Psoriasis — MCQs

Psoriasis Indian Medical PG Practice Questions and MCQs

Question 101: PUVA therapy is used in:

A. Melasma
B. Lichen planus
C. Psoriasis (Correct Answer)
D. Freckles

Explanation: ***Psoriasis*** - **PUVA (Psoralen plus ultraviolet A)** therapy is a well-established and effective treatment for **moderate-to-severe psoriasis**. - Psoralen is a photosensitizing agent that, when activated by UVA light, inhibits **DNA synthesis** and reduces cell proliferation in the affected skin. - PUVA is considered a **gold standard phototherapy** for psoriasis, particularly for extensive plaque psoriasis and generalized disease. *Melasma* - Melasma is a **hyperpigmentary disorder** characterized by dark patches on the face. - While some light-based therapies are used, **topical agents** like hydroquinone and chemical peels are the primary treatments, and PUVA is not typically indicated due to the risk of worsening hyperpigmentation. *Lichen planus* - Lichen planus is an **inflammatory skin condition** that can be treated with phototherapy including **PUVA**, particularly for oral lichen planus and widespread cutaneous disease. - However, **narrowband UVB** is generally preferred as first-line phototherapy due to fewer side effects. - While PUVA has a role in lichen planus, psoriasis remains the **primary and most established indication** for this therapy. *Freckles* - Freckles are **benign pigmented macules** and do not require medical treatment. - Protection from **UV exposure** and cosmetic treatments like laser therapy for aesthetic reasons are sometimes used, but PUVA is entirely inappropriate and would cause harm.

Question 102: In psoriasis, the following are seen except:

A. Skin involvement
B. CNS involvement (Correct Answer)
C. Nail changes
D. Arthritis

Explanation: ***CNS involvement*** - Psoriasis is primarily a **skin disorder** with systemic manifestations but typically does **not directly involve the central nervous system**. - While patients with psoriasis may experience symptoms like depression or anxiety, these are generally considered **comorbid conditions** rather than direct manifestations of psoriatic pathology in the CNS. *Skin involvement* - **Plaque psoriasis**, the most common form, is characterized by well-demarcated, erythematous plaques with silvery scales. - Psoriasis directly affects the skin, leading to rapid **keratinocyte proliferation** and inflammation. *Nail changes* - **Onycholysis (separation of the nail from the nail bed)**, **pitting**, and **oil spots** (yellow-brown discolorations under the nail) are common in psoriasis. - These nail changes can occur with or without concurrent skin involvement. *Arthritis* - **Psoriatic arthritis (PsA)** is a chronic inflammatory arthritis associated with psoriasis, affecting up to 30% of patients. - It can involve peripheral joints, the **axial skeleton**, and entheses, often presenting with symptoms like stiffness and pain.

Question 103: In Erythrodermic psoriasis, _____ or more of body surface area is involved

A. 90% (Correct Answer)
B. 85%
C. 95%
D. 80%

Explanation: ***90%*** - Erythrodermic psoriasis is defined by the involvement of **90% or more of the total body surface area** with erythema and scaling. - This extensive skin involvement leads to significant systemic symptoms and is considered a **medical emergency**. - It represents the most severe form of psoriasis with near-complete body involvement. *85%* - While representing extensive involvement, **85%** does not meet the diagnostic threshold for erythrodermic psoriasis. - The definition specifically requires **≥90%** body surface area involvement. *95%* - Although **95%** body surface area involvement would certainly qualify as erythrodermic psoriasis, it exceeds the minimum diagnostic threshold. - The defining cutoff is **90% or more**, not 95%. *80%* - Involvement of **80%** of the body surface area, while extensive, does not meet the criteria for erythrodermic psoriasis. - This would typically be classified as **severe plaque psoriasis** rather than erythrodermic form.

Question 104: 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 105: A 30-year-old male presented with silvery scales on elbow and knee, that bleed on removal. The probable diagnosis is:

A. Secondary syphilis
B. Psoriasis (Correct Answer)
C. Pityriasis
D. Seborrhoeic dermatitis

Explanation: ***Psoriasis*** - The presence of **silvery scales** on the elbows and knees, which **bleed upon removal** (Auspitz sign), is a classic presentation of **plaque psoriasis**. - Psoriasis is a chronic inflammatory skin condition characterized by **accelerated epidermal turnover**. *Secondary syphilis* - Secondary syphilis typically presents with a **generalized maculopapular rash**, which can affect the palms and soles, but it does not usually feature silvery scales or the Auspitz sign. - Other common symptoms of secondary syphilis include **fever, lymphadenopathy, and condyloma lata**. *Pityriasis* - **Pityriasis rosea** is characterized by an oval, fawn-colored, scaly rash, often preceded by a **herald patch**, and usually resolves spontaneously. It does not typically present with silvery scales or bleeding on removal. - **Pityriasis versicolor** is caused by yeast and presents as hypopigmented or hyperpigmented macules with fine scales, commonly on the trunk, not silvery scales on elbows and knees. *Seborrhoeic dermatitis* - Seborrhoeic dermatitis involves greasy, yellowish scales on red skin, typically affecting areas rich in sebaceous glands like the scalp, face (nasolabial folds, eyebrows), and chest. - It does not present with silvery scales or the Auspitz sign, which are specific to psoriasis.

Question 106: Psoriasis is exacerbated by -

A. Beta-blockers
B. Lithium
C. Antimalarials
D. All of the options (Correct Answer)

Explanation: ***All of the above*** - **Beta-blockers**, **lithium**, and **antimalarial drugs** are well-established medications that can exacerbate or trigger psoriasis flares. - Patients with psoriasis require careful monitoring when these medications are prescribed, with consideration of alternative treatments when feasible. ***Beta-blockers*** - **Non-selective beta-blockers** (particularly propranolol) can worsen existing psoriasis or induce new-onset disease. - The mechanism likely involves alterations in **T-cell function** and **epidermal proliferation**. - Risk is higher with non-selective agents compared to cardioselective beta-blockers. ***Lithium*** - **Lithium**, used for bipolar disorder, is a frequent and well-documented psoriasis trigger. - Can induce or worsen various forms including **plaque psoriasis**, **pustular psoriasis**, and **erythrodermic psoriasis**. - Exacerbations typically occur within weeks to months of initiation. ***Antimalarials*** - **Chloroquine** and **hydroxychloroquine** can precipitate severe psoriasis flares. - Particularly associated with **erythrodermic** and **generalized pustular psoriasis**. - Mechanism involves **immune cell activation** and amplification of inflammatory pathways.

Question 107: Koebner's phenomenon is characteristic of –

A. Psoriasis (Correct Answer)
B. Lupus vulgaris
C. Pemphigus vulgaris
D. Pityriasis rosea

Explanation: ***Psoriasis*** - **Koebner's phenomenon**, or isomorphic response, refers to the development of new lesions at sites of **skin trauma** (e.g., cuts, scratches, burns, or friction). - This phenomenon is **most characteristically associated with psoriasis** and is considered a distinctive clinical feature that helps in diagnosis. - While Koebner's phenomenon can occur in other dermatological conditions (such as lichen planus, vitiligo, and rarely pemphigus), **psoriasis remains the classic and most frequent example** in clinical practice and medical education. *Lupus vulgaris* - This is a chronic and progressive form of **cutaneous tuberculosis**, characterized by reddish-brown plaques with an "apple jelly" appearance on diascopy. - While skin trauma can sometimes trigger or worsen infections, **Koebner's phenomenon is not a characteristic feature** of lupus vulgaris. *Pemphigus vulgaris* - Pemphigus vulgaris is an **autoimmune blistering disease** affecting the skin and mucous membranes. - It is **primarily characterized** by flaccid blisters that rupture easily and a positive **Nikolsky's sign** (epidermis detaches with slight lateral pressure). - While Koebner's phenomenon has been rarely reported in pemphigus, **Nikolsky's sign is the pathognomonic feature**, not Koebner's phenomenon. *Pityriasis rosea* - This is a common, acute, self-limiting skin eruption that typically begins with a **herald patch** followed by smaller, oval, fine-scaling patches in a **'Christmas tree' pattern** on the trunk. - Its etiology is thought to be viral, and it **does not exhibit Koebner's phenomenon**.

Question 108: A patient with chronic plaque psoriasis develops an adverse response to therapy. Which response indicates treatment with hydroxychloroquine?

A. Sudden generalized flare (Correct Answer)
B. Localized plaque thickening
C. Palmoplantar involvement
D. Development of pustules

Explanation: ***Sudden generalized flare*** - Hydroxychloroquine, while sometimes used for **psoriatic arthritis**, is notorious for exacerbating cutaneous psoriasis, typically causing a **sudden generalized flare** of the disease. - This adverse effect is particularly significant in patients with plaque psoriasis, making hydroxychloroquine a **relative contraindication** in many cases. - This is the **most characteristic** adverse response to antimalarial therapy in psoriasis patients. *Localized plaque thickening* - This is a common feature of chronic plaque psoriasis itself and does not specifically indicate a response to hydroxychloroquine. - Plaque thickening can occur with disease progression or insufficient treatment but is not a recognized side effect of hydroxychloroquine. *Palmoplantar involvement* - **Palmoplantar psoriasis** is a specific morphological variant of the disease and is not a direct response to hydroxychloroquine treatment. - While it can be severe and difficult to treat, its presence does not signify a drug-induced phenomenon related to hydroxychloroquine. *Development of pustules* - While hydroxychloroquine can rarely trigger transformation to **pustular psoriasis**, this is less common than the typical presentation of acute generalized plaque exacerbation. - **Sudden generalized flare** of plaque psoriasis remains the most characteristic adverse response to hydroxychloroquine, making it the best answer among the options provided.

Question 109: A 50-year-old man with severe plaque psoriasis presents with worsening erythroderma and pustules despite recently starting cyclosporine. Labs show leukocytosis and elevated CRP. Most appropriate next step is:

A. Switch to methotrexate
B. Hospitalize for systemic therapy (Correct Answer)
C. Start oral retinoids
D. Continue cyclosporine and add topical steroids

Explanation: ***Hospitalize for systemic therapy*** - The presentation of **erythroderma** and **pustules** with **leukocytosis** and **elevated CRP** in a patient with severe psoriasis suggests **generalized pustular psoriasis** (von Zumbusch) or **erythrodermic psoriasis**, both life-threatening emergencies. - This requires **immediate hospitalization** for close monitoring, fluid and electrolyte management, temperature regulation, infection surveillance, and aggressive systemic therapy (often including biologics, systemic steroids, or combination therapy). - The severity with systemic inflammation mandates inpatient care rather than outpatient management. *Switch to methotrexate* - While **methotrexate** is effective for severe psoriasis, this patient is hemodynamically unstable with systemic inflammation requiring immediate inpatient monitoring and rapid intervention. - Methotrexate has a **slow onset of action** (weeks) and would not provide the urgent control needed for this acute emergency. - Outpatient drug switching is inappropriate for an unstable patient with erythroderma. *Start oral retinoids* - **Acitretin** is used for pustular psoriasis, but has **delayed onset** (2-3 months for full effect) and would be insufficient as monotherapy for this acute, life-threatening presentation. - The patient requires immediate hospitalization and faster-acting therapies, possibly including biologics or short-term systemic corticosteroids. *Continue cyclosporine and add topical steroids* - The disease is clearly not controlled on cyclosporine alone, and **topical steroids are inadequate** for managing widespread erythroderma with systemic inflammation. - This severe presentation requires **escalation to inpatient systemic therapy**, not continuation of an inadequate outpatient regimen.

Question 110: 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.

Practice by Chapter

Pathophysiology of Psoriasis

Practice Questions

Psoriasis Vulgaris

Practice Questions

Guttate Psoriasis

Practice Questions

Erythrodermic Psoriasis

Practice Questions

Pustular Psoriasis

Practice Questions

Palmoplantar Psoriasis

Practice Questions

Nail Psoriasis

Practice Questions

Scalp Psoriasis

Practice Questions

Psoriatic Arthritis

Practice Questions

Topical Therapy for Psoriasis

Practice Questions

Systemic Therapy for Psoriasis

Practice Questions

Phototherapy and Biologics for Psoriasis

Practice Questions

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Psoriasis — MCQs

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