NEET-PG 2015 - Dermatology Practice Questions

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: 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: In which of the following conditions is phototherapy, specifically ultraviolet light therapy, useful for treatment?

Psoriasis. ***Psoriasis*** - **Phototherapy** (narrowband UVB, broadband UVB, or PUVA) is a **well-established first-line treatment** for **moderate-to-severe psoriasis**. - It works by **suppressing overactive immune cells** in the skin, reducing inflammation and decreasing keratinocyte proliferation. - **Direct therapeutic effect** on active psoriatic lesions makes this the primary indication for phototherapy in dermatology. *Tinea corporis* - **Tinea corporis** is a **superficial fungal infection** (dermatophytosis) of the skin. - Requires **antifungal medications** (topical azoles or oral terbinafine/griseofulvin) for treatment. - **Phototherapy has no antifungal activity** and is not used for this condition. *Pemphigus* - **Pemphigus** is an **autoimmune blistering disease** with intraepidermal acantholysis. - Treatment requires **systemic immunosuppression** (corticosteroids, rituximab, azathioprine). - **Phototherapy is not indicated** and could potentially worsen the condition. *PMLE* - **Polymorphous light eruption (PMLE)** is a common **photosensitivity disorder**. - While **prophylactic photohardening** (gradual controlled UV exposure) can be used to build tolerance **before sun exposure season**, this is a **preventative desensitization strategy**, not treatment of active disease. - Unlike psoriasis, phototherapy does **not treat active PMLE lesions** and can trigger flares if not done properly. - The primary approach for active PMLE is **sun avoidance, sun protection, and topical corticosteroids**.

Q: Acanthosis nigricans is characterized by all of the following except?

Histologically there is hypermelanosis. ***Histologically there is hypermelanosis*** - This statement is **FALSE** and is the correct answer to this "EXCEPT" question - The characteristic dark appearance of acanthosis nigricans is **NOT due to increased melanin** (hypermelanosis) - Histologically, the key features are **hyperkeratosis, papillomatosis, and mild acanthosis** - There is typically **minimal or no increase in melanocytes or melanin pigment** - The hyperpigmentation seen clinically is an optical effect from the thickened, hyperkeratotic epidermis *May be a sign of internal malignancy* - This statement is **true**; acanthosis nigricans can be a paraneoplastic syndrome associated with internal malignancies - **Malignant acanthosis nigricans** is particularly associated with **gastrointestinal adenocarcinomas** (especially gastric) - This form typically has sudden onset, rapid progression, and more widespread involvement *Common in obese people* - This statement is **true**; acanthosis nigricans is frequently associated with **insulin resistance** - Commonly seen in individuals with **obesity, type 2 diabetes, and metabolic syndrome** - This benign form typically affects flexural areas (neck, axillae, groin) *Associated with thick skin with hyperpigmentation* - This statement is **true**; these are the hallmark clinical features of acanthosis nigricans - Presents as **velvety thickening** and **dark brown to black hyperpigmentation** - Typically affects intertriginous areas and skin folds

Q: Which of the following organisms has a role to play in Seborrheic dermatitis?

Pityrosporum ovale. ***Pityrosporum ovale*** - **Pityrosporum ovale**, now known as **Malassezia furfur**, is a lipophilic yeast that colonizes the skin and plays a significant role in the pathogenesis of **seborrheic dermatitis**. - Its presence is commonly associated with the inflammatory response seen in seborrheic dermatitis, though the exact mechanism is not fully understood. *Candida albicans* - **Candida albicans** is a common cause of **mucocutaneous candidiasis** and **intertrigo**, but it is not directly implicated in the etiology of seborrheic dermatitis. - While it can cause skin infections, its typical presentation involves erythematous, macerated rashes with satellite lesions in skin folds. *Propionibacterium* - **Propionibacterium acnes**, now known as **Cutibacterium acnes**, is primarily associated with the pathogenesis of **acne vulgaris**. - It plays a role in the inflammation and comedone formation characteristic of acne, not the scaling and erythema of seborrheic dermatitis. *None of the above* - This option is incorrect because **Pityrosporum ovale (Malassezia furfur)** is a well-recognized organism involved in seborrheic dermatitis. - The other organisms listed are associated with different dermatological conditions.

Q: Pruritus is a feature of which of the following conditions?

Bullous pemphigoid. ***Bullous pemphigoid*** - **Pruritus**, often severe, is a common and early symptom of bullous pemphigoid, often preceding the appearance of skin lesions. - The disease involves autoantibodies against **hemidesmosomal proteins** (BPAG1, BPAG2), leading to subepidermal blister formation. *Pemphigus foliaceous* - This condition is characterized by **superficial blistering** and erosions, but **pruritus is typically mild or absent**. - Blisters form in the **granular layer of the epidermis** due to autoantibodies against desmoglein 1. *Pemphigus vulgaris* - Patients with pemphigus vulgaris present with **flaccid blisters and erosions**, mainly affecting the skin and mucous membranes, but **pruritus is not a prominent feature**. - The disease involves intraepidermal blistering caused by autoantibodies targeting **desmoglein 3 (and sometimes desmoglein 1)**. *None of the options* - This option is incorrect, as **pruritus is a characteristic symptom of bullous pemphigoid**.

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.

Q: Which of the following is true about keratinocytes?

Ectoderm derived cell. ***Ectoderm derived cell*** - Keratinocytes originate from the **ectoderm**, one of the three primary germ layers in embryonic development, which gives rise to the epidermis. - This ectodermal origin is fundamental to their role in forming the protective outer layer of the skin. *Differentiate in basal layer* - Keratinocytes in the **basal layer (stratum basale)** are primarily responsible for **proliferation** (cell division) rather than differentiation. - **Differentiation** into flattened, keratin-filled cells occurs as they migrate upwards through the epidermal layers. *Mature in basal layer* - Maturation, which involves the accumulation of **keratin** and the loss of organelles, primarily occurs in the **upper layers** of the epidermis (stratum spinosum, granulosum, corneum). - The basal layer is where new cells are generated, not where they reach their mature, fully keratinized state. *Present only in basal layer* - While keratinocytes originate in the basal layer, they are the **predominant cell type throughout all layers of the epidermis**. - They represent approximately 90% of epidermal cells and are found from the stratum basale to the stratum corneum.

Question 1

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 2

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 3

In which of the following conditions is phototherapy, specifically ultraviolet light therapy, useful for treatment?

Accepted Answer

Psoriasis

Answer

Tinea corporis

Answer

Pemphigus

Answer

PMLE

Question 4

Acanthosis nigricans is characterized by all of the following except?

Accepted Answer

Histologically there is hypermelanosis

Answer

Associated with thick skin with hyperpigmentation

Answer

May be a sign of internal malignancy

Answer

Common in obese people

Question 5

Which of the following organisms has a role to play in Seborrheic dermatitis?

Accepted Answer

Pityrosporum ovale

Answer

Propionibacterium

Answer

Candida albicans

Answer

None of the above

Question 6

Pruritus is a feature of which of the following conditions?

Accepted Answer

Bullous pemphigoid

Answer

Pemphigus foliaceous

Answer

Pemphigus vulgaris

Answer

None of the options

Question 7

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 8

Maculae cerulea is seen in ?

Accepted Answer

Pediculosis pubis

Answer

Pediculosis hominis corporis

Answer

Scabies

Answer

Pediculosis capitis

Question 9

Which of the following is true about keratinocytes?

Accepted Answer

Ectoderm derived cell

Answer

Differentiate in basal layer

Answer

Mature in basal layer

Answer

Present only in basal layer

NEET-PG 2015 — Dermatology