The clinical presentation of multicentric skin lesions and lymphadenitis in an HIV-positive patient is highly suggestive of **Kaposi Sarcoma (KS)**. Kaposi Sarcoma is an angioproliferative disorder caused by **Human Herpesvirus 8 (HHV-8)**, also known as Kaposi Sarcoma-associated Herpesvirus (KSHV). **Why HHV-8 is correct:** In immunocompromised individuals (especially those with low CD4 counts), HHV-8 infects vascular and lymphatic endothelial cells. This leads to the formation of characteristic violaceous (purple) macules, plaques, or nodules. The "Epidemic" or AIDS-associated form is often aggressive, presenting with widespread cutaneous involvement, lymph node enlargement, and potential visceral involvement (GI tract or lungs). **Why other options are incorrect:** * **HHV-3 (Varicella-Zoster Virus):** Causes Chickenpox and Herpes Zoster (Shingles). While common in HIV patients, it presents as painful, dermatomal vesicular rashes, not multicentric vascular nodules. * **HHV-6:** Causes Roseola Infantum (Exanthem Subitum) in children. In adults/HIV patients, it may cause pneumonitis or encephalitis but is not associated with multicentric skin tumors. * **HHV-5 (Cytomegalovirus):** A common opportunistic infection in AIDS (retinitis, colitis). While it can cause skin ulcers, it does not cause the multicentric proliferative lesions seen in KS. **High-Yield Clinical Pearls for NEET-PG:** * **Histopathology:** Look for "Spindle cells," "Slit-like vascular spaces," and "Promontory sign." * **HHV-8 Associations:** Besides KS, it is linked to **Primary Effusion Lymphoma** and **Multicentric Castleman Disease**. * **Treatment:** Highly Active Antiretroviral Therapy (HAART) is the first line; systemic chemotherapy (e.g., Liposomal Doxorubicin) is used for advanced disease.

Q: The pseudo-isomorphic phenomenon is seen in which of the following dermatological conditions?

Molluscum contagiosum. **Explanation:** The **pseudo-isomorphic phenomenon** (also known as the pseudo-Koebner phenomenon) refers to the spread of infectious lesions along a line of trauma, such as scratching or shaving. Unlike the true Koebner phenomenon, which involves an inflammatory response, this occurs due to **autoinoculation** of an infectious agent into the skin. **1. Why Molluscum Contagiosum is correct:** Molluscum contagiosum is caused by a **Poxvirus**. The virus replicates within the epidermis, and when a lesion is traumatized, the infectious viral particles are mechanically spread along the scratch mark, leading to a linear distribution of new umbilicated papules. This is a classic example of autoinoculation. **2. Why the other options are incorrect:** * **A, B, and C (Psoriasis, Lichen Planus, Vitiligo):** These conditions exhibit the **True Koebner Phenomenon (Isomorphic Phenomenon)**. In these cases, non-specific trauma (like a scratch) triggers the development of new lesions of a pre-existing non-infectious skin disease in previously healthy skin. They are mediated by inflammatory and immunological pathways rather than infection. **High-Yield Clinical Pearls for NEET-PG:** * **True Koebner Phenomenon:** Seen in Psoriasis (most common), Lichen Planus, and Vitiligo. * **Pseudo-Koebner Phenomenon:** Seen in Molluscum contagiosum, Verruca (Warts), and Impetigo. * **Reverse Koebner:** Disappearance of a lesion following trauma (e.g., Psoriasis). * **Wolf’s Isotopic Response:** Occurrence of a new skin disease at the exact site of a previously healed, unrelated skin disease (most commonly seen after Herpes Zoster). * **Molluscum Contagiosum Key Feature:** Presence of **Henderson-Paterson bodies** (intracytoplasmic inclusion bodies) on histopathology.

Question 1

What is the most common complication of chickenpox?

Accepted Answer

Bacterial infection

Answer

Meningitis

Answer

Pneumonia

Answer

Nephritis

Question 2

The characteristic rash of chickenpox exhibits which of the following distribution patterns?

Accepted Answer

Centripetal distribution

Answer

Deep seated

Answer

Monomorphic

Answer

Umbilicated

Question 3

Which skin condition typically resolves on its own?

Accepted Answer

Molluscum contagiosum

Answer

Basal cell carcinoma (BCC)

Answer

Psoriasis

Answer

Eczema

Question 4

Which of the following conditions presents as umbilicated papules?

Accepted Answer

Molluscum contagiosum

Answer

Plain warts

Answer

Chickenpox

Answer

Herpes genitalis

Question 5

The skin lesions of secondary syphilis include all of the following except?

Accepted Answer

Vesicles and bullae

Answer

Macules

Answer

Nodules

Answer

Papulosquamous lesions

Question 6

Dew drops on rose petal appearance is seen in infection with which of the following?

Accepted Answer

Varicella zoster virus

Answer

Herpes genitalis

Answer

Candida

Answer

T. rubrum

Question 7

Eczema herpeticum is typically seen with which of the following viral infections?

Accepted Answer

Herpes Simplex Virus (HSV)

Answer

Epstein-Barr Virus (EBV)

Answer

Cytomegalovirus (CMV)

Answer

Varicella-Zoster Virus (VZV)

Question 8

Satellite lesion with locally invasive property is seen in which of the following conditions?

Accepted Answer

Hemangioma

Answer

Chronic hypertrophic candidiasis

Answer

Leukoplakia

Answer

Dental ulcers

Question 9

A 40-year-old HIV-seropositive male presents with multiple, multicentric skin lesions and lymphadenitis. What is the most likely cause of this condition?

Accepted Answer

Human Herpesvirus 8 (HHV-8)

Answer

Human Herpesvirus 3 (HHV-3)

Answer

Human Herpesvirus 6 (HHV-6)

Answer

Human Herpesvirus 5 (HHV-5)

Question 10

The pseudo-isomorphic phenomenon is seen in which of the following dermatological conditions?

Accepted Answer

Molluscum contagiosum

Answer

Psoriasis

Answer

Lichen planus

Answer

Vitiligo

Viral Skin Infections — MCQs

Viral Skin Infections — MCQs

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