Palmoplantar Psoriasis — MCQs

10 questions

What is the primary condition for which calcitriol is used as a treatment?

All are nail changes seen in cases of psoriasis except:

A patient presents with orange-hued skin lesions and hyperkeratotic palms and soles. A biopsy shows alternating parakeratosis and orthokeratosis. What is the most likely diagnosis?

The following is an important feature of psoriasis:

PUVA therapy is used in all except:

Skin biopsy shows psoriasiform hyperplasia with neutrophilic microabscesses in stratum corneum. Most likely diagnosis?

A patient with psoriasis who was started on systemic steroids develops generalized pustules all over the body after stopping treatment. What is the most likely cause?

Auspitz sign is seen in?

All are true about psoriasis except –

Q10

Acrodermatitis continua of Hallopeau is due to which of the following?

Palmoplantar Psoriasis Indian Medical PG Practice Questions and MCQs

Question 1: What is the primary condition for which calcitriol is used as a treatment?

A. Pemphigus
B. Secondary hyperparathyroidism (Correct Answer)
C. Lichen planus
D. Leprosy

Explanation: Secondary hyperparathyroidism - Calcitriol is the active form of vitamin D (1,25-dihydroxyvitamin D₃), and it is crucial for regulating calcium and phosphate levels in the body [1]. - In secondary hyperparathyroidism, often seen in chronic kidney disease (CKD), the kidneys cannot convert vitamin D to its active form, leading to hypocalcemia and increased PTH secretion [1], [2]. - Calcitriol supplementation helps to increase calcium absorption from the gut and suppress the release of parathyroid hormone (PTH), thereby treating the underlying cause of secondary hyperparathyroidism [1], [2]. - This is the primary therapeutic indication for calcitriol in clinical practice. Lichen planus - This is a chronic inflammatory condition affecting the skin, hair, nails, and mucous membranes - Typically treated with corticosteroids or other immunosuppressants - Calcitriol has no primary role in the treatment of lichen planus; its therapeutic applications are predominantly related to calcium and bone metabolism Pemphigus - Pemphigus is a group of rare autoimmune blistering diseases that affect the skin and mucous membranes - Primary treatment involves immunosuppressants like corticosteroids, often in high doses - Calcitriol is not indicated for the treatment of pemphigus, as its mechanism of action is unrelated to the autoimmune processes characteristic of this disease Leprosy - Leprosy is a chronic infectious disease caused by the bacterium Mycobacterium leprae - Treated with multi-drug therapy (MDT), which includes antibiotics like rifampicin, dapsone, and clofazimine - Calcitriol is not an antibiotic and therefore has no role in treating the bacterial infection responsible for leprosy

Question 2: All are nail changes seen in cases of psoriasis except:

A. Subungual hyperkeratosis
B. Oil drop sign
C. Mees lines (Correct Answer)
D. Pitting

Explanation: ***Mees lines*** - **Mees lines** (or Aldrich-Mees lines) are **transverse white bands** that appear in the nail plate. - They are typically associated with **heavy metal poisoning** (e.g., arsenic), chemotherapy, or systemic illnesses, not psoriasis. *Subungual hyperkeratosis* - This is a common finding in **psoriasis**, characterized by the **thickening of the nail bed** due to excessive keratin production. - It leads to lifting of the nail plate from the nail bed. *Oil drop sign* - The **oil drop sign** (or salmon patch) is a classic psoriatic nail change, presenting as a **translucent, yellowish-red discoloration** under the nail plate. - It is due to psoriasis of the nail bed. *Pitting* - **Nail pitting** refers to the presence of **small depressions or pits** on the nail surface. - It results from defective keratinization of the nail matrix and is a characteristic sign of nail psoriasis.

Question 3: A patient presents with orange-hued skin lesions and hyperkeratotic palms and soles. A biopsy shows alternating parakeratosis and orthokeratosis. What is the most likely diagnosis?

A. Pityriasis rubra pilaris (Correct Answer)
B. Follicular psoriasis
C. Keratosis follicularis
D. Ichthyosis vulgaris

Explanation: ***Pityriasis rubra pilaris*** - This condition classically presents with **salmon-colored to orange-hued plaques** and **hyperkeratotic palms and soles**. - Histologically, Pityriasis rubra pilaris is characterized by **alternating parakeratosis and orthokeratosis** in vertical and horizontal directions ("checkerboard" pattern). *Follicular psoriasis* - While psoriasis can present with hyperkeratosis and scales, **follicular psoriasis** specifically involves the hair follicles, seen as follicular papules and pustules. - The classic alternating parakeratosis and orthokeratosis is more indicative of PRP than of follicular psoriasis, which typically shows more uniform parakeratosis. *Keratosis follicularis* - Also known as Darier disease, this condition presents with **greasy, crusted, foul-smelling papules** on seborrheic areas. - Histopathology reveals characteristic **dyskeratosis** with acantholytic cells (corps ronds and grains), which is different from the described alternating parakeratosis and orthokeratosis. *Ichthyosis vulgaris* - This is a genetic disorder characterized by **dry, scaly skin** due to impaired epidermal barrier function, often worse in winter. - Histopathology typically shows a **diminished or absent granular layer** and compact orthokeratosis without parakeratosis, differing from the biopsy findings.

Question 4: The following is an important feature of psoriasis:

A. Erythematous macules
B. Crusting
C. Silvery Scaling (Correct Answer)
D. Coarse bleeding

Explanation: ***Silvery Scaling*** - **Silvery scaling** is a hallmark clinical feature of **psoriasis**, resulting from the rapid turnover of skin cells. - These scales often appear on **erythematous plaques** and can be easily scraped off, sometimes revealing pinpoint bleeding underneath (**Auspitz sign**). *Erythematous macules* - While psoriasis does involve **erythema** (redness), the primary lesions are typically **plaques**, not macules (flat, discolored spots). - Macules are seen in other dermatological conditions such as drug eruptions or early viral exanthems, but not as the definitive feature of psoriasis. *Crusting* - **Crusting** is a feature of conditions involving exudation and drying of serum, blood, or pus, such as **impetigo** or **eczema** with secondary infection. - It is not a characteristic primary lesion of psoriasis, although secondary infection of psoriatic plaques could theoretically lead to crusting. *Coarse bleeding* - **Coarse bleeding** is not a primary feature of psoriasis; however, when psoriatic scales are removed, pinpoint bleeding known as the **Auspitz sign** can occur. - This is distinct from frank, coarse bleeding and is a diagnostic clue rather than a characteristic lesion in itself.

Question 5: PUVA therapy is used in all except:

A. Psoriasis
B. Vitiligo
C. Mycosis fungoides
D. Melasma (Correct Answer)

Explanation: ***Melasma*** - **PUVA (Psoralen plus UVA) therapy** is contraindicated in melasma due to its potential to worsen hyperpigmentation and cause paradoxical darkening. - Melasma is best managed with topical agents like **hydroquinone**, **tretinoin**, and chemical peels, along with strict **sun protection**. *Psoriasis* - **PUVA therapy** is a well-established and effective treatment for moderate to severe psoriasis, especially for patients with widespread plaques. - It works by inhibiting DNA synthesis and cell proliferation in rapidly dividing keratinocytes, leading to a reduction in psoriatic lesions. *Vitiligo* - **PUVA therapy** is a common treatment for vitiligo, stimulating melanocyte activity and promoting repigmentation in affected areas. - Psoralen sensitizes melanocytes to UVA light, which then encourages melanin production. *Mycosis fungoides* - In its early stages, **mycosis fungoides**, a cutaneous T-cell lymphoma, can be effectively treated with **PUVA therapy**. - PUVA induces apoptosis of malignant T-cells in the skin, leading to remission of skin lesions.

Question 6: Skin biopsy shows psoriasiform hyperplasia with neutrophilic microabscesses in stratum corneum. Most likely diagnosis?

A. Psoriasis (Correct Answer)
B. Seborrheic dermatitis
C. Pityriasis rosea
D. Lichen planus

Explanation: ***Psoriasis*** - **Psoriasiform hyperplasia**, characterized by regular epidermal acanthosis and elongated rete ridges, is a classic histological feature of psoriasis. - The presence of **neutrophilic microabscesses (Munro microabscesses)** in the stratum corneum is a pathognomonic finding for psoriasis. *Seborrheic dermatitis* - Histologically, seborrheic dermatitis typically shows **irregular acanthosis** with parakeratosis and a **perivascular lymphocytic infiltrate**, but not regular psoriasiform hyperplasia or Munro microabscesses. - There may be *spongiosis* and neutrophils in the stratum corneum, but not the distinct microabscesses seen in psoriasis. *Pityriasis rosea* - Pityriasis rosea histology often reveals **focal parakeratosis**, **spongiosis**, and a **perivascular lymphocytic infiltrate** with extravasated red blood cells. - It does not demonstrate the characteristic regular psoriasiform hyperplasia or neutrophilic microabscesses of psoriasis. *Lichen planus* - Lichen planus is characterized by a **"sawtooth" rete ridge pattern**, a **band-like lymphocytic infiltrate** at the dermo-epidermal junction, and **colloid bodies (Civatte bodies)**. - It does not exhibit psoriasiform hyperplasia or neutrophilic microabscesses in the stratum corneum.

Question 7: A patient with psoriasis who was started on systemic steroids develops generalized pustules all over the body after stopping treatment. What is the most likely cause?

A. Bacterial infection
B. Septicemia
C. Pustular psoriasis due to steroid withdrawal (Correct Answer)
D. Drug-induced pustular psoriasis

Explanation: ***Pustular psoriasis due to steroid withdrawal*** - **Systemic steroid withdrawal** can precipitate a severe flare of psoriasis, often leading to generalized **pustular psoriasis**. - This is a well-known phenomenon where the suppression of the immune system by steroids is abruptly removed, causing a rebound inflammatory response. *Drug-induced pustular psoriasis* - While certain drugs can induce pustular psoriasis, the scenario specifically highlights the **cessation of systemic steroids** as the trigger. - This option doesn't pinpoint the direct causal effect of stopping the medication. *Bacterial infection* - Although pustules can be associated with bacterial infections, the **generalized nature** and history of **steroid withdrawal** in a patient with psoriasis make an infectious cause less likely as the primary trigger. - A bacterial infection would typically present with signs of local infection (e.g., warmth, tenderness, fever) alongside the pustules, which are not exclusively mentioned here. *Septicemia* - **Septicemia** is a severe bloodstream infection and would present with systemic signs of illness such as high fever, chills, hypotension, and organ dysfunction, which are not described. - While pustules can sometimes occur in severe infections, the clinical context strongly points to a dermatological reaction to medication changes, not a systemic infection.

Question 8: Auspitz sign is seen in?

A. Psoriasis (Correct Answer)
B. Vitiligo
C. Contact dermatitis
D. Lichen Planus

Explanation: ***Psoriasis*** - Auspitz sign refers to the appearance of **pinpoint bleeding** after the removal of psoriatic scales. - This phenomenon is caused by the thinning of the **epidermis** over the dermal papillae, making the superficial blood vessels more prone to rupture. *Vitiligo* - Vitiligo is characterized by **patches of depigmentation** due to the destruction of melanocytes. - It does not involve scaling or bleeding upon scratching. *Contact dermatitis* - Contact dermatitis is an **inflammatory skin reaction** caused by contact with an allergen or irritant, presenting as redness, itching, and sometimes vesicles. - While scratching can cause bleeding, it does not typically produce the specific **pinpoint bleeding** pattern seen with Auspitz sign. *Lichen Planus* - Lichen planus is an **inflammatory condition** affecting the skin, hair, nails, and mucous membranes, characterized by **pruritic, polygonal, purple papules**. - It does not present with scaling that reveals pinpoint bleeding when removed.

Question 9: All are true about psoriasis except –

A. Auspitz sign positive
B. Parakeratosis & acanthosis
C. Joint involvement in 5–10% (Correct Answer)
D. Pitting of nails
E. Koebner phenomenon

Explanation: ***Joint involvement in 5–10%*** - While **psoriasis** is a skin condition, it can involve the joints in about **30% of patients**, leading to **psoriatic arthritis**. - Therefore, stating that joint involvement occurs in only **5-10%** is incorrect, as the percentage is significantly higher. - This is the **FALSE statement** in this EXCEPT question. *Auspitz sign positive* - The **Auspitz sign** (pinpoint bleeding when scales are removed) is a classic feature of psoriasis. - It occurs due to the proximity of dilated capillaries to the thinned suprapapillary epidermis. - This is a **TRUE statement**. *Parakeratosis & acanthosis* - **Parakeratosis** (retention of nuclei in the stratum corneum) and **acanthosis** (epidermal hyperplasia) are classic histopathological features of psoriasis. - These features reflect the **rapid cell turnover** and **thickening of the epidermis** characteristic of psoriatic plaques. - This is a **TRUE statement**. *Pitting of nails* - **Nail pitting** is a common manifestation of psoriasis, affecting up to **50% of patients** with chronic plaque psoriasis and **80% of patients with psoriatic arthritis**. - Other nail changes include **onycholysis**, **subungual hyperkeratosis**, and discoloration. - This is a **TRUE statement**. *Koebner phenomenon* - **Koebner phenomenon** (isomorphic response) is the development of psoriatic lesions at sites of trauma or injury. - This is seen in approximately **25% of patients** with psoriasis and is a well-recognized clinical feature. - This is a **TRUE statement**.

Question 10: Acrodermatitis continua of Hallopeau is due to which of the following?

A. Zinc toxicity
B. Zinc deficiency
C. Collodion baby
D. Pustular psoriasis (Correct Answer)

Explanation: ***Pustular psoriasis*** - **Acrodermatitis continua of Hallopeau** is considered a severe, chronic, and localized variant of **pustular psoriasis** that primarily affects the distal extremities, particularly the nail beds and fingertips. - It involves recurrent outbreaks of **sterile pustules** that can lead to onychodystrophy, anonychia, and bone resorption. *Zinc toxicity* - **Zinc toxicity** can cause symptoms such as nausea, vomiting, abdominal pain, and copper deficiency, but it is not linked to acrodermatitis continua of Hallopeau. - Dermatological manifestations of zinc toxicity are generally not pustular or associated with nail and digit changes seen in this condition. *Zinc deficiency* - **Zinc deficiency** can lead to acrodermatitis enteropathica, a condition characterized by periorificial and acral dermatitis, alopecia, and diarrhea. - While it involves skin involvement in similar areas, the primary lesions are **eczematous and psoriasiform**, not typically sterile pustules as seen in acrodermatitis continua. *Collodion baby* - **Collodion baby** refers to a newborn covered by a taut, shiny membrane that resembles plastic wrap, typically associated with congenital ichthyoses. - It is a specific neonatal presentation of a skin barrier defect and is not related to acrodermatitis continua of Hallopeau or pustular skin conditions.

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