Biological Agents in Dermatology — MCQs
Anti TNF is not used in –
All these drugs are known to exacerbate psoriasis, except:
Which interleukin is specifically secreted by Th17 cells?
Live vaccines are contraindicated in all except:
Which of the following statements is true regarding omalizumab?
N95 mask is used for:
What is the correct term for candidiasis of the penis?
A 25-year-old female presents with the following lesions in the axilla, as shown by the arrow:
The following lesion appears on the leg of a patient of ulcerative colitis. All are useful in management except:
A patient developed fixed drug eruptions after taking certain medications. Which of the following drugs is known to cause these skin lesions?
Biological Agents in Dermatology Indian Medical PG Practice Questions and MCQs
Question 1: Anti TNF is not used in –
- A. RA with HIV
- B. RA with HCV
- C. RA with pulmonary fibrosis
- D. RA with Hepatitis B (Correct Answer)
Explanation: ***RA with Hepatitis B*** - **Anti-TNF therapy** is generally contraindicated or used with extreme caution in patients with active or chronic **Hepatitis B viral (HBV)** infection due to the risk of HBV reactivation, which can lead to severe hepatitis and liver failure. - Patients undergoing anti-TNF treatment for **rheumatoid arthritis (RA)** and HBV co-infection require close monitoring and often prophylactic antiviral therapy to prevent reactivation. *RA with HIV* - **Anti-TNF agents** can be used cautiously in **HIV-positive RA patients** with well-controlled viral loads and appropriate monitoring. - While there is a theoretical risk of increased infection, the benefits often outweigh the risks in selected patients, and these drugs are not absolutely contraindicated. *RA with HCV* - The use of **anti-TNF therapy** in patients with **Hepatitis C viral (HCV)** infection and RA is generally considered safe if the HCV infection is stable or treated. - These agents have not been consistently shown to worsen HCV viral load or liver function, but close monitoring is advised. *RA with pulmonary fibrosis* - **Anti-TNF agents** are typically not contraindicated in RA patients with **pulmonary fibrosis**, though caution is advised with some disease-modifying antirheumatic drugs (DMARDs) that can induce lung toxicity [1]. - While there have been rare reports of new-onset or worsening pulmonary fibrosis with anti-TNF use, it is not a general contraindication for their use in established fibrosis [1].
Question 2: All these drugs are known to exacerbate psoriasis, except:
- A. Beta blocker
- B. Hydroxychloroquine
- C. Ciclosporin (Correct Answer)
- D. Lithium
Explanation: ***Ciclosporin*** - **Ciclosporin** is an immunosuppressant often used to **treat severe psoriasis**, not exacerbate it. - It works by inhibiting the activation of T-cells, which are central to the pathogenesis of psoriasis. *Beta blocker* - **Beta-blockers**, particularly non-selective ones like **propranolol**, can worsen existing psoriasis or induce new lesions. - The mechanism is thought to involve effects on beta-adrenergic receptors in the skin, leading to inflammation. *Hydroxychloroquine* - **Hydroxychloroquine**, an antimalarial and immunosuppressant, can trigger or exacerbate psoriasis, especially **pustular psoriasis**. - It likely affects keratinocyte proliferation and immune responses in the skin. *Lithium* - **Lithium** is a mood stabilizer that is known to exacerbate or trigger various forms of psoriasis, including **plaque psoriasis** and **pustular psoriasis**. - The mechanism is believed to involve alterations in cyclic AMP metabolism and arachidonic acid pathways within keratinocytes.
Question 3: Which interleukin is specifically secreted by Th17 cells?
- A. IFN Gamma
- B. IL6
- C. IL-17 (Correct Answer)
- D. IL-22
Explanation: ***IL22*** - Th17 cells predominantly secrete **IL-17** and also produce **IL-22**, which is significant in mucosal immunity and inflammation [1]. - **IL-22** plays a crucial role in the response to infections and in the pathogenesis of inflammatory diseases. *IL16* - IL-16 is primarily associated with **chemoattractant and regulatory functions** for lymphocytes and not directly secreted by Th17 cells. - It is involved in **eosinophil and T cell activation**, which is not characteristic of the Th17 response. *IFN Gamma* - IFN-gamma is mainly produced by **Th1 cells** and is critical for **cell-mediated immunity**, which is distinct from the function of Th17 cells. - It plays a role in activating **macrophages**, unlike Th17 cells which focus on **neutrophil recruitment** and inflammation. *IL6* - While IL-6 is a pro-inflammatory cytokine that can be involved in various immune responses, it is not primarily secreted by Th17 cells. - It is produced by a variety of cell types including fibroblasts and macrophages, acting as a mediator in the **acute phase response**. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 158-160.
Question 4: Live vaccines are contraindicated in all except:
- A. Breastfeeding mothers (Correct Answer)
- B. Pregnant women
- C. Immunocompromised patients
- D. Patients on high-dose immunosuppressants
Explanation: ***Breastfeeding mothers*** - Live vaccines are generally **safe for breastfeeding mothers** and their infants, as the vaccine viruses are not typically excreted in breast milk in levels that can infect the infant. - The benefits of vaccinating the mother outweigh any theoretical risks, and it can provide **passive immunity** to the infant through antibodies in breast milk. *Pregnant women* - Live vaccines are **contraindicated during pregnancy** due to the theoretical risk of transmitting the attenuated virus to the fetus and causing congenital infection. - Examples include **MMR** and **varicella vaccines**, which should be administered before or after pregnancy. *Immunocompromised patients* - Live vaccines are **contraindicated** in individuals with compromised immune systems due to the risk of the attenuated vaccine virus causing **disseminated infection** or severe disease. - This includes patients with **HIV/AIDS** (with low CD4 counts), congenital immunodeficiencies, and those undergoing active cancer treatment. *Patients on high-dose immunosuppressants* - These patients are considered **immunocompromised**, and live vaccines are **contraindicated** because their suppressed immune system may not be able to effectively control the attenuated vaccine virus, leading to severe infection. - Examples of such medications include high-dose corticosteroids, chemotherapy agents, and biologics that target immune cells.
Question 5: Which of the following statements is true regarding omalizumab?
- A. Anti-IgE
- B. Given subcutaneously
- C. Used as add-on therapy in moderate to severe asthma prophylaxis
- D. All of the options (Correct Answer)
Explanation: ***All of the options*** is correct because each statement is true: **Anti-IgE** - Omalizumab is a **humanized monoclonal antibody** that specifically targets and binds to **free IgE** in the circulation - By binding free IgE, it prevents IgE from attaching to **high-affinity receptors** on mast cells and basophils - This reduces the allergic cascade and prevents release of inflammatory mediators **Given subcutaneously** - Omalizumab is administered via **subcutaneous injection** only - Dosing is typically every **2 to 4 weeks** based on patient's body weight and baseline IgE levels - Not available in oral or intravenous formulations for asthma treatment **Used as add-on therapy in moderate to severe asthma prophylaxis** - FDA approved as **add-on maintenance treatment** for patients aged ≥6 years with **moderate to severe persistent allergic asthma** - Indicated when asthma is **inadequately controlled** with inhaled corticosteroids - Reduces frequency of asthma exacerbations and improves asthma control - Also approved for chronic spontaneous urticaria All three statements accurately describe omalizumab's mechanism, administration route, and clinical indication, making **"All of the options"** the correct answer.
Question 6: N95 mask is used for:
- A. respiratory droplets
- B. Dust
- C. aerosol (Correct Answer)
- D. in general
Explanation: ***aerosol*** - **N95 masks** are specifically designed to filter out at least 95% of **airborne particles** (aerosols) 0.3 microns or larger. - This level of filtration is crucial for protecting against diseases transmitted via **aerosolized droplets**, such as tuberculosis or COVID-19. *respiratory droplets* - While an N95 mask can filter respiratory droplets, it is primarily designed for smaller **aerosol particles** that can remain suspended in the air. - **Surgical masks** are generally adequate for blocking larger respiratory droplets, preventing splash and splatter. *Dust* - While an N95 mask can filter dust, it is an **overkill** for most common dust exposures. - A simple **dust mask** or even a surgical mask can provide adequate protection against larger dust particles. *in general* - This option is too broad; N95 masks are specifically used when there's a risk of exposure to **aerosolized infectious agents** or **fine particulate matter**. - Their use is typically reserved for settings where **aerosol-generating procedures** are performed or when caring for patients with **airborne diseases**.
Question 7: What is the correct term for candidiasis of the penis?
- A. Oral thrush
- B. No candidiasis present
- C. Candidal balanitis (Correct Answer)
- D. Leukoplakia
Explanation: ***Balanitis*** - **Candidiasis of the penis** is specifically referred to as Candidal balanitis, an inflammatory condition affecting the **glans penis**. - This term accurately describes the location and cause of the infection. *Oral thrush* - **Oral thrush** is candidiasis of the mouth, characterized by **white patches** on the tongue and oral mucosa. - This term refers to a different anatomical location and is not applicable to penile infection. *No candidiasis present* - This option is incorrect because candidiasis can indeed affect the penis, leading to a recognized clinical condition. - Symptoms like **redness, itching, and discharge** would indicate the presence of candidiasis. *Leukoplakia* - **Leukoplakia** is a condition characterized by **white patches** that develop on the mucous membranes of the mouth, tongue, or sometimes the genitals. - It is a **precancerous lesion** that is not caused by Candida infection, distinguishing it from balanitis.
Question 8: A 25-year-old female presents with the following lesions in the axilla, as shown by the arrow:
- A. Hidradenitis Suppurativa (Correct Answer)
- B. Acne fulminans
- C. Acne conglobata
- D. Fox-Fordyce disease
Explanation: ***Hidradenitis Suppurativa*** - This image displays typical features of Hidradenitis Suppurativa, including **inflamed nodules**, **abscesses**, and **sinus tracts** in the intertriginous region (axilla in this case). - The disease commonly affects areas with **apocrine glands** and is characterized by chronic inflammation and scarring. *Fox-Fordyce disease* - This condition involves an **obstruction of apocrine sweat ducts**, leading to pruritic papules in apocrine gland-bearing areas. - While it affects similar anatomical locations as hidradenitis suppurativa, it does not typically present with the same degree of inflammation, deep nodules, abscesses, or sinus tracts. *Acne fulminans* - This is a rare and severe form of **acne vulgaris** characterized by the sudden onset of aggressive, ulcerative, and extensively inflamed nodules, cysts, and plaques with systemic symptoms like fever and arthralgia. - It primarily affects the **face, chest, and back**, not typically the axilla, and is associated with systemic inflammation. *Acne conglobata* - A severe form of **nodulocystic acne** characterized by interconnected abscesses, cysts, and sinus tracts, often leaving significant scarring. - While it involves extensive inflammation and sinus tracts, it primarily affects the **trunk and face**, not characteristically the axilla as the primary site of presentation in images like this.
Question 9: The following lesion appears on the leg of a patient of ulcerative colitis. All are useful in management except:
- A. Steroids
- B. Sulfapyridine (Correct Answer)
- C. Procto-colectomy
- D. Infliximab
Explanation: ***Sulfapyridine*** - The image shows **pyoderma gangrenosum**, a painful ulcerative skin condition often associated with inflammatory bowel disease like ulcerative colitis. Among the given options, **sulfapyridine** has the **least established role** in pyoderma gangrenosum management. - **Sulfapyridine** is an inactive component of **sulfasalazine** and primarily acts as an **antibacterial agent**. While sulfasalazine has been reported in some PG cases, sulfapyridine alone is not a recognized treatment for the inflammatory, non-infectious nature of pyoderma gangrenosum. - Unlike the other options which have well-established roles, sulfapyridine lacks strong evidence for efficacy in PG. *Steroids* - **Corticosteroids** (oral or topical) are the **first-line treatment** for pyoderma gangrenosum due to their potent anti-inflammatory and immunosuppressive effects. - They help to reduce the inflammation and promote healing of the painful ulcers. *Procto-colectomy* - In cases of severe, refractory pyoderma gangrenosum associated with ulcerative colitis, **colectomy** can be a **definitive treatment** as it removes the underlying inflammatory trigger. - This surgical intervention is considered when medical therapies are unsuccessful or when the colonic disease itself necessitates surgery. *Infliximab* - **Infliximab**, a **TNF-alpha inhibitor**, is a biologic agent effective in treating both ulcerative colitis and pyoderma gangrenosum. - It is used in cases that are refractory to steroids or when patients cannot tolerate steroid therapy.
Question 10: A patient developed fixed drug eruptions after taking certain medications. Which of the following drugs is known to cause these skin lesions?
- A. Phenolphthalein
- B. Aspirin
- C. Dapsone
- D. All of the above (Correct Answer)
Explanation: **Explanation:** **Fixed Drug Eruption (FDE)** is a unique type of cutaneous drug reaction characterized by the recurrence of a lesion (usually a dusky red or violaceous macule) at the **exact same anatomical site** every time the offending drug is ingested. This occurs due to the persistence of **CD8+ memory T-cells** in the basal keratinocytes at the site of the lesion. **Why Option D is correct:** All three drugs listed are classic and high-yield triggers for FDE: * **Phenolphthalein:** Historically the most common cause (found in older laxatives). * **Aspirin (NSAIDs):** A very frequent trigger in clinical practice. * **Dapsone (Sulfonamides):** Sulfonamides are among the most common drug classes associated with FDE. **Analysis of Options:** * **Phenolphthalein:** Often presents as "bullous" FDE. * **Aspirin:** Along with other NSAIDs (like Ibuprofen and Naproxen), it is a leading cause of multi-focal FDE. * **Dapsone:** As a sulfone, it shares cross-reactivity patterns and is a well-documented cause. **High-Yield Clinical Pearls for NEET-PG:** 1. **Most Common Site:** The **glans penis** is the most common site for FDE, followed by the lips and palms. 2. **Commonest Causes (Overall):** NSAIDs, Sulfonamides (Cotrimoxazole), Tetracyclines, and Anticonvulsants. 3. **Clinical Feature:** Lesions often leave behind **post-inflammatory hyperpigmentation (PIH)** after healing. 4. **Refractory Period:** After an eruption, there is a brief refractory period where the drug may not cause a reaction. 5. **Diagnosis:** Primarily clinical; however, a **Patch Test** performed at the site of the previous lesion (not on the back) can confirm the offending agent.
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