Bacterial Skin Infections Practice Questions

Q: Not a cutaneous manifestation of tuberculosis:

Erythema migrans. ***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.

Q: A patient has asymptomatic painless burrowing ulcer in the palate. He might be suffering from

Syphilis. ***Syphilis*** - A **painless burrowing ulcer** in the palate, particularly a **gumma**, is characteristic of tertiary syphilis. - While primary syphilis causes a chancre (also painless), the burrowing nature suggests a more advanced stage of the disease. *Actinomycosis* - Often presents as a **chronic, indurated, suppurative lesion** with draining sinuses, sometimes referred to as "lumpy jaw." - It’s typically associated with **yellow sulfur granules** and is usually painful or causes discomfort. *Tuberculosis* - Oral manifestations of tuberculosis are commonly seen as **painful, irregular ulcers** on the tongue or buccal mucosa. - Palatal lesions are less common and tend to be painful, unlike the case described. *Histoplasmosis* - Systemic histoplasmosis can manifest as **painful oral ulcers** or granulomatous lesions, often presenting with symptoms like fever, weight loss, and hepatosplenomegaly. - The ulcers are usually not described as "burrowing" and are typically painful.

Q: Painful matted suppurative lymphadenitis after healing of genital lesion is seen in:

LGV. **LGV** - **Lymphogranuloma venereum (LGV)** is caused by specific serovars of *Chlamydia trachomatis* and is characterized by a transient, painless genital ulcer followed by **painful, matted suppurative lymphadenopathy** in the inguinal region, often forming **buboes** and **fistulas** [1]. - The healing of the initial genital lesion before the onset of prominent lymphadenitis is a classic presentation of LGV [1]. *Syphilis* - While syphilis can cause **painless lymphadenopathy** (buboes), it is typically non-suppurative and does not result in the matted, suppurative nodes or fistula formation seen in LGV [2]. - The initial lesion, a **chancre**, is usually painless and firm [2]. *Donovanosis* - Donovanosis, caused by *Klebsiella granulomatis*, presents with **progressive, ulcerative lesions** that are highly vascular and bleed easily, not discrete genital lesions followed by prominent lymphadenitis [1]. - **Lymphadenitis** is rare; however, subcutaneous granulomas in the inguinal region (pseudobuboes) can occur, but these are not suppurative lymph nodes [1]. *Chancroid* - Chancroid, caused by *Haemophilus ducreyi*, characteristically causes **painful genital ulcers** and **painful, suppurative inguinal lymphadenitis** (buboes) [1]. - However, the lymphadenopathy usually appears concurrently with or shortly after the ulcer, and the ulcers are typically persistent and painful, unlike the transient, often unnoticed lesion of LGV [1].

Q: Apple jelly nodule on diascopy is a feature of:

Lupus vulgaris. ***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.

Q: A patient was diagnosed to have single skin lesion of Leprosy without any AFB positive bacteria from the scrapings. What should be the treatment of this patient according to latest guidelines?

(Rifampicin + Dapsone) for 6 months. ***(Rifampicin + Dapsone) for 6 months*** - This regimen is the standard **Multi-Drug Therapy (MDT)** for **paucibacillary (PB) leprosy**, which is characterized by a **single skin lesion** and **negative acid-fast bacilli (AFB)** on scrapings. - The 6-month duration is effective in eradicating the infection with high cure rates and low relapse rates. * (Rifampicin + Dapsone) for 12 months* - This 12-month regimen is unnecessarily prolonged for paucibacillary leprosy, increasing the risk of side effects and reducing patient adherence without additional clinical benefit compared to the 6-month regimen. - While Rifampicin and Dapsone are correct drugs for PB leprosy, the duration is not aligned with current WHO guidelines for this specific presentation. * (Rifampicin + Dapsone + Clofazamine) for 6 months* - The addition of **Clofazamine** makes this the regimen for **multibacillary (MB) leprosy**, which presents with multiple skin lesions or positive AFB smears. - This patient's presentation of a **single lesion** and **negative AFB** clearly indicates paucibacillary leprosy, for which Clofazamine is not typically included. * (Rifampicin + Dapsone + Clofazamine) for 12 months* - This is the standard regimen for **multibacillary (MB) leprosy**, due to the presence of Clofazamine and the 12-month duration. - It is not appropriate for a patient with a **single, AFB-negative lesion**, as this presentation denotes paucibacillary leprosy requiring a shorter, two-drug treatment.

Q: Innumerable, small, normoesthetic and symmetrical skin lesions are present in which type of leprosy:

Lepromatous. ***Lepromatous*** - **Lepromatous leprosy** is characterized by a high bacterial load, leading to **innumerable, symmetrical, and poorly defined skin lesions** distributed bilaterally. - In **early lepromatous disease**, lesions may be **normoesthetic** (normal sensation) or only mildly hypesthetic before significant nerve damage develops. However, as the disease progresses, sensory loss becomes more apparent due to diffuse nerve involvement. - The combination of **innumerable + symmetrical + normoesthetic** lesions is most characteristic of **early lepromatous leprosy**. *Tuberculoid* - **Tuberculoid leprosy** typically presents with **few (1-5), well-demarcated, and often asymmetric** skin lesions. - These lesions show **marked sensory loss early** (anesthetic from onset) due to intense localized immune response and nerve damage. - Does not fit the description of innumerable, normoesthetic lesions. *Borderline tuberculoid* - **Borderline tuberculoid leprosy** features a **moderate number of lesions** (more than tuberculoid but not innumerable), which are usually well-defined. - Lesions show **noticeable sensory impairment** relatively early in the disease course. - Does not present with innumerable lesions. *Borderline lepromatous* - **Borderline lepromatous leprosy** has numerous lesions with varied morphology (macules, papules, plaques). - While extensive, sensory loss is usually **more pronounced** than in pure lepromatous leprosy due to more active nerve inflammation. - The combination of normoesthetic + innumerable + symmetrical is more specific to lepromatous rather than borderline lepromatous.

Q: In the management of leprosy, Lepromin test is most useful for:-

Prognosis. Prognosis - A positive Lepromin test indicates a strong cell-mediated immune response to Mycobacterium leprae, which is associated with the tuberculoid form of leprosy and a better prognosis [1]. - A negative test suggests a poor immune response, seen in lepromatous leprosy [1], which is associated with a more severe, disseminated disease and worse prognosis. Epidemiological investigations - While it reflects immune status, the Lepromin test is not primarily used for identifying active cases or tracking disease transmission in the general population. - Its utility in population-level studies is limited as it doesn't distinguish between past exposure, subclinical infection, or present disease. Treatment - The Lepromin test does not guide the choice of specific medications or the duration of multi-drug therapy (MDT) for leprosy. - Treatment regimens are determined by the classification of leprosy (paucibacillary or multibacillary) based on clinical and bacteriological findings. Herd immunity - Herd immunity applies to vaccine-preventable diseases where a high percentage of the population is immune, indirectly protecting susceptible individuals. - Leprosy is not typically controlled through herd immunity, and the Lepromin test does not assess population-level protection.

Q: Incubation period of LGV:

1 month. ***1 month*** - The incubation period for the primary lesion (a small, painless papule or vesicle) in **lymphogranuloma venereum (LGV)** is typically **1-4 weeks**, with 1 month being a common estimate [1]. - This primary lesion often goes unnoticed as it heals rapidly, usually within a few days [1]. *15-45 days* - While technically encompassing the range, **15-45 days** might be seen as slightly broad or less precise than the more common "1 month" estimate for the primary lesion. - The more prominent secondary stage with lymphadenopathy typically develops a few weeks after the primary lesion [1]. *6 months* - An incubation period of **6 months** is far too long for LGV. The disease characteristics usually manifest within weeks. - Such a long incubation period would suggest a different type of infection or a very delayed presentation, which is not characteristic of typical LGV. *3-12 days* - An incubation period of **3-12 days** is too short for LGV. This timeframe is more typical for diseases like **genital herpes** or **chancroid** [1]. - LGV caused by *Chlamydia trachomatis* serovars L1, L2, or L3, generally has a longer incubation before the primary lesion appears.

Q: Secondary syphilis is characterised by all except (choose the MOST appropriate answer)

Gummatous ulcers. ***Gummatous ulcers*** - **Gummas** are characteristic lesions of **tertiary syphilis**, not secondary syphilis. - They are granulomatous lesions that can affect various organs, including skin, bone, and internal organs. *Cutaneous coppery rashes* - **Coppery (or ham-colored)** macular or papular rashes are a hallmark of **secondary syphilis**, commonly appearing on the trunk, palms, and soles [1]. - These rashes are typically non-itchy and can resolve spontaneously without treatment [1]. *Moth - eaten alopecia* - **Patchy, non-scarring alopecia**, often described as "moth-eaten," is a common manifestation of **secondary syphilis** [2]. - It results from diffuse hair loss due to inflammatory infiltrates around hair follicles. *Ivory sequestrum* - **Skeletal gummas** in **tertiary syphilis** can result in bone necrosis, leading to the formation of an **ivory sequestrum**, which is a dead piece of bone. - This is a feature of **tertiary syphilis** and not seen in the secondary stage.

Q: Not a cutaneous manifestation of TB:

Lupus pernio. ***Lupus pernio*** - **Lupus pernio** is characteristic of **sarcoidosis**, not tuberculosis. It typically presents as violaceous, indurated plaques on the face, especially the nose, cheeks, and ears. - Its presence usually indicates chronic and systemic sarcoidosis, differentiating it from tubercular skin manifestations. *Erythema nodosum* - **Erythema nodosum** can be a cutaneous manifestation of tuberculosis, often indicating an underlying immune response to the infection. - It presents as tender, red nodules, typically on the shins, reflecting a delayed hypersensitivity reaction. *Scrofuloderma* - **Scrofuloderma** is a direct cutaneous manifestation of tuberculosis, resulting from the extension of an underlying tuberculous infection (e.g., lymph nodes, bones) to the skin. - It involves painless, purplish nodules or plaques that ulcerate and discharge pus. *Lupus vulgaris* - **Lupus vulgaris** is a chronic and progressive form of cutaneous tuberculosis, characterized by reddish-brown plaques with an "apple-jelly" appearance on diascopy. - This manifestation occurs due to hematogenous or lymphatic spread of **Mycobacterium tuberculosis** to the skin in individuals with moderate immunity.

Question 1

Not a cutaneous manifestation of tuberculosis:

Accepted Answer

Erythema migrans

Answer

Exanthematous lesion

Answer

Scrofuloderma

Answer

Lupus vulgaris

Question 2

A patient has asymptomatic painless burrowing ulcer in the palate. He might be suffering from

Accepted Answer

Syphilis

Answer

Actinomycosis

Answer

Tuberculosis

Answer

Histoplasmosis

Question 3

Painful matted suppurative lymphadenitis after healing of genital lesion is seen in:

Accepted Answer

LGV

Answer

Syphilis

Answer

Donovanosis

Answer

Chancroid

Question 4

Apple jelly nodule on diascopy is a feature of:

Accepted Answer

Lupus vulgaris

Answer

Aspergillosis

Answer

Erysipelas

Answer

Rhinoscleroma

Question 5

A patient was diagnosed to have single skin lesion of Leprosy without any AFB positive bacteria from the scrapings. What should be the treatment of this patient according to latest guidelines?

Accepted Answer

(Rifampicin + Dapsone) for 6 months

Answer

(Rifampicin + Dapsone) for 12 months

Answer

(Rifampicin + Dapsone + Clofazamine) for 6 months

Answer

(Rifampicin + Dapsone + Clofazamine) for 12 months

Question 6

Innumerable, small, normoesthetic and symmetrical skin lesions are present in which type of leprosy:

Accepted Answer

Lepromatous

Answer

Tuberculoid

Answer

Borderline tuberculoid

Answer

Borderline lepromatous

Question 7

In the management of leprosy, Lepromin test is most useful for:-

Accepted Answer

Prognosis

Answer

Epidemiological investigations

Answer

Treatment

Answer

Herd immunity

Question 8

Incubation period of LGV:

Accepted Answer

1 month

Answer

15-45 days

Answer

6 months

Answer

3-12 days

Question 9

Secondary syphilis is characterised by all except (choose the MOST appropriate answer)

Accepted Answer

Gummatous ulcers

Answer

Cutaneous coppery rashes

Answer

Moth - eaten alopecia

Answer

Ivory sequestrum

Question 10

Not a cutaneous manifestation of TB:

Accepted Answer

Lupus pernio

Answer

Erythema nodosum

Answer

Scrofuloderma

Answer

Lupus vulgaris

Bacterial Skin Infections — MCQs

Bacterial Skin Infections — MCQs

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