Psoriasis Practice Questions

Q: A 60-year-old woman presents with red, scaly patches on her arms that bleed easily when scratched. This is a classic sign of which condition?

Psoriasis. ***Psoriasis*** - **Red, scaly patches** that **bleed easily when scratched** (known as the **Auspitz sign**) are **pathognomonic** for psoriasis. - Psoriasis is a **chronic autoimmune** skin condition characterized by accelerated skin cell turnover. *Seborrheic dermatitis* - Characterized by **greasy, yellow scales** on erythematous skin, often in areas with high sebaceous gland activity like the scalp, face, and chest. - It is typically **not associated with the Auspitz sign** or easily bleeding lesions. *Actinic keratosis* - Presents as **rough, scaly patches** on sun-exposed skin and is considered a **precancerous lesion**. - While scaly, it generally does not exhibit the classic vivid redness or **Auspitz sign** seen in psoriasis. *Lichen planus* - Characterized by **pruritic, purple, polygonal, planar papules** and plaques, often on the flexor surfaces of the wrists and ankles. - It may cause Lacy white patterns on mucous membranes (Wickham's striae) and **does not typically bleed easily** when scratched.

Q: Psoriatic arthritis most commonly involves which joint -

Distal interphalangeal joint. ***Distal interphalangeal joint*** - Psoriatic arthritis has a predilection for the **distal interphalangeal (DIP) joints**, a feature that helps distinguish it from other inflammatory arthropathies. - Involvement of the DIP joints often correlates with **nail psoriasis** and can lead to characteristic **"sausage digits"** (dactylitis). *Proximal interphalangeal joint* - While **proximal interphalangeal (PIP) joints** can be affected in psoriatic arthritis, it is not the most common or characteristic pattern of involvement. - PIP joint involvement is more typically associated with **rheumatoid arthritis**, although it can occur in a polyarticular presentation of psoriatic arthritis. *Wrist joint* - The **wrist joint** can be affected in psoriatic arthritis, particularly in more severe or polyarticular forms, but it is not the most common initial presentation. - Wrist involvement can lead to significant pain and functional impairment but is less specific to psoriatic arthritis compared to DIP joint involvement. *Metacarpophalangeal joint* - **Metacarpophalangeal (MCP) joints** are also less commonly affected as the primary site in psoriatic arthritis compared to the DIP joints. - MCP joint involvement is a hallmark of **rheumatoid arthritis**, where it often presents with symmetrical inflammation.

Q: Multiple psoriatic lesions on hands. Treatment of choice is?

Topical steroids with salicylic acid. ***Topical steroids with salicylic acid*** - For **localized psoriasis**, such as lesions primarily on the hands, **topical corticosteroids** are the first-line treatment due to their anti-inflammatory effects. - **Salicylic acid** helps with **keratolysis**, reducing the scaling associated with psoriatic plaques, thereby improving penetration of the steroid. *NBUVB* - **Narrowband UVB (NBUVB)** therapy is more suitable for **widespread plaque psoriasis** rather than localized lesions on the hands. - It requires frequent clinic visits and may not be practical or cost-effective for small, confined areas. *Systemic methotrexate* - **Systemic methotrexate** is reserved for **moderate to severe psoriasis** or psoriatic arthritis that is unresponsive to topical treatments or phototherapy. - Its use carries risks of **hepatotoxicity** and **bone marrow suppression**, making it inappropriate for localized disease. *Systemic steroids* - **Systemic corticosteroids** are generally avoided in psoriasis due to the risk of **rebound flares** or exacerbation of the disease upon withdrawal. - They are typically reserved for severe, acute flares and used with extreme caution, often as a bridge therapy.

Q: Woronoff's ring is specifically associated with which skin condition?

Psoriasis. ***Psoriasis*** - **Woronoff's ring** is a characteristic pale, blanching ring that can appear around resolving psoriatic plaques, especially after phototherapy or topical treatments. - It results from a local vasoconstriction or altered vascular response in the lesional skin as inflammation subsides. *Lichen planus* - Characterized by **purple, polygonal, pruritic papules and plaques**, often with **Wickham's striae** (fine white lines). - It does not present with Woronoff's ring. *Pityriasis rosea* - Presents with a **herald patch** followed by widespread small, oval, faint reddish-brown lesions arranged in a **"Christmas tree" pattern** on the trunk. - This condition is self-limiting and not associated with Woronoff's ring. *Pemphigus* - A group of **autoimmune blistering diseases** caused by antibodies against desmogleins, leading to **flaccid blisters** that rupture easily. - Clinical signs include Nikolsky's sign, but not Woronoff's ring.

Q: What is the treatment of choice for erythrodermic psoriasis?

Methotrexate. ***Methotrexate*** - **Methotrexate** is considered the first-line systemic treatment for erythrodermic psoriasis in most standard guidelines and medical textbooks. - It is an immunosuppressant that works by inhibiting folate metabolism, thereby reducing keratinocyte hyperproliferation and inflammatory processes. - It has an established efficacy profile, relatively rapid onset of action (4-8 weeks), and is cost-effective and widely accessible. *Prednisone* - While systemic corticosteroids like **prednisone** can acutely suppress inflammation, they are **contraindicated** in erythrodermic psoriasis due to high risk of **rebound flares** and potential worsening upon withdrawal. - Long-term systemic corticosteroid use carries significant side effects including osteoporosis, hypertension, and diabetes. *Acitretin* - **Acitretin** is an oral retinoid that can be effective for erythrodermic psoriasis, but has a **slower onset of action** (2-3 months) compared to methotrexate. - It carries significant **teratogenic risks** requiring strict contraception for 2-3 years after discontinuation in women of childbearing potential. - Side effects include mucocutaneous dryness, hyperlipidemia, and hepatotoxicity. *Biologics* - **Biologics** (anti-TNF, anti-IL-17, anti-IL-23 agents) are highly effective for severe psoriasis including erythrodermic forms. - They are typically considered **second-line** agents due to higher cost, limited availability in resource-constrained settings, need for parenteral administration, and potential for serious infections. - While increasingly used in modern practice, **methotrexate** remains the standard first-line systemic agent in most treatment protocols.

Q: Keratodermic sandals are associated with which of the following conditions?

Pityriasis rubra pilaris. ***Pityriasis rubra pilaris*** - **Keratodermic sandals** describe the characteristic **thickening and orange-red discoloration of the palms and soles** seen in pityriasis rubra pilaris. - This condition also typically presents with **follicular papules** and areas of normal skin (islands of sparing) amidst generalized erythema. *Pityriasis rosea* - Characterized by a **herald patch** followed by an eruption of oval, erythematous, scaly patches on the trunk and proximal extremities, often arranged in a **Christmas tree pattern**. - It does not involve significant palmar or plantar hyperkeratosis. *Lichen planus* - Manifests as **pruritic, purple, polygonal, planar papules and plaques** (the 6 P's), often affecting the wrists, ankles, and oral mucosa. - While it can involve nail changes and sometimes hyperkeratosis, the specific "keratodermic sandals" pattern is not characteristic. *Psoriasis* - Typically presents with well-demarcated, erythematous plaques covered by **silvery scales**, commonly on extensor surfaces, scalp, and nails. - Although palmoplantar psoriasis can occur, it's distinct from the diffuse, orange-red hyperkeratosis described as keratodermic sandals in pityriasis rubra pilaris.

Q: HLA-Cw6 is associated with

Psoriasis vulgaris. ***Psoriasis vulgaris*** - **HLA-Cw6** is the **strongest genetic risk factor** associated with an increased susceptibility to psoriasis vulgaris, particularly early-onset forms. - Its presence is linked to a more severe and widespread presentation of the disease. *Myasthenia gravis* - This autoimmune disorder is primarily associated with **HLA-DR3** and **HLA-B8**, and autoantibodies against the acetylcholine receptor. - While other HLA alleles may be involved, **HLA-Cw6** is not a primary or strong genetic association for myasthenia gravis. *Behcet's disease* - **HLA-B51** is the most significant genetic association with Behcet's disease, particularly in populations of Middle Eastern and East Asian descent. - Symptoms include **recurrent oral and genital ulcers**, **uveitis**, and skin lesions. *Pemphigus vulgaris* - This autoimmune blistering disease is strongly associated with **HLA-DR4** and **HLA-DRw6**, especially in individuals of Jewish descent. - It involves autoantibodies targeting **desmoglein 1 and 3**, leading to acantholysis within the epidermis.

Q: The Grattage test is used to diagnose which of the following conditions?

Psoriasis. ***Psoriasis*** - The **Grattage test** (candle grease sign) involves **scraping the psoriatic lesion** to reveal characteristic features - First reveals **fine, silvery-white scales** resembling candle wax - Further scraping exposes **pinpoint bleeding points** (**Auspitz sign**) due to exposure of dilated capillaries in dermal papillae - This combination is **pathognomonic for psoriasis** and helps differentiate it from other scaly dermatoses *Tinea capitis* - A **fungal infection of the scalp** caused by dermatophytes - Diagnosed by **KOH mount** (showing fungal hyphae), **fungal culture**, and sometimes **Wood's lamp examination** - The Grattage test is not used for diagnosing fungal infections *Lichen planus* - Characterized by **purplish, polygonal, flat-topped, pruritic papules and plaques** - Surface shows **Wickham's striae** (fine white lines) - Diagnosis is **clinical**, supported by **skin biopsy** showing band-like lymphocytic infiltrate and sawtooth rete ridges - The Grattage test is not applicable *Pemphigus vulgaris* - A severe **autoimmune blistering disorder** with **suprabasal acantholysis** - Presents with **flaccid bullae** that rupture easily, leaving erosions - Diagnosed by **skin biopsy**, **direct immunofluorescence** (intercellular IgG and C3 deposits), and **Nikolsky's sign** (positive) - The Grattage test is not used for bullous disorders

Q: In which of the following conditions is the Koebner phenomenon most commonly observed?

Psoriasis. ***Correct: Psoriasis*** - **Psoriasis** is the **most classic and commonly cited example** of the Koebner phenomenon (isomorphic response) - New psoriatic plaques characteristically develop at sites of cutaneous trauma, scratches, or surgical incisions in 25-50% of psoriasis patients - This is a **pathognomonic feature** frequently tested in competitive exams and considered the prototype condition for demonstrating this phenomenon - The mechanism involves inflammatory cascades triggered by trauma in genetically predisposed skin *Incorrect: Lichen planus* - While lichen planus does exhibit the Koebner phenomenon with purplish polygonal papules appearing along scratch lines, it is **less commonly observed** compared to psoriasis - Seen in approximately 10-25% of lichen planus cases - Not considered the primary example when teaching about Koebner phenomenon *Incorrect: Viral warts* - Viral warts can demonstrate **pseudo-Koebner phenomenon** where new warts form along trauma lines due to viral inoculation - This is more accurately described as **autoinoculation** rather than true isomorphic response - Less commonly discussed in the context of classic Koebner phenomenon compared to psoriasis *Incorrect: All of the options* - While all three conditions can show Koebner-like responses, the question asks for "**most commonly observed**" - Psoriasis remains the **gold standard** and most frequently encountered example in clinical practice and medical literature

Q: Which HLA allele is most strongly associated with psoriasis?

HLA CW6. ***HLA CW6*** - **HLA-Cw6** is the most strongly associated **HLA allele** with **psoriasis**, particularly with Type I (early-onset) psoriasis. - Its presence is linked to a more severe and widespread form of the disease. *HLA B27* - **HLA-B27** is strongly associated with **spondyloarthropathies** like **ankylosing spondylitis** and **reactive arthritis**, not directly with psoriasis itself, although it can be present in psoriatic arthritis. - Its primary role is in conditions affecting the **axial skeleton** and **entheses**. *HLA DR4* - **HLA-DR4** is a significant genetic marker for **rheumatoid arthritis** and **Type 1 diabetes**. - It is not directly associated with the pathogenesis of psoriasis. *HLA B8* - **HLA-B8** is associated with various autoimmune diseases such as **celiac disease**, **myasthenia gravis**, and **lupus erythematosus**. - It does not have a direct or strong association with psoriasis.

Question 1

A 60-year-old woman presents with red, scaly patches on her arms that bleed easily when scratched. This is a classic sign of which condition?

Accepted Answer

Psoriasis

Answer

Seborrheic dermatitis

Answer

Actinic keratosis

Answer

Lichen planus

Question 2

Psoriatic arthritis most commonly involves which joint -

Accepted Answer

Distal interphalangeal joint

Answer

Proximal interphalangeal joint

Answer

Wrist joint

Answer

Metacarpophalangeal joint

Question 3

Multiple psoriatic lesions on hands. Treatment of choice is?

Accepted Answer

Topical steroids with salicylic acid

Answer

NBUVB

Answer

Systemic methotrexate

Answer

Systemic steroids

Question 4

Woronoff's ring is specifically associated with which skin condition?

Accepted Answer

Psoriasis

Answer

Lichen planus

Answer

Pityriasis rosea

Answer

Pemphigus

Question 5

What is the treatment of choice for erythrodermic psoriasis?

Accepted Answer

Methotrexate

Answer

Acitretin

Answer

Prednisone

Answer

Biologics

Question 6

Keratodermic sandals are associated with which of the following conditions?

Accepted Answer

Pityriasis rubra pilaris

Answer

Lichen planus

Answer

Psoriasis

Answer

Pityriasis rosea

Question 7

HLA-Cw6 is associated with

Accepted Answer

Psoriasis vulgaris

Answer

Behcet's disease

Answer

Pemphigus vulgaris

Answer

Myasthenia gravis

Question 8

The Grattage test is used to diagnose which of the following conditions?

Accepted Answer

Psoriasis

Answer

Tinea capitis

Answer

Lichen planus

Answer

Pemphigus vulgaris

Question 9

In which of the following conditions is the Koebner phenomenon most commonly observed?

Accepted Answer

Psoriasis

Answer

Lichen planus

Answer

All of the options

Answer

Viral warts

Question 10

Which HLA allele is most strongly associated with psoriasis?

Accepted Answer

HLA CW6

Answer

HLA B27

Answer

HLA DR4

Answer

HLA B8

Psoriasis — MCQs

Psoriasis — MCQs

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