Viral Skin Infections — MCQs

Viral Skin Infections Indian Medical PG Practice Questions and MCQs

Question 111: What is the most common complication of chickenpox?

A. Bacterial infection (Correct Answer)
B. Meningitis
C. Pneumonia
D. Nephritis

Explanation: **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.

Question 112: The characteristic rash of chickenpox exhibits which of the following distribution patterns?

A. Deep seated
B. Centripetal distribution (Correct Answer)
C. Monomorphic
D. Umbilicated

Explanation: **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.

Question 113: Which skin condition typically resolves on its own?

A. Basal cell carcinoma (BCC)
B. Psoriasis
C. Molluscum contagiosum (Correct Answer)
D. Eczema

Explanation: **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**.

Question 114: Which of the following conditions presents as umbilicated papules?

A. Plain warts
B. Chickenpox
C. Herpes genitalis
D. Molluscum contagiosum (Correct Answer)

Explanation: **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.

Question 115: The skin lesions of secondary syphilis include all of the following except?

A. Macules
B. Vesicles and bullae (Correct Answer)
C. Nodules
D. Papulosquamous lesions

Explanation: Secondary syphilis is often referred to as the **"Great Imitator"** because it can present with a wide variety of morphological patterns. However, a key diagnostic rule in adult syphilis is that it **does not produce vesicles or bullae.** ### Why "Vesicles and Bullae" is the correct answer: The hallmark of secondary syphilis is a systemic hematogenous spread of *Treponema pallidum*, resulting in a cellular immune response. This typically manifests as solid lesions (macules, papules, nodules). The formation of vesicles or bullae (blisters) requires a specific type of epidermal acantholysis or subepidermal fluid collection that is not part of the pathophysiology of adult syphilis. *Note:* The only exception is **Congenital Syphilis**, where "Pemphigus Syphiliticus" (bullous lesions) can occur on the palms and soles of neonates. ### Explanation of Incorrect Options: * **A. Macules:** The earliest sign is often a "Roseola Syphilitica," consisting of faint, erythematous, non-itchy macules on the trunk. * **C. Nodules:** While less common than papules, nodules can occur in late secondary syphilis or "Lues Maligna" (a severe form seen in immunocompromised/HIV patients). * **D. Papulosquamous lesions:** This is the most classic presentation. These are firm, reddish-brown ("raw ham" or "copper-colored") papules with a peripheral scale (Biett’s Collarette), frequently involving the **palms and soles**. ### High-Yield Clinical Pearls for NEET-PG: 1. **Palms and Soles:** Any papulosquamous rash involving the palms and soles should be considered secondary syphilis until proven otherwise. 2. **Condyloma Lata:** Highly infectious, moist, flat-topped hypertrophic papules found in intertriginous areas (axilla, perineum). 3. **Alopecia:** Characterized by a non-scarring, "moth-eaten" appearance. 4. **Mucous Patches:** Painless, silvery-gray ulcerations on the oral or genital mucosa. 5. **Ollendorff’s Sign:** Exquisite tenderness when a syphilis papule is touched with a probe.

Question 116: Dew drops on rose petal appearance is seen in infection with which of the following?

A. Varicella zoster virus (Correct Answer)
B. Herpes genitalis
C. Candida
D. T. rubrum

Explanation: **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.

Question 117: Eczema herpeticum is typically seen with which of the following viral infections?

A. Herpes Simplex Virus (HSV) (Correct Answer)
B. Epstein-Barr Virus (EBV)
C. Cytomegalovirus (CMV)
D. Varicella-Zoster Virus (VZV)

Explanation: **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.

Question 118: Satellite lesion with locally invasive property is seen in which of the following conditions?

A. Chronic hypertrophic candidiasis
B. Leukoplakia
C. Dental ulcers
D. Hemangioma (Correct Answer)

Explanation: **Explanation:** The correct answer is **Hemangioma**. In the context of dermatology and vascular anomalies, the term **"satellite lesions"** refers to smaller, peripheral vascular spots surrounding a primary lesion. While hemangiomas are benign vascular tumors, they can exhibit **locally invasive properties** by infiltrating deep into the dermis or subcutaneous tissues, occasionally involving underlying muscle or bone. This is particularly characteristic of certain subtypes like *tufted angiomas* or rapidly proliferating infantile hemangiomas, which can show satellite-like extensions during their growth phase. **Analysis of Incorrect Options:** * **Chronic Hypertrophic Candidiasis:** While Candidiasis is famous for "satellite pustules" or papules (especially in intertriginous areas), it is a superficial fungal infection. It is **not locally invasive** in the sense of destroying deep tissue structures. * **Leukoplakia:** This is a clinical term for a white patch or plaque. While it is a premalignant condition, the lesion itself is localized to the epithelium and does not present with satellite lesions unless it has already transformed into invasive squamous cell carcinoma. * **Dental Ulcers:** These are typically localized inflammatory or traumatic lesions (like aphthous ulcers) and do not exhibit satellite spread or invasive properties. **NEET-PG High-Yield Pearls:** * **Infantile Hemangioma:** The most common benign tumor of childhood. They are **GLUT-1 positive** (a key diagnostic marker). * **Phases:** They follow a predictable pattern of rapid proliferation (first year) followed by slow involution (over 5–10 years). * **Kasabach-Merritt Syndrome:** A life-threatening complication associated with specific vascular tumors (Tufted Angioma or Kaposiform Hemangioendothelioma), characterized by profound thrombocytopenia due to platelet sequestration. * **Treatment of Choice:** Oral **Propranolol** is now the first-line therapy for complicated infantile hemangiomas.

Question 119: A 40-year-old HIV-seropositive male presents with multiple, multicentric skin lesions and lymphadenitis. What is the most likely cause of this condition?

A. Human Herpesvirus 3 (HHV-3)
B. Human Herpesvirus 8 (HHV-8) (Correct Answer)
C. Human Herpesvirus 6 (HHV-6)
D. Human Herpesvirus 5 (HHV-5)

Explanation: **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.

Question 120: The pseudo-isomorphic phenomenon is seen in which of the following dermatological conditions?

A. Psoriasis
B. Lichen planus
C. Vitiligo
D. Molluscum contagiosum (Correct Answer)

Explanation: **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.

Practice by Chapter

Herpes Simplex Virus Infections

Practice Questions

Varicella-Zoster Virus Infections

Practice Questions

Human Papillomavirus Infections

Practice Questions

Molluscum Contagiosum

Practice Questions

Viral Exanthems

Practice Questions

Hand, Foot, and Mouth Disease

Practice Questions

Orf and Milker's Nodule

Practice Questions

Cytomegalovirus Cutaneous Manifestations

Practice Questions

Epstein-Barr Virus Manifestations

Practice Questions

Poxvirus Infections

Practice Questions

HIV-Related Dermatoses

Practice Questions

Viral Infections in Immunocompromised Hosts

Practice Questions

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