Bacterial Skin Infections Practice Questions

Q: Characteristic of primary chancre:

Painless punched out ulcer. ***Painless punched out ulcer*** - A primary chancre of **syphilis** typically presents as a **painless ulcer**. - Its appearance is often described as **punched out**, with sharp, raised borders and a clean base. *Painful ulcer with undermined edges* - This description is more characteristic of a **chancroid**, caused by *Haemophilus ducreyi*. - Chancroids are typically **painful** and often have **undermined edges** with a grey or necrotic base. *Painless ulcer with rolled edges* - While a primary chancre is painless, it does not typically have **rolled edges**. - **Rolled edges** are more often associated with **basal cell carcinoma**, a cancerous lesion. *Painful punched out ulcer* - The combination of a **painful** ulcer that is **punched out** is not characteristic of a primary chancre due to syphilis. - Primary chancres are classically **painless**.

Q: The standard regimen for satisfactory treatment of paucibacillary leprosy consists of

Dapsone and rifampicin for 6 months. ***Dapsone and rifampicin for 6 months*** - The standard **multidrug therapy (MDT)** for **paucibacillary (PB) leprosy** involves a combination of **Dapsone** and **Rifampicin**. - This regimen is administered for a duration of **6 months** to achieve satisfactory treatment and prevent resistance. *Dapsone alone for 12 months* - **Monotherapy** with Dapsone is **not recommended** for leprosy due to the high risk of developing **drug resistance**. - While Dapsone is a component, it must be combined with other drugs. *Dapsone and ethionamide for 12 months* - **Ethionamide** is typically used as a second-line drug, primarily in cases of **multidrug-resistant leprosy** or specific treatment failures. - It is not part of the standard initial regimen for paucibacillary leprosy. *Dapsone and clofazimine for 6 months* - The combination of **Dapsone and Clofazimine** is part of the standard regimen for **multibacillary (MB) leprosy**, not paucibacillary. - While Clofazimine is effective, it is withheld for PB leprosy to minimize drug burden and side effects, as these patients have a lower bacterial load.

Q: Thalidomide is drug of choice for -

Lepra II reaction. ***Lepra II reaction*** - **Thalidomide** is highly effective in treating **erythema nodosum leprosum (ENL)**, also known as Lepra II reaction. - It works by modulating the immune response, reducing the severe inflammatory symptoms. *Nerve abscess* - **Nerve abscesses** in leprosy usually require surgical drainage and appropriate antibiotic treatment, not thalidomide. - They represent a localized collection of pus within a nerve, often associated with a **Type I reaction**. *Lepra I reaction* - **Type I reactions** (reversal reactions) are typically managed with corticosteroids to reduce inflammation and prevent nerve damage. - Thalidomide is not the primary treatment for these reactions, as their underlying immunological mechanism differs from Type II reactions. *Both* - Thalidomide is specific to **Lepra II reactions (ENL)** and is not the drug of choice for nerve abscesses or Lepra I reactions. - Treating both conditions with thalidomide would be inappropriate given their distinct pathologies and treatment protocols.

Q: Skin TB which involves skin after involving lymph nodes –

Scrofuloderma. ***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.

Q: Features of secondary syphilis are: a) Condyloma accuminata b) Condyloma lata c) Mulberry/Moon's molars d) Lesions over palms/soles

bd. ***bd*** - **Condyloma lata** are moist, wart-like lesions that appear in intertriginous areas (e.g., anogenital region, axillae) and are highly infectious manifestations of secondary syphilis [1]. - **Lesions over palms/soles** are classic mucocutaneous manifestations of secondary syphilis, characterized by a non-pruritic, maculopapular rash [1]. *ad* - **Condyloma accuminata** are genital warts caused by the **Human Papillomavirus (HPV)**, not syphilis. - While lesions over palms/soles are a feature of secondary syphilis, the inclusion of condyloma acuminata makes this option incorrect. *ac* - **Condyloma accuminata** are caused by **HPV**, making this option incorrect for syphilis. - **Mulberry/Moon's molars** are a feature of **congenital syphilis**, not secondary syphilis [1]. *bc* - While **condyloma lata** are characteristic of secondary syphilis, **Mulberry/Moon's molars** are a stigmata of **congenital syphilis** [1]. - This option incorrectly combines features of secondary and congenital syphilis.

Q: Ridley-Jopling classification includes all except:

Neuritic. ***Neuritic*** - The Ridley-Jopling classification focuses on the **polar spectrum** of immune response in leprosy and doesn't include "neuritic" as a distinct classification type within this framework. - While nerve involvement is a hallmark of leprosy, the classification system categorizes patients based on their **clinical and histopathological features** reflecting the host's immune response to *Mycobacterium leprae*. *Tuberculoid* - This is one of the **five main classifications** in the Ridley-Jopling spectrum, representing the pole with a strong cell-mediated immune response. - Characterized by **few lesions**, well-demarcated, and often associated with significant **nerve damage**. *Borderline borderline* - This represents the **mid-spectrum** between tuberculoid and lepromatous poles, indicating an unstable immune response. - Patients in this category often show features of both more resistant and more susceptible forms of the disease, with **moderately numerous lesions** and variable nerve involvement. *Lepromatous leprosy* - This is the other **polar extreme** of the Ridley-Jopling classification, characterized by a weak or absent cell-mediated immune response. - Patients have **numerous, diffuse lesions** with high bacterial loads and widespread nerve damage, though less severe clinically than tuberculoid leprosy initially.

Q: A 35 years old male came with a progressive plaque over buttock for the last 2 years. The plaque is annular in shape with scarring in centre. Most likely diagnosis is:

Lupus vulgaris. ***Lupus vulgaris*** - This is a chronic and progressive form of **cutaneous tuberculosis** characterized by plaques that often have a distinctive **annular shape** and can lead to **scarring, atrophy**, or even **ulceration** in the center. - The slow, progressive nature over two years, with a central scar, aligns well with the typical presentation of lupus vulgaris, especially in areas like the buttocks or face. *Kala azar* - Also known as **visceral leishmaniasis**, it primarily affects internal organs and is characterized by **fever, hepatosplenomegaly**, and **pancytopenia**. - While it can present with dermal lesions (post-kala azar dermal leishmaniasis), these are typically **nodular** or **macular**, not annular plaques with central scarring in the initial presentation. *Borderline leprosy* - Leprosy presents with diverse skin lesions, but these are typically characterized by **hypopigmented** or **erythematous patches/plaques** with **sensory loss**. - The lesions of borderline leprosy are generally not described as annular plaques with prominent central scarring in the absence of other typical neurological features. *Tinea corporis* - This is a superficial fungal infection of the skin, commonly presenting as an **annular (ring-shaped)** lesion with an **erythematous, scaly border** and central clearing. - However, tinea corporis rarely causes **significant scarring** and chronic, progressive plaques over two years are atypical for this condition, which is usually more acute and responsive to antifungal treatment.

Q: The incubation period of LGV is?

10-30 days. ***10-30 days*** - The incubation period for **Lymphogranuloma Venereum (LGV)**, which is caused by specific serovars of *Chlamydia trachomatis*, typically ranges from 10 to 30 days [1]. - This period reflects the time from exposure to the appearance of initial lesions, such as a **small, painless papule** or ulcer at the site of inoculation [1]. *30-90 days* - This period is generally too long for the primary incubation phase of LGV. - While later stages of LGV can manifest much later, the initial incubation before the appearance of primary lesions or regional lymphadenopathy is shorter. *7-10 days* - This period is generally too short for LGV; many other STIs, like **genital herpes**, may have an incubation period in this range. - LGV's characteristic spread to regional lymph nodes and its presentation generally require a slightly longer incubation. *3-7 days* - This incubation period is more characteristic of conditions like **gonorrhea** or **chancroid**, not LGV. - LGV's distinct pathogenesis, involving deeper tissue penetration and lymphatic spread, necessitates a longer initial period.

Q: Dharmendra's index and Jopling's classification deals with -

Leprosy. Leprosy - Dharmendra's index is a method for classifying leprosy based on the bacillary load in skin smears. - Jopling's classification is a widely used system that categorizes leprosy based on clinical, histological, and immunological features. Polio - Polio is a viral disease primarily affecting the nervous system, leading to paralysis, and is not classified by Dharmendra's index or Jopling's classification. - Diagnosis typically involves detecting the poliovirus in stool samples or throat swabs. Syphilis - Syphilis is a sexually transmitted bacterial infection caused by Treponema pallidum, which is diagnosed through serological tests and clinical presentation. - Its staging (primary, secondary, latent, tertiary) is distinct from the classification systems mentioned. TB - Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis, primarily affecting the lungs, and its classification relates to infection site and drug resistance. - Diagnosis involves sputum tests, chest X-rays, and PPD skin tests, which are unrelated to Dharmendra's index or Jopling's classification.

Q: Regarding Jarisch-Herxheimer reaction in syphilis treatment, which statement is FALSE?

Requires stopping antibiotic therapy. Regarding Jarisch-Herxheimer reaction in syphilis treatment, which statement is FALSE? ***Requires stopping antibiotic therapy*** - The **Jarisch-Herxheimer reaction (JHR)** is a transient immune-mediated response to endotoxins released by dying spirochetes after initiation of syphilis treatment. It is a sign that the treatment is working, and **antibiotic therapy should not be stopped**. - While supportive care (e.g., antipyretics, analgesics) may be necessary to manage symptoms like fever, chills, myalgia, and headache, stopping the antibiotic would interrupt appropriate syphilis treatment. *More common in secondary syphilis* - The **Jarisch-Herxheimer reaction** is indeed most common and severe in **secondary syphilis** due to the high spirochetemia and widespread dissemination of bacteria, leading to a greater antigen load and subsequent immune response. - Symptoms tend to be milder or absent in primary or latent syphilis. *Can cause fetal distress in pregnancy* - In pregnant women, the **Jarisch-Herxheimer reaction** can potentially induce **uterine contractions** and **fetal distress**, especially if it causes significant maternal fever or systemic inflammation. - Although treatment for syphilis is critical during pregnancy, careful monitoring and management of JHR symptoms are important to mitigate risks to the fetus. *Usually occurs within 24 hours of treatment* - The **Jarisch-Herxheimer reaction** typically has a rapid onset, manifesting within **4 to 12 hours** after the first dose of antisyphilitic medication and usually resolving spontaneously within **24 hours** [1]. - This acute, self-limiting nature is characteristic of the reaction.

Question 1

Characteristic of primary chancre:

Accepted Answer

Painless punched out ulcer

Answer

Painful ulcer with undermined edges

Answer

Painless ulcer with rolled edges

Answer

Painful punched out ulcer

Question 2

The standard regimen for satisfactory treatment of paucibacillary leprosy consists of

Accepted Answer

Dapsone and rifampicin for 6 months

Answer

Dapsone alone for 12 months

Answer

Dapsone and ethionamide for 12 months

Answer

Dapsone and clofazimine for 6 months

Question 3

Thalidomide is drug of choice for -

Accepted Answer

Lepra II reaction

Answer

Nerve abscess

Answer

Lepra I reaction

Answer

Both

Question 4

Skin TB which involves skin after involving lymph nodes –

Accepted Answer

Scrofuloderma

Answer

Lupus erythematosus

Answer

Lupus pernio

Answer

Lupus vulgaris

Question 5

Features of secondary syphilis are: a) Condyloma accuminata b) Condyloma lata c) Mulberry/Moon's molars d) Lesions over palms/soles

Accepted Answer

bd

Answer

ad

Answer

ac

Answer

bc

Question 6

Ridley-Jopling classification includes all except:

Accepted Answer

Neuritic

Answer

Tuberculoid

Answer

Borderline borderline

Answer

Lepromatous leprosy

Question 7

A 35 years old male came with a progressive plaque over buttock for the last 2 years. The plaque is annular in shape with scarring in centre. Most likely diagnosis is:

Accepted Answer

Lupus vulgaris

Answer

Kala azar

Answer

Borderline leprosy

Answer

Tinea corporis

Question 8

The incubation period of LGV is?

Accepted Answer

10-30 days

Answer

30-90 days

Answer

7-10 days

Answer

3-7 days

Question 9

Dharmendra's index and Jopling's classification deals with -

Accepted Answer

Leprosy

Answer

Polio

Answer

Syphilis

Answer

TB

Question 10

Regarding Jarisch-Herxheimer reaction in syphilis treatment, which statement is FALSE?

Accepted Answer

Requires stopping antibiotic therapy

Answer

More common in secondary syphilis

Answer

Can cause fetal distress in pregnancy

Answer

Usually occurs within 24 hours of treatment

Bacterial Skin Infections — MCQs

Bacterial Skin Infections — MCQs

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