Cutaneous Tuberculosis — MCQs

10 questions

Apple jelly nodule on diascopy is a feature of:

A 25-year-old female has been diagnosed to be suffering from tuberculosis categorized as category II (sputum +ve) case of relapse. According to the previous RNTCP (Revised National Tuberculosis Control Programme) guidelines, the treatment regimen recommended under DOTS was:

Which of the following chest X-ray findings is least likely to be associated with tuberculosis in patients with HIV?

Which of the following drugs used in anti-tubercular therapy is a potent bactericidal agent that inhibits RNA synthesis?

A farmer has an ulcer on leg with indurated margin and multiple sinuses with discharging granules. The likely diagnosis is -

Not a cutaneous manifestation of tuberculosis:

Skin TB which involves skin after involving lymph nodes –

Saddle nose deformity is seen in?

A patient presents with fever and a rim-enhancing lesion with an air-fluid level on brain CT. What is the most likely diagnosis?

Q10

A 40-year-old with HIV presents with fever, cough, and hypoxia. Chest X-ray shows bilateral infiltrates. What is the most likely diagnosis?

Cutaneous Tuberculosis Indian Medical PG Practice Questions and MCQs

Question 1: Apple jelly nodule on diascopy is a feature of:

A. Aspergillosis
B. Lupus vulgaris (Correct Answer)
C. Erysipelas
D. Rhinoscleroma

Explanation: ***Lupus vulgaris*** - An **apple jelly nodule** on diascopy is a classic clinical sign of **lupus vulgaris**, a severe form of cutaneous tuberculosis. - Diascopy reveals the characteristic yellowish-brown discoloration due to **tuberculous granulomas** in the dermis. *Aspergillosis* - This is a fungal infection that typically affects the **respiratory tract** and less commonly the skin, especially in immunocompromised individuals. - Skin lesions in aspergillosis are usually **necrotic ulcers** or plaques, not apple jelly nodules on diascopy. *Erysipelas* - This is a **superficial bacterial infection** of the skin and subcutaneous tissue, typically caused by *Streptococcus pyogenes*. - It presents as a bright red, swollen, raised lesion with a **distinct border**, and does not produce apple jelly nodules. *Rhinoscleroma* - This is a chronic, progressive granulomatous disease affecting the **upper respiratory tract**, caused by *Klebsiella rhinoscleromatis*. - It leads to **hard, nodular masses** in the nose and pharynx, often described as ligneous, but does not present as apple jelly nodules on diascopy.

Question 2: A 25-year-old female has been diagnosed to be suffering from tuberculosis categorized as category II (sputum +ve) case of relapse. According to the previous RNTCP (Revised National Tuberculosis Control Programme) guidelines, the treatment regimen recommended under DOTS was:

A. 3(HRZE)3 + 2(HRE)3 + 4(HR)3
B. 2(HRSZE)3 + 1(HRZE)3 + 5(HRE)3 (Correct Answer)
C. 3(HRSZE)3 + 1(HRZE)3 + 6(HRE)3
D. 2(HRZE)3 + 5(HR)3

Explanation: ***2(HRSZE)3 + 1(HRZE)3 + 5(HRE)3*** - This regimen reflects the standard **Category II DOTS regimen** under the **previous RNTCP guidelines** for **sputum-positive relapse cases**, which was an 8-month treatment protocol. - The intensive phase consisted of **2 months of daily Streptomycin, Isoniazid, Rifampicin, Pyrazinamide, and Ethambutol (HRSZE)**, followed by **1 month of daily Isoniazid, Rifampicin, Pyrazinamide, and Ethambutol (HRZE)**, and a continuation phase of **5 months of Isoniazid, Rifampicin, and Ethambutol (HRE)** given three times weekly. - **Note:** Under current NTEP (National TB Elimination Programme) guidelines, previously treated cases undergo drug susceptibility testing, and fixed Category II regimens are no longer the standard approach. *3(HRZE)3 + 2(HRE)3 + 4(HR)3* - This is an incorrect combination of drugs and durations that does not match any standard DOTS category under previous RNTCP guidelines. - Category II relapse cases required a five-drug intensive phase including Streptomycin, not a four-drug regimen. *3(HRSZE)3 + 1(HRZE)3 + 6(HRE)3* - While this option includes the correct five-drug intensive phase, the duration is incorrect—the intensive phase with Streptomycin should be **2 months, not 3 months**. - The continuation phase of 6 months (instead of 5 months) also makes the total treatment duration longer than the standard 8-month Category II protocol. *2(HRZE)3 + 5(HR)3* - This regimen represents the **Category I (new cases) regimen** under previous RNTCP guidelines, which used only four drugs in the intensive phase. - It **lacks Streptomycin**, which was essential for Category II (relapse/failure/treatment after default) cases, and the continuation phase lacks Ethambutol, which was included in Category II continuation.

Question 3: Which of the following chest X-ray findings is least likely to be associated with tuberculosis in patients with HIV?

A. Pleural effusion
B. Hilar lymphadenopathy
C. Lupus vulgaris (Correct Answer)
D. Miliary pattern

Explanation: ***Lupus vulgaris*** * **Lupus vulgaris** is a form of **cutaneous tuberculosis** that affects the skin and is not a chest X-ray finding. * It is a localized skin lesion, typically on the face or neck, and does not manifest with pulmonary radiographic changes. *Miliary pattern* * **Miliary pattern** on chest X-ray appears as diffuse **small nodular infiltrates** (1-3 mm) distributed throughout both lung fields, representing hematogenous dissemination of *Mycobacterium tuberculosis*. * This finding is common in HIV patients with **disseminated (miliary) tuberculosis** and reflects severely impaired cell-mediated immunity. * The term "miliary" refers to the millet seed-like appearance of the nodules. *Pleural effusion* * **Pleural effusion** is a common manifestation of tuberculosis, especially in immunocompromised individuals like those with HIV, often appearing as blunting of the **costophrenic angles** on chest X-ray. * It is caused by an inflammatory reaction to mycobacterial antigens in the pleural space. *Hilar lymphadenopathy* * **Hilar lymphadenopathy** is a common chest X-ray finding in both primary and reactivated tuberculosis, particularly in HIV-infected patients due to an altered immune response. * Enlarged lymph nodes near the **hilum** are often prominently visible and can be a sole chest X-ray finding in early or atypical presentations.

Question 4: Which of the following drugs used in anti-tubercular therapy is a potent bactericidal agent that inhibits RNA synthesis?

A. Pyrazinamide
B. Ethambutol
C. PAS
D. Rifampicin (Correct Answer)

Explanation: ***Rifampicin*** - **Rifampicin** is a potent **bactericidal** anti-tubercular drug that inhibits bacterial **RNA synthesis** by binding to DNA-dependent RNA polymerase. - It is effective against both **rapidly dividing** and **metabolically active** *M. tuberculosis* strains. - Among first-line anti-TB drugs, it is considered the most potent bactericidal agent with sterilizing activity. *Pyrazinamide* - **Pyrazinamide** is **bactericidal** against **intracellular** and **slowly replicating** *M. tuberculosis* in acidic environments. - Its mechanism involves disrupting **mycobacterial membrane metabolism** and **transport functions** under acidic conditions, not RNA synthesis. - It has unique sterilizing activity against dormant bacilli. *Ethambutol* - **Ethambutol** is primarily **bacteriostatic**, inhibiting the synthesis of the **mycobacterial cell wall** by interfering with arabinosyl transferases. - It prevents the formation of **arabinogalactan**, an essential component of the mycobacterial cell wall. *PAS* - **Para-aminosalicylic acid (PAS)** is a **bacteriostatic** drug that inhibits **folic acid synthesis** in *M. tuberculosis*, similar to sulfonamides. - It is a **second-line agent** used primarily in cases of drug resistance.

Question 5: A farmer has an ulcer on leg with indurated margin and multiple sinuses with discharging granules. The likely diagnosis is -

A. Lupus vulgaris
B. Actinomycosis
C. Scrofuloderma
D. Mycetoma (Correct Answer)

Explanation: ***Mycetoma*** - This is the **correct diagnosis** characterized by the classic triad: **tumefaction** (swelling with indurated margin), multiple **draining sinuses**, and discharge of **granules**. - The **occupational history** (farmer with soil exposure) and **location on the leg** are highly suggestive of mycetoma, particularly common in agricultural workers. - The granules are **colonies of microorganisms** (either fungi [eumycetoma] or bacteria [actinomycetoma]) aggregated and encased in a cement-like matrix, a distinctive feature of this chronic infection. - **Key distinguisher**: Mycetoma has a predilection for the **lower extremities**, especially the foot and leg, in individuals with occupational soil exposure. *Actinomycosis* - Actinomycosis is a bacterial infection caused by *Actinomyces* species, which also forms abscesses and draining sinuses with characteristic **"sulfur granules."** - **Why incorrect**: While actinomycosis shares features of sinuses and granules, it most commonly affects the **cervicofacial (50-60%)**, **thoracic**, or **abdominal** regions. - **Leg involvement is rare** for actinomycosis, making mycetoma the more likely diagnosis in this clinical scenario. - The occupational history and typical location favor mycetoma over actinomycosis. *Lupus vulgaris* - This is a form of **cutaneous tuberculosis** presenting as red-brown plaques or nodules, often with an **"apple-jelly" appearance** on diascopy. - While it can cause ulcers, it typically does **not present with deep-seated sinuses and discharging granules**, which are pathognomonic for mycetoma. *Scrofuloderma* - This is a form of cutaneous tuberculosis that develops from the direct extension of underlying **tuberculous adenitis** or **osteomyelitis** to the skin. - It presents as cold abscesses that eventually rupture, forming irregular ulcers and sinuses, but typically **lacks the distinct discharging granules** of mycetoma. - The clinical presentation with granular discharge clearly differentiates mycetoma from scrofuloderma.

Question 6: Not a cutaneous manifestation of tuberculosis:

A. Exanthematous lesion
B. Scrofuloderma
C. Lupus vulgaris
D. Erythema migrans (Correct Answer)

Explanation: ***Erythema migrans*** - This **bullseye-shaped rash** is the hallmark cutaneous manifestation of **Lyme disease**, caused by *Borrelia burgdorferi*, not tuberculosis. - Its presence indicates exposure to **ticks** carrying the spirochete and is a distinct entity from mycobacterial infections. *Exanthematous lesion* - While not a specific term for TB, some forms of tuberculosis can present with a morbilliform or **exanthematous rash**, especially during disseminating or paradoxical reactions. - These are non-specific skin rashes that can occur in response to various infections, including but not exclusively tuberculosis. *Scrofuloderma* - This is a direct extension of tuberculosis from an underlying infected structure, such as a **lymph node (scrofula)** or bone, to the overlying skin. - It presents as **ulcers** or sinuses with undermining edges discharging pus, and is a definitive cutaneous manifestation of localized TB. *Lupus vulgaris* - This is a **chronic, progressive form of cutaneous tuberculosis** characterized by reddish-brown plaques with an "apple-jelly" color on diascopy. - It typically affects the face and neck and is caused by **hematogenous or lymphatic spread** from an internal TB focus in a patient with moderate to high immunity.

Question 7: Skin TB which involves skin after involving lymph nodes –

A. Scrofuloderma (Correct Answer)
B. Lupus erythematosus
C. Lupus pernio
D. Lupus vulgaris

Explanation: ***Scrofuloderma*** - This form of **cutaneous tuberculosis** results from the direct extension of underlying **tuberculosis** affecting structures such as **lymph nodes**, bones, or joints to the overlying skin. - The skin lesion often appears as an **ulcer** or **sinus tract** with **purulent discharge**, reflecting the underlying infection communicating with the surface. *Lupus erythematosus* - Lupus erythematosus is a systemic autoimmune disease that can affect the skin, but it is not a form of **tuberculosis**. - Skin manifestations range from acute malar rashes to chronic discoid lesions, which are distinct from **tuberculous ulcers**. *Lupus pernio* - This is a cutaneous manifestation of **sarcoidosis**, characterized by **violaceous plaques** and nodules typically on the face (nose, cheeks), ears, and fingers. - It is not a form of **tuberculosis** and does not result from the direct extension of an underlying local infection. *Lupus vulgaris* - This is a chronic and progressive form of **cutaneous tuberculosis** that directly affects the skin in individuals with high immunity to the **tubercle bacillus**. - It presents as **reddish-brown plaques** with an **apple-jelly** nodule appearance on diascopy, and does not typically arise from an underlying lymph node infection extending to the skin.

Question 8: Saddle nose deformity is seen in?

A. Primary Syphilis
B. Secondary Syphilis
C. Tertiary Syphilis (Correct Answer)
D. Lupus Vulgaris

Explanation: ***Tertiary Syphilis*** - **Saddle nose deformity** is a characteristic late manifestation of **tertiary syphilis** due to destructive lesions (gummas) affecting the nasal cartilage and bone [1], [2]. - It results from the **collapse of the nasal bridge**, leading to a flattened appearance [2]. *Primary Syphilis* - Characterized by a **chancre**, a painless ulcer, usually at the site of infection [1]. - This stage does not involve destructive lesions of the nose. *Secondary Syphilis* - Presents with a **widespread rash**, lymphadenopathy, and mucous patches [1]. - While systemic, it typically does not cause structural damage like saddle nose deformity. *Lupus Vulgaris* - This is a **cutaneous form of tuberculosis**, characterized by chronic, destructive skin lesions. - While it can cause facial disfigurement, saddle nose deformity is not a typical feature of lupus vulgaris.

Question 9: A patient presents with fever and a rim-enhancing lesion with an air-fluid level on brain CT. What is the most likely diagnosis?

A. Glioblastoma
B. Metastasis
C. Tuberculoma
D. Brain abscess (Correct Answer)

Explanation: ***Brain abscess*** - The presence of **fever** points towards an infectious etiology, and a **rim-enhancing lesion with an air-fluid level** on CT is highly characteristic of a brain abscess. The air-fluid level suggests gas-forming organisms or communication with an air-containing structure like a paranasal sinus. - An abscess is a collection of pus, and the "rim-enhancement" indicates the inflammatory capsule surrounding the infection, while the **air-fluid level** is virtually pathognomonic for an abscess containing gas. *Glioblastoma* - While glioblastoma can be a **rim-enhancing lesion**, it is a primary brain tumor and typically does not present with **fever** or an **air-fluid level**. - It often shows **irregular, thick enhancement** and typically causes significant surrounding edema, but the key differentiating factors here are the fever and air-fluid level. *Metastasis* - Brain metastases often present as **multiple, rim-enhancing lesions**, but they are tumors and do not typically cause **fever** (unless very large with extensive necrosis) or exhibit **air-fluid levels**. - The clinical context (e.g., history of cancer) would be important for metastasis, but the **air-fluid level** strongly differentiates this case. *Tuberculoma* - A tuberculoma is a **granulomatous lesion** that can also show **rim enhancement**, especially with central caseous necrosis. However, it typically does not present with an **air-fluid level**. - While fever can be present in tuberculosis, the **air-fluid level** is the most discriminating feature pointing away from tuberculoma and towards an abscess.

Question 10: A 40-year-old with HIV presents with fever, cough, and hypoxia. Chest X-ray shows bilateral infiltrates. What is the most likely diagnosis?

A. Tuberculosis
B. Bacterial pneumonia
C. Lung abscess
D. Pneumocystis pneumonia (Correct Answer)

Explanation: ***Pneumocystis pneumonia*** - In an HIV-positive individual with **fever, cough, hypoxia**, and **bilateral infiltrates** on chest X-ray, *Pneumocystis jirovecii* pneumonia (PJP) is the most likely diagnosis [1]. - PJP is an **opportunistic infection** common in immunocompromised patients, particularly those with **CD4 counts less than 200 cells/mm³** [1], [2]. *Tuberculosis* - While tuberculosis can occur in HIV patients, it typically presents with **upper lobe cavitary lesions** or localized infiltrates, not diffuse bilateral infiltrates as described [1]. - Granulomas and night sweats are also common, which are not mentioned here. *Bacterial pneumonia* - Bacterial pneumonia usually presents with **lobar consolidation** or more localized infiltrates, and while it can cause fever and cough, severe hypoxia with diffuse bilateral infiltrates is less typical in this context [1]. - Immunocompromised patients are susceptible to bacterial pneumonia but the presenting features heavily favor PJP. *Lung abscess* - A lung abscess typically appears as a **cavity with an air-fluid level** on chest X-ray, which is not consistent with the described **bilateral infiltrates**. - It often results from aspiration and is characterized by purulent sputum, which is not mentioned.

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