Psoriasis Practice Questions

Q: Efalizumab is used in the treatment of which of the following conditions?

Psoriasis. **Explanation:** **Efalizumab** is a recombinant humanized monoclonal antibody specifically designed for the treatment of moderate-to-severe plaque **Psoriasis**. **Mechanism of Action:** Efalizumab binds to the **CD11a** subunit of Leukocyte Function-associated Antigen-1 (**LFA-1**). By doing so, it inhibits the adhesion of T-lymphocytes to intercellular adhesion molecule-1 (ICAM-1). This prevents T-cell activation, trafficking into the dermis, and attachment to keratinocytes, thereby interrupting the inflammatory cascade central to psoriasis pathogenesis. **Analysis of Options:** * **Psoriasis (Correct):** It was the primary indication for Efalizumab due to its T-cell mediated pathology. * **Acne Vulgaris (Incorrect):** Acne is primarily a disorder of the pilosebaceous unit involving sebum production and *C. acnes* colonization; T-cell targeted biologics are not used. * **Atopic Dermatitis (Incorrect):** While T-cells are involved, Efalizumab is not an approved or standard treatment for AD (where Dupilumab, an IL-4/IL-13 inhibitor, is preferred). **High-Yield Clinical Pearls for NEET-PG:** * **Black Box Warning:** Efalizumab was voluntarily withdrawn from the market (2009) due to its association with **Progressive Multifocal Leukoencephalopathy (PML)**, a fatal demyelinating disease caused by the **JC virus**. * **Target:** CD11a (LFA-1). * **Other Biologics in Psoriasis:** * TNF-α inhibitors: Infliximab, Etanercept, Adalimumab. * IL-12/23 inhibitor: Ustekinumab. * IL-17 inhibitors: Secukinumab, Ixekizumab. * IL-23 inhibitors: Guselkumab, Risankizumab.

Q: Formation of multiple pinpoint bleeding spots on scratching the skin is characteristic of which condition?

Psoriasis. **Explanation:** The correct answer is **Psoriasis**. The phenomenon described—multiple pinpoint bleeding spots upon scratching or removing a scale—is known as **Auspitz sign**. **Why it occurs:** In psoriasis, there is marked epidermal hyperplasia (acanthosis) and thinning of the epidermis over the dermal papillae (suprapapillary thinning). Additionally, the dermal capillaries become dilated and tortuous. When the silvery-white scales are scraped off, the thin suprapapillary plate is breached, leading to the rupture of these underlying dilated capillaries, which results in pinpoint bleeding. **Analysis of Incorrect Options:** * **Pemphigus vulgaris:** Characterized by intraepidermal blisters due to acantholysis. The hallmark sign is **Nikolsky’s sign** (dislodgement of intact superficial epidermis by shear force). * **Lupus erythematosus:** Chronic Cutaneous LE (Discoid LE) shows "carpet tack" or "tin tack" signs (follicular plugging), but not pinpoint bleeding. * **Herpangina:** A viral infection (Coxsackie A) presenting with painful vesicles and ulcers in the posterior pharynx, unrelated to scaling or Auspitz sign. **NEET-PG High-Yield Pearls:** * **Grattage Test:** The clinical procedure of scraping a psoriatic lesion to elicit Auspitz sign. * **Candle Grease Sign:** As the scale is scraped, it becomes white and opaque, resembling a drop of candle wax. * **Koebner Phenomenon:** Development of new psoriatic lesions at sites of skin trauma (also seen in Vitiligo and Lichen Planus). * **Woronoff’s Ring:** A pale halo of blanched skin surrounding a healing psoriatic plaque.

Q: Wickham's striae are characteristic of which dermatological condition?

Lichen planus. **Explanation:** **Lichen Planus (Correct Answer):** Wickham’s striae are fine, whitish, lace-like patterns or reticulated lines seen on the surface of the papules and plaques in Lichen Planus. They are most visible on the buccal mucosa but can also be seen on cutaneous lesions after applying oil. Histologically, these striae correspond to **focal areas of hypergranulosis** (thickening of the granular layer) above the peaks of the saw-tooth rete ridges. **Incorrect Options:** * **Psoriasis:** Characterized by silvery-white micaceous scales and the **Auspitz sign** (pinpoint bleeding on scraping). Histology shows parakeratosis and regular elongation of rete ridges, not Wickham’s striae. * **Pityriasis Rosea:** Presents with a "Herald patch" followed by a "Christmas tree" distribution of lesions. The characteristic feature is a **collarette of scales** with the free edge pointing inwards. * **Eczema:** Primarily presents with erythema, edema, vesiculation (acute), and lichenification (chronic) due to scratching. It lacks the specific reticulate network of Lichen Planus. **NEET-PG High-Yield Pearls:** * **The 6 P’s of Lichen Planus:** Planar (flat-topped), Purple, Polygonal, Pruritic, Papules, and Plaques. * **Koebner Phenomenon:** Development of lesions along the site of trauma (also seen in Psoriasis and Vitiligo). * **Max-Joseph Spaces:** Small areas of separation between the epidermis and dermis due to basal cell degeneration. * **Civatte Bodies:** Shrunken, eosinophilic, apoptotic keratinocytes found in the lower epidermis/upper dermis.

Q: Test tube rete pegs are a characteristic feature of:

Dilantin hyperplasia. **Explanation:** The term **"test tube rete pegs"** refers to a specific histopathological pattern where the epithelial rete ridges become elongated, slender, and uniform in shape, resembling test tubes lined up in a rack. **1. Why Dilantin Hyperplasia is correct:** Dilantin (Phenytoin) is an anticonvulsant known to cause **gingival hyperplasia**. Histologically, this condition is characterized by significant epithelial hyperplasia with long, thin, and slender rete pegs extending deep into the underlying connective tissue. These are classically described as "test tube" or "finger-like" rete pegs. This is a result of increased fibroblast activity and collagen production induced by the drug. **2. Why other options are incorrect:** * **Lichen Planus:** Characterized by **"saw-tooth"** rete pegs due to the destruction of the basal cell layer (liquefactive degeneration) by a band-like lymphocytic infiltrate. * **Oral Submucous Fibrosis (OSMF):** Characterized by epithelial **atrophy** (thinning) and loss of rete pegs due to excessive collagen deposition and hyalinization in the subepithelial layers. * **Psoriasis (Comparison):** While Psoriasis also features elongated rete pegs, they are typically described as **"club-shaped"** or "regularly elongated" with thinning of the suprapapillary epithelium. **3. NEET-PG High-Yield Pearls:** * **Phenytoin (Dilantin):** Causes gingival enlargement in ~50% of users. Other drugs causing this include **Cyclosporine** and **Calcium Channel Blockers (Nifedipine)**. * **Auspitz Sign:** Bleeding when psoriasis scales are removed, due to thinning of the epithelium over dilated capillaries in the dermal papillae. * **Munro’s Microabscess:** Neutrophils in the stratum corneum (seen in Psoriasis). * **Kogoj’s Pustule:** Neutrophils in the stratum spinosum (seen in Psoriasis).

Q: Limpet-like cone-shaped lesions in psoriasis refer to which of the following conditions?

Rupioid psoriasis. **Explanation:** **Rupioid psoriasis** is the correct answer because it is characterized by highly inflammatory, thick, hyperkeratotic, and crusty lesions that are **cone-shaped or "limpet-like"** (resembling a mollusk shell). These lesions are typically circular, elevated, and have a dark, dirty appearance. They are often associated with severe disease or co-morbidities like HIV. **Analysis of Incorrect Options:** * **Elephantine psoriasis (B):** This refers to a chronic, stable form of psoriasis characterized by very large, thick, persistent plaques, usually on the lower limbs or trunk. It lacks the specific cone-shaped morphology of rupioid psoriasis. * **Ostraceous psoriasis (C):** These lesions are characterized by thick, exuberant scales that are concave and resemble an **oyster shell**. While similar to rupioid, the key distinction is the shape: Ostraceous is flatter and shell-like, whereas Rupioid is distinctly conical/limpet-like. * **Inverse psoriasis (D):** Also known as flexural psoriasis, this occurs in skin folds (axilla, groin). It is characterized by smooth, erythematous plaques **without scaling** due to the moist environment. **High-Yield Clinical Pearls for NEET-PG:** * **Auspitz Sign:** Pinpoint bleeding on removal of scales (due to thinning of suprapapillary plate). * **Grattage Test:** Scraping the lesion increases the visibility of silvery-white scales (candle grease sign). * **Koebner Phenomenon:** Development of psoriatic lesions at sites of trauma (also seen in Lichen Planus and Vitiligo). * **Histopathology:** Key features include **Munro’s microabscesses** (neutrophils in the stratum corneum) and **Kogoj’s pustules** (neutrophils in the stratum spinosum).

Q: What are the characteristic bodies found in Lichen planus?

Civatte bodies. **Explanation:** The correct answer is **Civatte bodies**. These are characteristic histopathological findings in **Lichen Planus (LP)**. **1. Why Civatte bodies are correct:** Lichen planus is a chronic inflammatory condition characterized by a T-cell mediated attack on basal keratinocytes. This leads to **liquefaction degeneration** of the basal layer. The damaged keratinocytes undergo apoptosis and shrink into eosinophilic, rounded, anucleated structures known as **Civatte bodies** (also called colloid or cytoid bodies). They are typically found in the lower epidermis or upper dermis and contain deposits of IgM. **2. Analysis of Incorrect Options:** * **HP (Henderson-Paterson) bodies:** These are large, intracytoplasmic inclusion bodies seen in **Molluscum Contagiosum**, caused by the Poxvirus. * **Warthin-Finkeldey bodies:** These are multinucleated giant cells with eosinophilic nuclear and cytoplasmic inclusions, characteristic of **Measles** (Rubeola). * **Negri bodies:** These are pathognomonic eosinophilic intracytoplasmic inclusions found in pyramidal cells of the hippocampus and Purkinje cells of the cerebellum in **Rabies**. **3. High-Yield Clinical Pearls for NEET-PG:** * **Histopathology of LP:** Remember the mnemonic **"SAW"**: **S**aw-tooth rete ridges, **A**canthosis, and **W**ickham striae (clinically). Other features include hypergranulosis and a band-like lymphocytic infiltrate at the dermo-epidermal junction. * **Clinical 6 P’s of LP:** Planar, Purple, Polygonal, Pruritic, Papules, and Plaques. * **Koebner Phenomenon:** Positive in Lichen Planus, Psoriasis, and Vitiligo. * **Max Joseph Space:** Small areas of separation between the epidermis and dermis due to extensive basal cell degeneration in LP.

Q: Wickham's striae are seen in which of the following conditions?

Lichen planus. **Explanation:** **Lichen Planus (LP)** is the correct answer. **Wickham’s striae** are characteristic fine, whitish, lace-like reticular patterns seen on the surface of the violaceous papules and plaques of Lichen planus. They are most prominent on the buccal mucosa but can also be seen on cutaneous lesions after applying oil. **Pathophysiology:** These striae correspond histologically to **focal areas of hypergranulosis** (thickening of the granular layer) and orthokeratosis above the peaks of the "saw-tooth" rete ridges. **Analysis of Incorrect Options:** * **Lichen nitidus:** Characterized by tiny, shiny, skin-colored, pinhead-sized papules ("flesh-colored beads"). Histology shows a "claw clutching a ball" appearance, but Wickham’s striae are absent. * **Lichenoid eruption:** These are drug-induced rashes that mimic LP but usually lack the classic Wickham’s striae and often show eosinophils on biopsy. * **Lichen striatus:** A self-limiting linear dermatosis that follows the **Lines of Blaschko**, typically in children. It does not exhibit the reticular white network of LP. **NEET-PG High-Yield Pearls for Lichen Planus:** * **The 6 P’s:** Planar (flat-topped), Purple (violaceous), Polygonal, Pruritic, Papules, and Plaques. * **Koebner Phenomenon:** New lesions appear at the site of trauma (also seen in Psoriasis and Vitiligo). * **Histology:** Saw-tooth rete ridges, Civatte bodies (apoptotic keratinocytes), and a band-like lymphocytic infiltrate at the dermo-epidermal junction. * **Max-Joseph Spaces:** Small areas of separation between the epidermis and dermis due to basal cell degeneration.

Q: The Bulkeley membrane is a characteristic histological finding in which of the following conditions?

Psoriasis. **Explanation:** The correct answer is **Psoriasis**. **Understanding the Bulkeley Membrane:** The Bulkeley membrane is a clinical and histological feature observed during the **Auspitz sign** maneuver. In Psoriasis, there is significant parakeratosis (retention of nuclei in the stratum corneum) and thinning of the suprapapillary epidermis. When psoriasiform scales are scraped off layer by layer (Grate test), a thin, moist, transparent film of the lower epidermis is revealed—this is the **Bulkeley membrane**. Removing this membrane exposes the dilated, tortuous capillaries in the dermal papillae, leading to pinpoint bleeding (Auspitz sign). **Analysis of Incorrect Options:** * **Pemphigus:** This is an autoimmune blistering disease characterized by **acantholysis** (loss of intercellular connections) and the "row of tombstones" appearance on histology. It does not involve the Bulkeley membrane. * **Tinea:** A fungal infection characterized by hyphae and spores in the stratum corneum. While it presents with scaling, it lacks the specific epidermal thinning and vascular changes seen in psoriasis. * **Pityriasis:** Conditions like Pityriasis Rosea show "cigarette paper" scaling and a "herald patch," but do not exhibit the Auspitz sign or the Bulkeley membrane. **NEET-PG High-Yield Pearls for Psoriasis:** * **Munro’s Microabscess:** Collection of neutrophils in the stratum corneum. * **Kogoj’s Pustule:** Neutrophils in the stratum spinosum. * **Woronoff’s Ring:** A pale halo around a healing psoriatic plaque. * **Koebner Phenomenon:** Development of lesions at sites of trauma (also seen in Vitiligo and Lichen Planus). * **Histology Triad:** Acanthosis (epidermal thickening), Parakeratosis, and absent/diminished Stratum Granulosum.

Q: All of the following are seen in psoriasis except?

It is a premalignant disease. ### Explanation **Psoriasis** is a chronic, immune-mediated inflammatory skin disorder characterized by epidermal hyperproliferation. **Why Option C is the Correct Answer:** Psoriasis is **not a premalignant disease**. Unlike conditions such as Actinic Keratosis or Bowen’s disease, psoriasis does not inherently progress to malignancy. While chronic inflammation and certain treatments (like PUVA therapy) may slightly increase the risk of skin cancers (SCC/BCC), the disease itself is benign in nature. **Analysis of Incorrect Options:** * **A. Auspitz sign:** This is a classic diagnostic feature. When silvery scales are removed, pinpoint bleeding occurs due to the thinning of the suprapapillary epidermis and the presence of dilated, tortuous capillaries in the dermal papillae. * **B. 10% of cases are associated with arthritis:** Psoriatic arthritis (PsA) occurs in approximately **10–30%** of patients. It is typically seronegative (RF negative) and often involves the distal interphalangeal (DIP) joints. * **D. Worsening of disease during winter:** Psoriasis typically improves in summer due to beneficial UV radiation (which induces apoptosis of T-cells) and worsens in winter due to cold, dry air and lack of sunlight. **Clinical Pearls for NEET-PG:** * **Histopathology:** Look for Munro’s microabscesses (neutrophils in the stratum corneum) and Kogoj’s pustules (neutrophils in the stratum spinosum). * **Grattage Test:** Scraping the lesion increases the visibility of silvery scales (candle grease sign) before revealing the Auspitz sign. * **Koebner Phenomenon:** Development of new lesions at the site of trauma (also seen in Vitiligo and Lichen Planus). * **Woronoff’s Ring:** A pale halo around a healing psoriatic plaque.

Question 1

Efalizumab is used in the treatment of which of the following conditions?

Accepted Answer

Psoriasis

Answer

Acne vulgaris

Answer

Atopic dermatitis

Answer

All of the above

Question 2

Formation of multiple pinpoint bleeding spots on scratching the skin is characteristic of which condition?

Accepted Answer

Psoriasis

Answer

Pemphigus vulgaris

Answer

Lupus erythematosus

Answer

Herpangina

Question 3

Wickham's striae are characteristic of which dermatological condition?

Accepted Answer

Lichen planus

Answer

Psoriasis

Answer

Pityriasis rosea

Answer

Eczema

Question 4

What is the treatment of choice for pustular psoriasis?

Accepted Answer

Methotrexate

Answer

Psoralen plus ultraviolet A therapy (PUVA)

Answer

Systemic steroids

Answer

Estrogen

Question 5

Test tube rete pegs are a characteristic feature of:

Accepted Answer

Dilantin hyperplasia

Answer

Lichen planus

Answer

Oral submucous fibrosis

Answer

All of the above

Question 6

Limpet-like cone-shaped lesions in psoriasis refer to which of the following conditions?

Accepted Answer

Rupioid psoriasis

Answer

Elephantine psoriasis

Answer

Ostraceous psoriasis

Answer

Inverse psoriasis

Question 7

What are the characteristic bodies found in Lichen planus?

Accepted Answer

Civatte bodies

Answer

HP bodies

Answer

Warthin Finkeldy bodies

Answer

Negri bodies

Question 8

Wickham's striae are seen in which of the following conditions?

Accepted Answer

Lichen planus

Answer

Lichen nitidus

Answer

Lichenoid eruption

Answer

Lichen striatus

Question 9

The Bulkeley membrane is a characteristic histological finding in which of the following conditions?

Accepted Answer

Psoriasis

Answer

Pemphigus

Answer

Tinea

Answer

Pityriasis

Question 10

All of the following are seen in psoriasis except?

Accepted Answer

It is a premalignant disease

Answer

Auspitz sign

Answer

10% of cases are associated with arthritis

Answer

Worsening of disease during winter

Psoriasis — MCQs

Psoriasis — MCQs

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