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?

PUVA therapy is used in all except:

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

Auspitz sign is seen in?

All are true about psoriasis except –

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

The important feature of psoriasis is –

Q10

A patient with psoriasis was started on systemic steroids. After stopping treatment, the patient developed generalized pustules all over the body. The cause is most likely to be:

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: 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 5: 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 6: 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 7: 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 8: 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.

Question 9: The important feature of psoriasis is –

A. Oozing
B. Crusting
C. Scaling (Correct Answer)
D. Erythema

Explanation: ***Scaling*** - Psoriasis is characterized by **erythematous plaques** covered with **silvery-white scales**, which is the **hallmark and most distinguishing feature** of the condition. - These scales result from **accelerated epidermal turnover** (3-4 days vs. normal 28 days) causing **hyperproliferation and abnormal differentiation of keratinocytes**. - The **Auspitz sign** (pinpoint bleeding upon scale removal) is a classic diagnostic feature. - Scaling is what differentiates psoriasis from other erythematous conditions. *Oozing* - **Oozing**, also known as weeping, is typically associated with acute inflammatory skin conditions, such as **acute eczema** or **bacterial infections**. - It indicates the presence of serous exudate from the skin, which is not a primary feature of psoriasis. *Crusting* - **Crusting** involves dried serum, blood, or pus on the skin surface and is commonly seen in conditions like **impetigo** or healing wounds. - While secondary infections can occur in psoriatic lesions, crusting itself is not a defining characteristic. *Erythema* - **Erythema**, or redness, is indeed present in psoriatic plaques, but it is not the *most important distinguishing feature*. - Many inflammatory skin conditions cause erythema, so it is a non-specific finding without the presence of prominent scaling.

Question 10: A patient with psoriasis was started on systemic steroids. After stopping treatment, the patient developed generalized pustules all over the body. The cause is most likely to be:

A. Drug induced reaction
B. Septicemia
C. Pustular psoriasis (Correct Answer)
D. Bacterial infections

Explanation: ***Pustular psoriasis*** - The sudden withdrawal of **systemic corticosteroids** in a patient with psoriasis can trigger a severe flare-up, specifically **generalized pustular psoriasis** (GPP), characterized by widespread sterile pustules. - GPP is a distinct, severe form of psoriasis that can be precipitated by various factors, including drug withdrawal. *Drug induced reaction* - While steroids themselves can have side effects, the development of **generalized pustules** shortly after stopping treatment in a known psoriasis patient points more specifically to a paradoxical worsening of their underlying disease rather than a general drug reaction. - Drug-induced reactions are typically directly related to the drug's properties or an allergic response, whereas this scenario describes an exacerbation of the existing condition due to treatment cessation. *Septicemia* - Septicemia, or **sepsis**, would present with signs of systemic infection such as **fever, chills, hypotension, and organ dysfunction**, which are not explicitly mentioned as the primary cause of the pustules. - While severe GPP can lead to systemic symptoms and potentially secondary infections, the initial development of pustules post-steroid withdrawal is a primary dermatological event, not directly caused by septicemia. *Bacterial infections* - **Bacterial infections** would typically manifest with purulent pustules, often with signs of inflammation, pain, and potentially fever. These pustules would contain bacteria upon Gram stain and culture. - The pustules in **pustular psoriasis** are typically sterile, meaning they do not contain bacteria, and their appearance is a manifestation of the underlying autoimmune inflammatory process exacerbated by steroid withdrawal.

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