Psoriasis Practice Questions

Q: Which of the following drugs is NOT used in the management of psoriasis?

Chloroquine. In the management of psoriasis, the goal is to inhibit keratinocyte proliferation and modulate the immune response. **Why Chloroquine is the correct answer:** Chloroquine (and Hydroxychloroquine) is an antimalarial drug that is notoriously known to **exacerbate or trigger psoriasis**. It can induce a flare-up of stable plaque psoriasis or even precipitate a life-threatening **erythrodermic or pustular transformation**. The mechanism is thought to involve the inhibition of the enzyme transglutaminase and the stimulation of interleukin-8, leading to epidermal hyperproliferation. Therefore, it is strictly avoided in psoriatic patients. **Why the other options are incorrect:** * **Psoralens (Option A):** These are photosensitizing agents used in **PUVA (Psoralen + UVA)** therapy. They intercalate into DNA to inhibit rapid cell division. * **Methotrexate (Option C):** A folic acid antagonist that acts as a potent immunosuppressant and cytotoxin. It is a **gold standard systemic treatment** for severe plaque psoriasis, psoriatic arthritis, and erythrodermic psoriasis. * **Coal Tar (Option D):** One of the oldest topical treatments (e.g., Goeckerman regimen). It has anti-inflammatory and keratoplastic properties that help normalize keratinization. **NEET-PG High-Yield Pearls:** * **Drugs that aggravate psoriasis (mnemonic: B-L-A-C-K):** **B**eta-blockers, **L**ithium, **A**ntimalarials (Chloroquine), **C**orticosteroids (withdrawal), and **K** (Potassium) sparing diuretics/NSAIDs. * **First-line for localized psoriasis:** Topical Vitamin D3 analogues (Calcipotriol) and Corticosteroids. * **Drug of choice for Psoriatic Arthritis:** Methotrexate (though biologics like Secukinumab are increasingly used).

Q: Which of the following conditions is characterized by the term 'Acanthosis nigricans'?

Psoriasis. **Explanation:** The term **Acanthosis** refers to the diffuse hyperplasia (thickening) of the stratum spinosum layer of the epidermis. In **Psoriasis**, this is a hallmark histopathological feature. Specifically, Psoriasis exhibits **regular elongation of rete ridges** (often described as "test-tube in a rack" appearance) due to the rapid turnover of keratinocytes. **Analysis of Options:** * **Psoriasis (Correct):** The histopathology is characterized by the triad of **Acanthosis**, **Parakeratosis** (retention of nuclei in the stratum corneum), and **Munro’s microabscesses** (neutrophils in the parakeratotic stratum corneum). * **Dermatomyositis:** Characterized by interface dermatitis, vacuolar degeneration of the basal layer, and dermal mucin. Clinical hallmarks include Gottron papules and Heliotrope rash. * **Systemic Lupus Erythematosus (SLE):** Shows liquefactive degeneration of the basal cell layer and follicular plugging, but not the regular acanthosis seen in psoriasis. * **Tinea versicolor:** A fungal infection (Malassezia) characterized by "spaghetti and meatballs" appearance on KOH mount; histopathology shows minimal epidermal change, primarily hyphae and spores in the stratum corneum. **High-Yield Clinical Pearls for NEET-PG:** * **Acanthosis Nigricans vs. Acanthosis:** Do not confuse "Acanthosis" (a histological term) with "Acanthosis Nigricans" (a clinical condition of hyperpigmented velvety plaques associated with insulin resistance or malignancy). * **Auspitz Sign:** Pinpoint bleeding when psoriasis scales are removed, due to thinning of the suprapapillary plate over dilated capillaries. * **Kogoj’s Pustule:** Neutrophils in the stratum spinosum (seen in pustular psoriasis). * **Grattage Test:** Scraping psoriasis lesions produces a candle-grease-like scale.

Q: Deficiency of which interleukin is associated with Ditra syndrome?

IL36. **Explanation:** **DITRA Syndrome** (Deficiency of IL-36 Receptor Antagonist) is a rare, life-threatening autoinflammatory disease characterized by recurrent episodes of generalized pustular psoriasis (GPP), high fever, and systemic inflammation. 1. **Why IL-36 is correct:** The syndrome is caused by a loss-of-function mutation in the **IL36RN gene**, which encodes the **IL-36 receptor antagonist (IL-36Ra)**. Normally, IL-36Ra acts as a "brake" by binding to the IL-36 receptor and blocking pro-inflammatory signaling. In DITRA, the absence of this antagonist leads to uncontrolled, overactive IL-36 signaling, resulting in massive recruitment of neutrophils and the formation of sterile pustules across the body. 2. **Why other options are incorrect:** * **IL-26:** A member of the IL-10 family involved in mucosal immunity and antimicrobial responses; it is not linked to DITRA. * **IL-46:** This is not a standard interleukin designation (Interleukins currently range from IL-1 to IL-40). * **IL-10:** An anti-inflammatory cytokine. While its deficiency can lead to early-onset inflammatory bowel disease (IBD), it is not the cause of DITRA. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Presentation:** Sudden onset of widespread sterile pustules on an erythematous base (von Zumbusch pattern), triggered by infections, stress, or pregnancy. * **Genetics:** Autosomal recessive inheritance. * **Treatment:** Targeted therapy with **Spesolimab** (an IL-36 receptor monoclonal antibody) is now the specific treatment of choice for GPP flares. * **Differential:** **DIRA** (Deficiency of IL-1 Receptor Antagonist) presents similarly but involves bone lesions (osteomyelitis) and is caused by mutations in the *IL1RN* gene.

Q: What is the definitive indication for systemic steroids in psoriasis?

Impetigo herpetiformis. ### Explanation **Correct Answer: D. Impetigo herpetiformis** **Why it is correct:** Impetigo herpetiformis is a rare, life-threatening variant of **pustular psoriasis occurring during pregnancy** (usually in the third trimester). It is considered a medical emergency due to risks of placental insufficiency, fetal demise, and maternal complications like hypocalcemia or sepsis. While systemic steroids are generally avoided in psoriasis, they are the **first-line systemic treatment** in this specific condition to rapidly control inflammation and protect both the mother and the fetus. **Why the other options are incorrect:** * **A & B (Pustular Psoriasis and Erythroderma):** Systemic steroids are strictly **contraindicated** in these conditions. Although they provide rapid initial clearance, their withdrawal frequently triggers a rebound flare-up, often transforming stable plaque psoriasis into life-threatening generalized pustular psoriasis (Von Zumbusch type). * **C (Psoriatic Arthropathy):** The mainstay of treatment for psoriatic arthritis includes NSAIDs and DMARDs (like Methotrexate or Leflunomide) and biologics (TNF-alpha inhibitors). Systemic steroids are not the definitive treatment and are avoided to prevent skin flares. **High-Yield Clinical Pearls for NEET-PG:** * **The "Steroid Rule":** In dermatology, psoriasis is the classic example where systemic steroids are avoided (except in Impetigo herpetiformis). * **Auspitz Sign:** Pinpoint bleeding on peeling a scale (absent in pustular/erythrodermic variants). * **Woronoff Ring:** A pale halo around a healing psoriasis plaque. * **Drug of Choice for Pustular Psoriasis:** Oral Retinoids (Acitretin) are preferred, but they are strictly contraindicated in pregnancy (teratogenic). This is why steroids are used for Impetigo herpetiformis instead.

Question 1

Which of the following drugs is NOT used in the management of psoriasis?

Accepted Answer

Chloroquine

Answer

Psoralens

Answer

Methotrexate

Answer

Coaltar

Question 2

A 24-year-old lady with a past history of psoriasis presents with fever and multiple pustular lesions in a generalized distribution. What is the drug of choice for managing her condition?

Accepted Answer

Methotrexate

Answer

Corticosteroids

Answer

Retinoids

Answer

Psoralen with PUVA

Question 3

Which of the following conditions is characterized by the term 'Acanthosis nigricans'?

Accepted Answer

Psoriasis

Answer

Dermatomyositis

Answer

Systemic Lupus Erythematosus (SLE)

Answer

Tinea versicolor

Question 4

Deficiency of which interleukin is associated with Ditra syndrome?

Accepted Answer

IL36

Answer

IL 26

Answer

IL 46

Answer

IL 10

Question 5

What is the definitive indication for systemic steroids in psoriasis?

Accepted Answer

Impetigo herpetiformis

Answer

Pustular psoriasis

Answer

Erythroderma

Answer

Psoriatic arthropathy

Psoriasis — MCQs

Psoriasis — MCQs

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