Syphilis — MCQs
A 24-year-old man had been treated for gonorrhea 2 months previously. He developed an ulcerative lesion in the glands of the penis that is noted to be condylomata lata. The etiology of condylomata lata is which of the following?
All of the following are manifestations of congenital syphilis except:-
A patient presents with suspected primary syphilis. Which sequence of tests provides the most cost-effective screening approach?
What is the first-line treatment for syphilis?
What mechanism accounts for the neuroinvasive potential of Treponema pallidum?
A 27-year-old white man presents to his family doctor complaining of being tired all the time and having a slight fever for the past two weeks, following a recent trip to Las Vegas. His physical examination is unremarkable, except for a macular rash over his trunk and on the palms of his hands, with no lesions or ulcers on the penis. What is the causative organism of this man's illness?
Hutchinson's Triad is specifically associated with which type of syphilis?
A 32-year-old HIV-positive man (CD4 count 320/μL) presents with painless perianal ulcer for 3 weeks. Dark field microscopy shows spirochetes. What is the appropriate treatment?
What is the causative agent for the lesion on penis shown below?
Moth-eaten alopecia is seen with:
Syphilis Indian Medical PG Practice Questions and MCQs
Question 1: A 24-year-old man had been treated for gonorrhea 2 months previously. He developed an ulcerative lesion in the glands of the penis that is noted to be condylomata lata. The etiology of condylomata lata is which of the following?
- A. Herpesvirus hominis, type II
- B. Hemophilus ducreyi
- C. Mixture of organisms
- D. Treponema pallidum (Correct Answer)
Explanation: ***Treponema pallidum*** - **Condylomata lata** are characteristic lesions of **secondary syphilis**, caused by *Treponema pallidum* [1]. - They are typically broad, flat, moist, wart-like lesions that occur in warm, moist areas such as the anogenital region [1]. *Herpesvirus hominis, type II* - Herpesvirus hominis, type II (HSV-2) causes **genital herpes**, which manifests as painful vesicles that ulcerate [1]. - The lesions caused by HSV-2 are typically clustered, vesicular, and very painful, which is distinct from the hypertrophic, non-painful nature of condylomata lata [1]. *Hemophilus ducreyi* - *Hemophilus ducreyi* is the causative agent of **chancroid**, which presents as painful, soft ulcers with ragged, undermined borders, often accompanied by painful inguinal lymphadenopathy. - Chancroid lesions are typically destructive and highly painful, contrasting with the proliferative and less painful nature of condylomata lata. *Mixture of organisms* - While some sexually transmitted infections can involve coinfection, **condylomata lata** specifically point to a single etiological agent: *Treponema pallidum* [1]. - Attributing condylomata lata to a "mixture of organisms" is too vague and inaccurate given the specific morphology and strong association with syphilis [1].
Question 2: All of the following are manifestations of congenital syphilis except:-
- A. Olympian brow
- B. Gumma (Correct Answer)
- C. Interstitial keratitis
- D. Hutchinson's teeth
Explanation: ***Gumma*** - **Gumma** is a manifestation of **tertiary syphilis** in adults, typically appearing years after the initial infection [1]. - While syphilis can be transmitted congenitally, **gummatous lesions** are not a characteristic finding in congenital syphilis [1]. *Olympian brow* - **Olympian brow** (also known as frontal bossing) is a feature of **congenital syphilis**, characterized by prominent frontal bones [2]. - It results from **periostitis** and abnormal bone development due to chronic infection in utero. *Interstitial keratitis* - **Interstitial keratitis** is a classic manifestation of **late congenital syphilis**, affecting the cornea [2]. - It presents as **bilateral corneal inflammation** leading to vision impairment, often appearing in childhood or adolescence. *Hutchinson's teeth* - **Hutchinson's teeth** are a pathognomonic sign of **congenital syphilis**, characterized by notched, peg-shaped, and widely spaced incisors. - This dental abnormality results from the treponemal infection disrupting the **enamel formation** during tooth development.
Question 3: A patient presents with suspected primary syphilis. Which sequence of tests provides the most cost-effective screening approach?
- A. Dark field microscopy only
- B. Treponemal test followed by non-treponemal test if positive
- C. Both tests simultaneously
- D. Non-treponemal test followed by treponemal test if positive (Correct Answer)
Explanation: ***Non-treponemal test followed by treponemal test if positive*** - This is the **traditional and most cost-effective screening approach** for suspected syphilis. Non-treponemal tests are inexpensive and good for screening, while treponemal tests confirm positive results [1]. - Initial positive non-treponemal results (e.g., **VDRL, RPR**) indicate active infection or recent treatment and require confirmation with a more specific treponemal test (e.g., **TP-PA, EIA, FTA-ABS**). [1] *Dark field microscopy only* - **Dark field microscopy** is useful for immediate detection of *Treponema pallidum* in primary lesions (chancres) but is **operator-dependent** and not suitable as a general screening tool. - It **lacks sensitivity** for later stages of syphilis or in the absence of an active lesion, making it unreliable for comprehensive screening. *Treponemal test followed by non-treponemal test if positive* - This is known as the **reverse sequence screening algorithm**. While sometimes used, it is generally **less cost-effective** for routine screening due to the higher upfront cost of treponemal tests [1]. - A positive treponemal test can indicate past treated infection, leading to a need for non-treponemal testing to differentiate **active from past infection**, which may lead to unnecessary follow-up for previously treated cases. *Both tests simultaneously* - Performing both tests simultaneously is **more expensive** and less efficient for initial screening than a sequential approach. - While it offers rapid confirmation, it's not the most cost-effective method for widespread screening, especially when considering the potential for discordant results that require further clarification.
Question 4: What is the first-line treatment for syphilis?
- A. Penicillin G (Correct Answer)
- B. Tetracycline
- C. Erythromycin
- D. Rifampicin
Explanation: ***Penicillin G*** - **Penicillin G** is the **drug of choice** for all stages of syphilis due to its high efficacy against *Treponema pallidum*. - Its long duration of action, particularly **benzathine penicillin G**, provides sustained treponemicidal levels for early syphilis and prevents neurosyphilis progression. *Rifampicin* - **Rifampicin** is primarily used in the treatment of **tuberculosis** and other mycobacterial infections. - It has no significant role in the treatment of syphilis and is not effective against *Treponema pallidum*. *Tetracycline* - **Tetracycline** can be used as an **alternative treatment** for syphilis in patients with penicillin allergy. - However, it is not considered first-line due to potential side effects and the need for longer treatment courses compared to penicillin. *Erythromycin* - **Erythromycin** is an older macrolide antibiotic that can be used as an **alternative treatment for early syphilis** in penicillin-allergic pregnant patients. - Its efficacy is less reliable than penicillin G, and it is not recommended for later stages of syphilis or in non-pregnant individuals due to increasing resistance.
Question 5: What mechanism accounts for the neuroinvasive potential of Treponema pallidum?
- A. Perivascular infiltration
- B. Penetration through endothelial tight junctions (Correct Answer)
- C. Transport within infected macrophages
- D. Production of neurotoxins
Explanation: ***Penetration through endothelial tight junctions*** - *Treponema pallidum* has the ability to directly cross the **blood-brain barrier** by disrupting and passing through the tight junctions between endothelial cells. - This direct penetration allows the spirochete to invade the **central nervous system** early in the infection course, leading to neurosyphilis. - This mechanism of paracellular penetration through compromised tight junctions is the primary route of CNS invasion. *Perivascular infiltration* - While **inflammatory cells** may infiltrate the perivascular spaces in neurosyphilis, this is a consequence of the infection rather than the primary mechanism of *T. pallidum*'s entry into the CNS. - Simply infiltrating around blood vessels does not explain how the bacteria traverse the **endothelial barrier**. *Transport within infected macrophages* - Although some pathogens use a "Trojan horse" mechanism by being carried within **macrophages**, there is limited evidence that this is the primary or significant mechanism for *T. pallidum* to cross the **blood-brain barrier**. - The direct invasiveness of *T. pallidum* through endothelial cells is considered the main route. *Production of neurotoxins* - *Treponema pallidum* is not known to produce potent **neurotoxins** that directly cause its neuroinvasive potential or neurological damage, unlike some other bacteria (e.g., *Clostridium botulinum*). - The pathology in neurosyphilis is primarily due to the **inflammatory response** to the presence of the spirochetes within the CNS.
Question 6: A 27-year-old white man presents to his family doctor complaining of being tired all the time and having a slight fever for the past two weeks, following a recent trip to Las Vegas. His physical examination is unremarkable, except for a macular rash over his trunk and on the palms of his hands, with no lesions or ulcers on the penis. What is the causative organism of this man's illness?
- A. Chlamydia trachomatis
- B. Borrelia burgdorferi
- C. Treponema pallidum (Correct Answer)
- D. Neisseria gonorrhoeae
Explanation: ***Treponema pallidum*** - The patient's symptoms, including **fatigue**, **low-grade fever**, and a **macular rash on the trunk and limbs that may later involve the palms and soles** [1], are classic manifestations of **secondary syphilis**, caused by *Treponema pallidum*. - Although there are no genital lesions currently, the rash and systemic symptoms are highly suggestive of disseminated infection following an untreated primary chancre. *Chlamydia trachomatis* - This bacterium is a common cause of **urethritis**, **cervicitis**, and **lymphogranuloma venereum**, but it does not typically cause a diffuse macular rash on the trunk and palms. - While it can cause systemic symptoms in some cases (e.g., reactive arthritis), the described rash is not characteristic. *Neisseria gonorrhoeae* - This organism primarily causes **gonorrhea**, presenting as urethritis with purulent discharge, cervicitis, or pelvic inflammatory disease; it can also cause disseminated gonococcal infection. - Disseminated gonococcal infection can cause rash, but it is typically **pustular or vesiculopustular**, often on extremities, and not the diffuse macular rash described. *Borrelia burgdorferi* - This spirochete is the causative agent of **Lyme disease**, transmitted by ticks. - The classic rash of Lyme disease is **erythema migrans** (a bull's-eye rash), which is distinct from the macular trunk and palm rash seen in this patient.
Question 7: Hutchinson's Triad is specifically associated with which type of syphilis?
- A. Tertiary syphilis
- B. Primary syphilis
- C. Congenital Syphilis (Correct Answer)
- D. Secondary Syphilis
Explanation: ***Congenital Syphilis*** - **Hutchinson's Triad** is a classic constellation of symptoms specific to **congenital syphilis**, reflecting the long-term effects of *in utero* infection [1]. - The triad includes **Hutchinson's teeth** (notched incisors), **interstitial keratitis** (corneal inflammation), and **sensorineural hearing loss**. *Tertiary syphilis* - This stage is characterized by **gummas**, **cardiovascular syphilis** (e.g., aortitis), and **neurosyphilis**, but not Hutchinson's triad [1]. - These manifestations develop years after initial infection in adults. *Primary syphilis* - The primary stage is marked by the appearance of a **painless chancre** at the site of infection [1]. - It does not involve the systemic, long-term complications seen in congenital syphilis. *Secondary Syphilis* - This stage typically presents with a **diffuse maculopapular rash**, **lymphadenopathy**, and sometimes **condylomata lata** [1]. - These are acute systemic symptoms, distinct from the developmental abnormalities of Hutchinson's triad.
Question 8: A 32-year-old HIV-positive man (CD4 count 320/μL) presents with painless perianal ulcer for 3 weeks. Dark field microscopy shows spirochetes. What is the appropriate treatment?
- A. Benzathine penicillin G 2.4 million units IM weekly for 3 weeks
- B. Azithromycin 2g orally single dose
- C. Benzathine penicillin G 2.4 million units IM single dose (Correct Answer)
- D. Doxycycline 100mg orally twice daily for 14 days
Explanation: ***Benzathine penicillin G 2.4 million units IM single dose*** - The presence of a painless perianal ulcer and **spirochetes on dark field microscopy** is highly suggestive of **primary syphilis**. - For primary syphilis, the recommended treatment is a **single intramuscular dose of benzathine penicillin G 2.4 million units**, regardless of HIV status unless there's evidence of neurosyphilis. *Benzathine penicillin G 2.4 million units IM weekly for 3 weeks* - This regimen is typically reserved for **late latent syphilis** or syphilis of unknown duration. - It is not indicated for primary syphilis, which can be cured with a single dose. *Azithromycin 2g orally single dose* - **Azithromycin** is a potential alternative for syphilis in some cases, particularly for penicillin-allergic patients, but it is not the first-line treatment due to increasing rates of macrolide resistance. - The recommended dosage for early syphilis (including primary) is typically **2g orally as a single dose**, but penicillin remains superior. *Doxycycline 100mg orally twice daily for 14 days* - **Doxycycline** is an alternative treatment for early syphilis (primary, secondary, or early latent) in **penicillin-allergic patients**. - The standard duration for early syphilis is **14 days**, but it is not the preferred treatment for patients without penicillin allergy.
Question 9: What is the causative agent for the lesion on penis shown below?
- A. Treponema pallidum (Correct Answer)
- B. HPV
- C. EBV
- D. KSHV
Explanation: ***Treponema pallidum*** * The image displays **condylomata lata**, which are moist, flat-topped, wart-like lesions that occur in secondary syphilis. * These lesions are highly infectious and contain a high concentration of **_Treponema pallidum_**. * _HPV_ * **Human Papillomavirus** causes **condylomata acuminata** (genital warts), which are typically exophytic, raised, and cauliflower-like or filiform, not the flat, broad lesions seen in the image. * While some HPV types are oncogenic, the morphology presented is not characteristic of typical HPV-induced warts. * _EBV_ * **Epstein-Barr virus** is associated with infectious mononucleosis and certain malignancies like nasopharyngeal carcinoma and Burkitt lymphoma, but not with penile lesions of this nature. * There is no direct causal link between typical EBV infection and genital warts or similar proliferative lesions. * _KSHV_ * **Kaposi's Sarcoma-associated Herpesvirus** (KSHV), also known as Human Herpesvirus 8 (HHV-8), causes Kaposi's sarcoma, a vascular tumor. * Kaposi's sarcoma lesions typically appear as **purple, red, or brown macules, plaques, or nodules**, which are distinct from the white/grey, moist, flat lesions shown.
Question 10: Moth-eaten alopecia is seen with:
- A. Cylindroma
- B. Syphilis (Correct Answer)
- C. Fungal infection
- D. Leprosy
Explanation: ***Syphilis*** - **Moth-eaten alopecia** is a characteristic but non-specific finding in **secondary syphilis**, occurring due to immune-mediated inflammation targeting hair follicles. - It presents as patchy, non-scarring hair loss, predominantly on the scalp, eyebrows, and beard area. *Cylindroma* - **Cylindroma** is a benign adnexal tumor of the skin, typically presenting as multiple fleshy nodules on the scalp and face. - It is not associated with hair loss patterns like moth-eaten alopecia; rather, large lesions can cause pressure atrophy of hair follicles leading to localized hair loss. *Fungal infection* - **Fungal infections** of the scalp, such as tinea capitis, typically cause patches of **scaling, erythema, and broken hairs**, sometimes leading to **black dot tinea**. - While they can cause patchy hair loss, the description of "moth-eaten" is not the characteristic presentation for fungal infections. *Leprosy* - **Leprosy** can cause hair loss, particularly loss of the **lateral eyebrows** (madarosis) and body hair. - This hair loss is typically due to nerve damage leading to atrophy of hair follicles or direct granulomatous infiltration, not diffuse patchy "moth-eaten" alopecia.
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