NEET-PG 2015 - Dermatology Practice Questions

Q: Which of the following statements about actinic lichen planus is false?

Associated with severe pruritus. ***Associated with severe pruritus*** - While other forms of lichen planus, especially the typical cutaneous type, are often associated with **severe pruritus**, actinic lichen planus is typically characterized by **mild or absent pruritus**. - Its presentation is often more focused on pigmentary changes and papules in sun-exposed areas rather than intense itching. *Autoimmune etiology* - **Lichen planus**, including its actinic variant, is recognized as an **autoimmune disease**. - It involves a **T-cell-mediated immune response** against basal keratinocytes. *Violaceous brown papules* - Actinic lichen planus commonly presents with **violaceous, brown, or hyperpigmented papules and plaques**. - These lesions often exhibit a subtle **annular or reticulated pattern**. *Usually affects exposed areas of body* - As its name suggests ("actinic" referring to light), this variant of lichen planus preferentially affects **sun-exposed areas** such as the face, neck, and dorsal hands. - This distribution distinguishes it from classic lichen planus, which can occur anywhere but often affects the flexor surfaces of the wrists, ankles, and oral mucosa.

Q: All of the following are part of the treatment of scabies except?

Long term oral steroids. ***Long term oral steroids*** - **Long-term oral steroids** are generally avoided in scabies treatment as they can **suppress the immune system**, potentially worsening the infestation. - While steroids might offer temporary relief from itching, they do not address the underlying parasitic cause and can lead to various **side effects** with prolonged use. *Topical Permethrin* - **Topical permethrin** 5% cream is a **first-line treatment** for scabies, highly effective against the *Sarcoptes scabiei* mite. - It is typically applied to the entire body from the neck down, left on for 8-14 hours, and then washed off. *Oral ivermectin* - **Oral ivermectin** is an alternative treatment, particularly useful for **crusted scabies**, widespread infestations, or in cases where topical treatments are difficult to administer. - It acts by disrupting the nervous system of the mites, leading to their death. *Oral antihistamines* - **Oral antihistamines** are used to manage the **intense pruritus** (itching) associated with scabies. - They do not kill the mites but provide symptomatic relief, improving patient comfort.

Q: What do the Lines of Blaschko represent?

Patterns of cell migration. ***Patterns of cell migration*** - The **Lines of Blaschko** are invisible patterns in the skin reflecting the **movement and proliferation of cells** during embryonic development. - They become apparent in certain genetic conditions or mosaics when affected cells form streaks or swirls following these lines. *Patterns along lymphatics* - **Lymphatic patterns** refer to the distribution of the lymphatic system, which drains interstitial fluid and immune cells. - Skin conditions involving lymphatics often present as **lymphedema** or **lymphangitis**, which do not typically follow Blaschko's lines. *Patterns along blood vessels* - **Vascular patterns** describe the distribution of blood vessels in the skin, which can be affected in conditions like **livedo reticularis** or **vasculitis**. - These are distinct from Blaschko's lines, which are embryological in origin and not directly related to vascular anatomy. *Patterns along nerves* - **Nerve patterns** in the skin, such as **dermatomes**, correspond to the sensory innervation supplied by spinal nerves. - While some skin conditions can follow dermatomal distributions (e.g., **herpes zoster**), these are distinct from the embryological migration patterns represented by Blaschko's lines.

Q: Which of the following statements is true regarding pemphigus vulgaris?

It is an intraepidermal blistering disease.. ***It is an intraepidermal blistering disease.*** - **Pemphigus vulgaris** is characterized by the formation of blisters *within the epidermis* due to the loss of cell-to-cell adhesion between **keratinocytes**. - This **acantholysis** results from autoantibodies targeting **desmosomes**, specifically **desmoglein 1 and 3**. *It is a subepidermal blistering disease.* - This statement is incorrect as it describes conditions like **bullous pemphigoid** or **dermatitis herpetiformis**, where blisters form *below* the epidermis. - In pemphigus vulgaris, the separation occurs *above* the basement membrane within the epidermal layer. *It primarily affects the dermal-epidermal junction.* - This is characteristic of **bullous pemphigoid** or **epidermolysis bullosa acquisita**, where the primary pathology involves the separation at the interface between the dermis and epidermis. - Pemphigus vulgaris directly affects the adhesion *within* the epidermis itself. *Antibodies are formed against basement membrane proteins.* - This is characteristic of **bullous pemphigoid**, where autoantibodies target components of the **basement membrane zone**, such as **BP180** and **BP230**. - In pemphigus vulgaris, the autoantibodies target **desmogleins** on the surface of keratinocytes, not basement membrane proteins.

Q: Which of the following is characterized by a solitary painless ulcer on genitalia?

Syphilis. ***Syphilis*** - Primary syphilis typically presents as a **painless chancre** (ulcer) at the site of infection, usually the **genitalia**. - The painless nature is a key differentiating feature as it often goes unnoticed, allowing the disease to progress. *Genital herpes* - Characterized by multiple, small, often painful vesicles or ulcers that may coalesce [1]. - Lesions are typically tender or painful, unlike the **painless chancre** of syphilis [1]. *Traumatic injury* - While a traumatic injury can cause a solitary ulcer, it is usually painful and often associated with a clear history of trauma. - The ulcer's morphology and healing process may differ from a classic syphilitic chancre. *Chancroid* - Caused by *Haemophilus ducreyi*, chancroid presents as one or more painful, tender ulcers with ragged, undermined borders. - This is a significant differentiator from the **painless ulcer** seen in primary syphilis.

Q: Most common flexural site for atopic dermatitis -

Elbow crease. ***Elbow crease*** - The **antecubital fossa** (elbow crease) and **popliteal fossa** (knee crease) are the **two most characteristic flexural sites** for atopic dermatitis in children and adults. - Both sites are **equally common** and represent classic presentations of flexural eczema. - The constant rubbing, friction, and moisture retention in these areas contribute to skin irritation and the characteristic **lichenification** seen in atopic dermatitis. - In the context of this question asking for "most common," both antecubital and popliteal fossae are considered the primary flexural sites. *Popliteal fossa* - The **popliteal fossa** (behind the knee) is equally as common as the antecubital fossa and is a classic flexural site for atopic dermatitis. - It shares the same pathophysiological mechanisms and clinical presentation as the elbow crease. - Both antecubital and popliteal fossae are mentioned together in standard dermatology texts as the hallmark flexural sites. *Scalp* - While the scalp can be affected by atopic dermatitis, especially in **infants** (as **seborrheic dermatitis** or cradle cap), it is **not a flexural site**. - Scalp involvement typically presents as scaling and erythema, rather than the lichenified plaques characteristic of flexural eczema. *Trunk* - The trunk can be affected by atopic dermatitis with diffuse patches or widespread xerosis, but it is **not a flexural site**. - Flexural areas (skin folds) are the characteristic locations for atopic dermatitis in the flexural pattern.

Q: Which of the following statements about Bowen's disease is correct?

It is a form of squamous cell carcinoma in situ.. ***It is a form of squamous cell carcinoma in situ.*** - **Bowen's disease** is, by definition, **squamous cell carcinoma in situ (SCC in situ)**. - It is characterized by full-thickness epidermal atypia of keratinocytes **without invasion through the basement membrane**. - This statement is **definitional** and represents the fundamental nature of what Bowen's disease is, making it the **best answer** among the options. *Chronic sun exposure is a known risk factor.* - This statement is **medically accurate**. Chronic UV exposure is indeed a well-established risk factor for Bowen's disease. - However, this describes a **risk factor** rather than defining what the condition is. - Other risk factors include **arsenic exposure**, **ionizing radiation**, **immunosuppression**, and **HPV infection** (particularly in anogenital sites). - While true, this is not as fundamental as the definitional statement. *It is more common in fair-skinned individuals.* - This statement is also **medically accurate**. Bowen's disease occurs more frequently in fair-skinned individuals (Fitzpatrick skin types I-II). - Fair skin provides less melanin protection against UV damage, increasing susceptibility to various forms of skin cancer including Bowen's disease. - However, this describes **epidemiology** rather than defining the condition itself. *There is a link between HSV infection and Bowen's disease.* - This statement is **incorrect**. There is **no established association** between Herpes Simplex Virus (HSV) and Bowen's disease. - **Human Papillomavirus (HPV)**, particularly high-risk types 16 and 18, is associated with Bowen's disease, especially in anogenital locations. - This represents a common confusion between HSV and HPV.

Q: A girl about to marry has comedonal acne. Drug to treat such a case is:

Retinoids. ***Retinoids*** - **Topical retinoids** (e.g., tretinoin, adapalene) are the gold standard for comedonal acne as they normalize **follicular keratinization** and prevent microcomedone formation. - Being **Category C in pregnancy**, topical retinoids require **contraception counseling** for women of childbearing age but are still first-line treatment with proper precautions. *Benzoyl peroxide* - **Benzoyl peroxide** has mild comedolytic properties but is primarily effective for **inflammatory acne** due to its antimicrobial action against *Cutibacterium acnes*. - Less effective than retinoids for purely **comedonal acne** as it doesn't address the core pathology of abnormal keratinization. *Estrogen* - **Hormonal therapy** with estrogen-containing contraceptives reduces sebum production by suppressing androgens but takes **3-6 months** to show effects. - More suitable for **hormonal acne** with inflammatory lesions rather than purely comedonal acne, and not first-line for this presentation. *Topical antibiotic* - **Topical antibiotics** (clindamycin, erythromycin) target bacterial overgrowth and inflammation but have limited efficacy in **non-inflammatory comedonal acne**. - Risk of **bacterial resistance** when used alone, and they don't address the underlying hyperkeratinization that causes comedone formation.

Q: Maculae cerulea is seen in ?

Pediculosis pubis. ***Pediculosis pubis*** - **Maculae ceruleae** (blue spots) are **pathognomonic** for pubic louse (*Pthirus pubis*) infestation. - These characteristic **bluish-gray macules** are typically found on the trunk, thighs, and lower abdomen. - They result from the **anticoagulant in louse saliva** converting hemoglobin to biliverdin at feeding sites, causing localized hemorrhage and pigment deposition. - This is a **classic diagnostic feature** of pediculosis pubis. *Pediculosis hominis corporis* - Body louse infestation causes **pruritus** and **excoriations**, typically along clothing lines (waistband, collar). - **Maculae ceruleae** are not a feature of body louse infestation. *Pediculosis capitis* - Head lice infestation presents with **scalp pruritus**, **nits on hair shafts**, and excoriations. - **Maculae ceruleae** do not occur with head lice. *Scabies* - Caused by *Sarcoptes scabiei* mite burrowing in the stratum corneum. - Presents with **burrows**, **papules**, **vesicles**, and intense **nocturnal pruritus**. - **Maculae ceruleae** are NOT associated with scabies infestation.

Question 1

Which of the following statements about actinic lichen planus is false?

Accepted Answer

Associated with severe pruritus

Answer

Violaceous brown papules

Answer

Usually affects exposed areas of body

Answer

Autoimmune etiology

Question 2

All of the following are part of the treatment of scabies except?

Accepted Answer

Long term oral steroids

Answer

Topical Permethrin

Answer

Oral antihistamines

Answer

Oral ivermectin

Question 3

What do the Lines of Blaschko represent?

Accepted Answer

Patterns of cell migration

Answer

Patterns along lymphatics

Answer

Patterns along blood vessels

Answer

Patterns along nerves

Question 4

Which of the following statements is true regarding pemphigus vulgaris?

Accepted Answer

It is an intraepidermal blistering disease.

Answer

It primarily affects the dermal-epidermal junction.

Answer

It is a subepidermal blistering disease.

Answer

Antibodies are formed against basement membrane proteins.

Question 5

Which of the following is characterized by a solitary painless ulcer on genitalia?

Accepted Answer

Syphilis

Answer

Genital herpes

Answer

Traumatic injury

Answer

Chancroid

Question 6

Most common flexural site for atopic dermatitis -

Accepted Answer

Elbow crease

Answer

Popliteal fossa

Answer

Scalp

Answer

Trunk

Question 7

Which of the following statements about Bowen's disease is correct?

Accepted Answer

It is a form of squamous cell carcinoma in situ.

Answer

Chronic sun exposure is a known risk factor.

Answer

It is more common in fair-skinned individuals.

Answer

There is a link between HSV infection and Bowen's disease.

Question 8

A girl about to marry has comedonal acne. Drug to treat such a case is:

Accepted Answer

Retinoids

Answer

Topical antibiotic

Answer

Estrogen

Answer

Benzoyl peroxide

Question 9

Maculae cerulea is seen in ?

Accepted Answer

Pediculosis pubis

Answer

Pediculosis hominis corporis

Answer

Scabies

Answer

Pediculosis capitis

NEET-PG 2015 — Dermatology