Viral Skin Infections Practice Questions

Q: A patient presented with multiple painful blisters on an erythematous base along a dermatome on the trunk, as shown in the image. What is the diagnosis? ![img-67.jpeg](img-67.jpeg)

Herpes zoster. ***Herpes zoster*** - This is the classic presentation of shingles, caused by the reactivation of the **Varicella-Zoster Virus (VZV)**, which presents as a painful, unilateral vesicular eruption in a restricted **dermatomal** distribution. - The virus remains dormant in the **dorsal root ganglia** after a primary chickenpox infection and reactivates later in life, often during periods of stress or immunosuppression. *Herpes simplex* - Herpes simplex virus (HSV) typically causes oral or genital lesions and does not usually follow a **dermatomal pattern**. - While HSV can cause skin infections, the distribution is localized to the site of inoculation rather than along a specific nerve root. *Molluscum contagiosum* - This condition is caused by a **poxvirus** and presents as flesh-colored, dome-shaped papules with central **umbilication**. - The lesions are not vesicular or painful and do not follow a dermatomal distribution. *Chicken pox* - This is the primary infection with **Varicella-Zoster Virus** and is characterized by a **generalized rash** with vesicles in different stages of healing (“dew drops on a rose petal”). - Unlike herpes zoster, the rash is widespread over the entire body and is not confined to a single dermatome.

Q: A patient presents with painful ulcer in the mouth and a past history of recurrent vesicular lesions in the genitalia. Bedside test findings are shown. What is the most appropriate drug for management?

Acyclovir. ***Correct: Acyclovir*** - The clinical history of recurrent painful oral and genital vesicular lesions, combined with the **Tzanck smear** finding of **multinucleated giant cells** (as shown in the image), is classic for **Herpes Simplex Virus (HSV)** infection. - **Acyclovir** is a guanosine analog antiviral drug that inhibits viral DNA polymerase, making it the first-line treatment for HSV and Varicella-Zoster Virus (VZV) infections. *Incorrect: Penicillin* - **Penicillin** is an antibiotic used to treat bacterial infections, most notably **syphilis**, which is caused by the spirochete *Treponema pallidum*. - Syphilis typically presents with a single, **painless chancre**, not recurrent painful vesicles, and penicillin has no efficacy against viral pathogens like HSV. *Incorrect: Ceftriaxone* - **Ceftriaxone** is a third-generation cephalosporin antibiotic, primarily used for bacterial infections such as **gonorrhea** and meningitis. - It is ineffective for treating viral infections, and the clinical presentation does not align with the purulent discharge characteristic of gonorrhea. *Incorrect: Azithromycin* - **Azithromycin** is a macrolide antibiotic effective against bacteria that can cause genital ulcers, such as **Haemophilus ducreyi** (causing **Chancroid**) and *Chlamydia trachomatis*. - While Chancroid causes painful ulcers, it does not typically present with a vesicular stage or the recurrent pattern seen in this case, nor would it show multinucleated giant cells on a smear.

Q: Identify the lesion shown in the image:

Herpes Zoster. ***Herpes Zoster (Shingles)*** - The image displays a characteristic **unilateral rash with vesicles and crusts** distributed along a **dermatome** on the child's face, specifically presenting as a pattern that follows the distribution of a **nerve root**, which is pathognomonic for **herpes zoster**. - This condition is caused by the **reactivation of the varicella-zoster virus (VZV)**, the same virus that causes chickenpox, remaining dormant in sensory ganglia. *Varicella (Chickenpox)* - Varicella typically presents as a **generalized rash** with lesions in various stages of development (macules, papules, vesicles, crusts) scattered across the entire body, not confined to a specific dermatome. - While caused by VZV, it is the **primary infection**, rather than reactivation, and does not exhibit a unilateral, dermatomal distribution. *Impetigo* - Impetigo is a **superficial bacterial skin infection** characterized by **honey-colored crusts** often preceded by small vesicles or bullae, but it does not typically follow a dermatomal pattern. - It usually occurs in areas of skin trauma or abrasions and is common around the nose and mouth. *Contact Dermatitis* - Contact dermatitis is an **inflammatory skin reaction** caused by contact with an allergen or irritant, resulting in redness, itching, and sometimes vesicles. - The distribution of contact dermatitis would typically correlate with the area of contact with the offending substance, not a specific nerve pathway.

Q: Identify the lesions given in the image:

Chickenpox. These options are generated based on the image only, as no options are provided in the input. ***Chickenpox*** - The image displays a rash characterized by **vesicles** and **crusted lesions** in various stages of healing, which is a hallmark of chickenpox (**varicella**). - The widespread distribution over the limbs and trunk, along with the polymorphic appearance of lesions, is typical for **Varicella-zoster virus infection**. *Measles* - Measles presents as a **maculopapular rash** that typically starts on the face and spreads downwards, often coalescing. - It does not typically involve the vesicular or crusted lesions seen in the image. *Rubella* - Rubella causes a **fine, pinkish-red rash** that is less prominent and generally fades more quickly than measles. - The lesions are usually discrete macules and do not progress to vesicles or crusts. *Erythema infectiosum* - This condition (also known as **Fifth Disease**) typically presents with a distinctive "slapped cheek" rash on the face, followed by a **lacy, reticular rash** on the trunk and limbs. - It does not produce vesicular lesions as depicted in the image.

Q: The following image shows:

Myrmecia. ***Myrmecia*** - The image shows a **plantar wart** (verruca plantaris) with a characteristic deep, solitary growth pattern and **central white core** visible after superficial paring, which is typical of **Myrmecia**, a type of plantar wart caused by HPV-1. - Myrmecia often appears as a **single, deep lesion** on the sole of the foot, distinguishable from mosaic warts which are flatter and multiple. *Filiform Warts* - **Filiform warts** are slender, finger-like projections found typically on the face, especially around the mouth and eyes, and are not seen on the sole of the foot as depicted. - They tend to be **flesh-colored** and project outwards rather than having a deep, endophytic growth pattern. *Epidermodysplasia verruciformis* - This is a rare, inherited genetic disorder characterized by **widespread, flat, wart-like lesions** and reddish-brown plaques, often resembling pityriasis versicolor, and is associated with a high risk of skin cancer. - The lesions seen in the image are localized and do not exhibit the broad, flat, widespread appearance typical of epidermodysplasia verruciformis. *Verruca vulgaris* - **Verruca vulgaris** (common warts) are typically common on the hands and fingers, presenting as raised, rough, **dome-shaped papules** with pinpoint black dots (thrombosed capillaries). - While they can occur anywhere, the morphology in the image, particularly the deep, endophitic growth with a central white core after paring, is more characteristic of a Myrmecia plantar wart than a typical verruca vulgaris.

Q: What is the causative agent for the lesion on penis shown below?

HPV. ***HPV*** - The image shows **condylomata acuminata** (genital warts), which are raised, exophytic, **cauliflower-like** lesions characteristic of **Human Papillomavirus** infection. - These **verrucous** growths on the penis are typically caused by **HPV types 6 and 11**, which are low-risk, non-oncogenic strains. *Treponema pallidum* - This organism causes **condylomata lata** in secondary syphilis, which are **flat, broad, moist** lesions, not the raised exophytic lesions shown. - **Condylomata lata** have a characteristic **flat-topped** appearance with a grayish base, distinctly different from the verrucous morphology seen here. *EBV* - **Epstein-Barr virus** is associated with **infectious mononucleosis** and certain malignancies like **Burkitt lymphoma** and nasopharyngeal carcinoma. - EBV does not cause **genital warts** or any proliferative penile lesions of this morphology. *KSHV* - **Kaposi's Sarcoma-associated Herpesvirus** (HHV-8) causes **Kaposi's sarcoma**, which presents as **purple, red, or brown** vascular lesions. - Kaposi's sarcoma lesions are typically **flat macules** progressing to **nodular tumors**, not cauliflower-like genital warts.

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

LDH levels. ***LDH levels*** - **Lactate dehydrogenase (LDH)** is a non-specific enzyme elevated in various conditions causing tissue damage or cellular turnover, but it is not a primary diagnostic tool for herpes zoster. - While systemic inflammation from a severe case of shingles might indirectly affect LDH, it is not used to confirm the diagnosis of this viral infection. *Direct fluorescent antibody* - **Direct fluorescent antibody (DFA)** testing from a blister scraping can rapidly detect varicella-zoster virus (VZV) antigens in cells. - This is a highly sensitive and specific method for confirming VZV infection, differentiating it from other blistering conditions. *Polymerase chain reaction* - **Polymerase chain reaction (PCR)** is a highly sensitive and specific method for detecting VZV DNA from vesicle fluid or crusts. - PCR can rapidly confirm the diagnosis of herpes zoster, especially in atypical presentations or immunocompromised patients. *Tzanck smear* - A **Tzanck smear** involves scraping the base of a blister and examining the cells microscopically for multinucleated giant cells and acantholytic cells. - While not specific for VZV (also seen in HSV infections), it indicates a herpes group viral infection and can be a rapid bedside diagnostic aid.

Q: Identify the lesion shown in the image:

Molluscum contagiosum. ***Molluscum contagiosum*** - The image shows **multiple, discrete, flesh-colored to pink, dome-shaped papules** with a characteristic **umbilicated center**. These features are classic for **molluscum contagiosum**. - This viral skin infection is caused by the **molluscum contagiosum virus (MCV)**, a Poxvirus, and is highly contagious, often affecting children or sexually active adults. *Herpes simplex* - Herpes simplex typically presents as **grouped vesicles on an erythematous base**, which later erode and crust. - The lesions seen in the image are **solid papules with central umbilication**, not fluid-filled vesicles or erosions. *Pityriasis rosea* - Pityriasis rosea characteristically begins with a **'herald patch'**, followed by a generalized eruption of smaller, oval, pinkish-red patches with fine scale arranged in a **'Christmas tree' pattern** on the trunk. - The depicted lesions are small, umbilicated papules, not scaly patches with a characteristic distribution. *Gianotti-Crosti syndrome* - Gianotti-Crosti syndrome, also known as papular acrodermatitis of childhood, presents with **monomorphic, flesh-colored to reddish-brown papules** or papulovesicles primarily on the **cheeks, buttocks, and extensor surfaces** of the extremities. - While papular, the lesions in the image have a distinct **umbilicated appearance** not typical for Gianotti-Crosti syndrome, and their distribution is not clearly suggestive of acrodermatitis.

Q: A patient after a trip to Bangkok developed fever and perioral vesicles. What is the diagnosis?

Herpes simplex. ***Herpes simplex*** - The combination of **fever** and **perioral vesicles** after a trip suggests a **viral infection**, with herpes simplex being a classic presentation. - Herpes simplex lesions typically appear as clusters of small, painful **vesicles** on an erythematous base, often affecting the lips and perioral area. *Impetigo* - Impetigo is a **bacterial skin infection** characterized by **honey-colored crusted lesions**, not clear vesicles. - It does not typically present with systemic symptoms like fever unless it is widespread or severe. *Molluscum contagiosum* - Molluscum contagiosum presents as **flesh-colored, dome-shaped papules** with a characteristic **umbilicated center**, not fluid-filled vesicles. - While it's a viral infection, systemic symptoms like fever are rare, and the lesion morphology is distinct. *Bullous pemphigoid* - Bullous pemphigoid is an **autoimmune blistering disease** characterized by large, tense bullae, usually in older adults. - It is not typically associated with acute onset of fever or travel history in this manner and lacks the clustered perioral vesicular appearance.

Q: A 28-year-old lady has asymptomatic dome shaped small lesions on the forehead for the last 2 months as shown in the image. She has a 2-year-old daughter with similar lesions. What is the causative agent? (AIIMS May 2016)

Poxvirus. ***Poxvirus*** - The description of **asymptomatic, dome-shaped small lesions** (suggesting **molluscum contagiosum**), especially with transmission from a child to a parent, is classic for **Molluscum contagiosum virus (MCV)**, which belongs to the **Poxviridae family**. - **Molluscum contagiosum** lesions can appear anywhere but are often seen on the face, neck, trunk, and extremities in children, and may be transmitted through close contact. *Papillomavirus* - **Papillomavirus** causes **warts**, which are typically **rough, verrucous** (cauliflower-like) lesions, not smooth, dome-shaped papules. - While warts can also be transmitted through close contact, their morphology is distinct from the lesions described. *Herpes virus* - **Herpes simplex virus (HSV)** causes **vesicular eruptions** (cold sores or fever blisters) that evolve into ulcers or crusts, often associated with pain, burning, or itching. - The lesions described as "asymptomatic dome-shaped" do not fit the typical presentation of herpes infections. *Coxsackie virus* - **Coxsackievirus** most commonly causes **hand-foot-and-mouth disease (HFMD)**, characterized by **fever**, **oral ulcers**, and a **rash of macules or vesicles** on the hands and feet. - This clinical picture is not consistent with the localized, dome-shaped papules on the forehead.

Question 1

A patient presented with multiple painful blisters on an erythematous base along a dermatome on the trunk, as shown in the image. What is the diagnosis? ![img-67.jpeg](img-67.jpeg)

Accepted Answer

Herpes zoster

Answer

Herpes simplex

Answer

Molluscum contagiosum

Answer

Chicken pox

Question 2

A patient presents with painful ulcer in the mouth and a past history of recurrent vesicular lesions in the genitalia. Bedside test findings are shown. What is the most appropriate drug for management?

Accepted Answer

Acyclovir

Answer

Ceftriaxone

Answer

Azithromycin

Answer

Penicillin

Question 3

Identify the lesion shown in the image:

Accepted Answer

Herpes Zoster

Answer

Varicella

Answer

Impetigo

Answer

Contact Dermatitis

Question 4

Identify the lesions given in the image:

Accepted Answer

Chickenpox

Answer

Measles

Answer

Rubella

Answer

Erythema infectiosum

Question 5

The following image shows:

Accepted Answer

Myrmecia

Answer

Filiform Warts

Answer

Epidermodysplasia verruciformis

Answer

Verruca vulgaris

Question 6

What is the causative agent for the lesion on penis shown below?

Accepted Answer

HPV

Answer

Treponema pallidum

Answer

EBV

Answer

KSHV

Question 7

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

Tzanck smear

Question 8

Identify the lesion shown in the image:

Accepted Answer

Molluscum contagiosum

Answer

Herpes simplex

Answer

Pityriasis rosea

Answer

Gianotti-Crosti syndrome

Question 9

A patient after a trip to Bangkok developed fever and perioral vesicles. What is the diagnosis?

Accepted Answer

Herpes simplex

Answer

Impetigo

Answer

Molluscum contagiosum

Answer

Bullous pemphigoid

Question 10

A 28-year-old lady has asymptomatic dome shaped small lesions on the forehead for the last 2 months as shown in the image. She has a 2-year-old daughter with similar lesions. What is the causative agent? (AIIMS May 2016)

Accepted Answer

Poxvirus

Answer

Papillomavirus

Answer

Herpes virus

Answer

Coxsackie virus

Viral Skin Infections — MCQs

Viral Skin Infections — MCQs

On this page

Practice by Chapter

Want unlimited practice?