A 25-year-old man presents with painless penile ulcer for 2 weeks. Physical examination reveals a firm, non-tender, clean-based ulcer with rolled edges. Dark-field microscopy of the lesion shows spirochetes. VDRL test is positive at 1:32 dilution. Which of the following is the most appropriate treatment?
Q172
A patient with gonorrhea infection shows persistence of symptoms despite appropriate treatment with Ceftriaxone. Which of the following best explains this treatment failure?
Q173
A 25-year-old male presents with purulent urethral discharge and dysuria for 3 days. Gram stain shows intracellular gram-negative diplococci. What is the most appropriate empirical treatment regimen according to current CDC guidelines?
Q174
A patient presents with suspected primary syphilis. Which sequence of tests provides the most cost-effective screening approach?
Q175
Which diagnostic test is most appropriate for detecting early congenital syphilis?
Q176
What is the most common cause of genital ulcers globally?
Q177
A 24-year-old woman presents with painful genital ulcers and lymphadenopathy. Tzanck smear shows multinucleated giant cells. What is the most appropriate initial treatment?
Q178
A 25-year-old man presents with multiple painful genital ulcers with undermined edges and suppurative lymphadenopathy. Gram stain shows 'school of fish' arrangement. What is the most appropriate initial treatment?
Q179
Which serological test for syphilis remains positive even after successful treatment?
Q180
A 19-year-old university student presents to the student clinic with painful joints. He states that over the past week his right wrist has become increasingly stiff. This morning he noticed pain and stiffness in his left ankle and left knee. The patient has celiac disease and takes a daily multivitamin. He says he is sexually active with multiple male and female partners. He smokes marijuana but denies intravenous drug abuse. He recently traveled to Uganda to volunteer at a clinic that specialized in treating patients with human immunodeficiency virus (HIV). He also went on an extended hiking trip last week in New Hampshire. Physical exam reveals swelling of the right wrist and a warm, swollen, erythematous left knee. The left Achilles tendon is tender to palpation. There are also multiple vesicopustular lesions on the dorsum of the right hand. No penile discharge is appreciated. Arthrocentesis of the left knee is performed. Synovial fluid results are shown below:
Synovial fluid:
Appearance: Cloudy
Leukocyte count: 40,000/mm^3 with neutrophil predominance
Gram stain is negative. A synovial fluid culture is pending. Which of the following is the patient’s most likely diagnosis?
Venerology Indian Medical PG Practice Questions and MCQs
Question 171: A 25-year-old man presents with painless penile ulcer for 2 weeks. Physical examination reveals a firm, non-tender, clean-based ulcer with rolled edges. Dark-field microscopy of the lesion shows spirochetes. VDRL test is positive at 1:32 dilution. Which of the following is the most appropriate treatment?
A. Azithromycin 1g orally single dose
B. Three weekly doses of benzathine penicillin G 2.4 million units IM
C. Single dose of benzathine penicillin G 2.4 million units IM (Correct Answer)
D. Doxycycline 100 mg orally twice daily for 14 days
E. Ceftriaxone 250 mg IM single dose
Explanation: ***Single dose of benzathine penicillin G 2.4 million units IM***
- This is the recommended treatment for **primary syphilis**, characterized by a **painless chancre** and **positive dark-field microscopy** and VDRL [1].
- The single dose is effective because primary syphilis is an early stage of the infection [1].
*Azithromycin 1g orally single dose*
- This regimen is primarily used for the treatment of **Chlamydia trachomatis** infections.
- It is not effective against **Treponema pallidum**, the causative agent of syphilis.
*Three weekly doses of benzathine penicillin G 2.4 million units IM*
- This multi-dose regimen is indicated for **late latent syphilis** or **syphilis of unknown duration**, not primary syphilis.
- While penicillin is the correct drug, the duration of therapy is too long for an early-stage infection.
*Doxycycline 100 mg orally twice daily for 14 days*
- Doxycycline is an alternative treatment for **early syphilis** (primary, secondary, or early latent) in patients who are allergic to penicillin.
- Given that penicillin is not contraindicated here, it is not the primary choice, and treatment with penicillin is more effective.
*Ceftriaxone 250 mg IM single dose*
- Ceftriaxone is a treatment for **gonorrhea**, not syphilis.
- While it has some activity against *Treponema pallidum*, it is not the recommended first-line treatment for syphilis.
Question 172: A patient with gonorrhea infection shows persistence of symptoms despite appropriate treatment with Ceftriaxone. Which of the following best explains this treatment failure?
A. Reinfection from untreated partner (Correct Answer)
B. Host immune deficiency
C. Initial misdiagnosis
D. Development of new resistance during therapy
Explanation: ***Reinfection from untreated partner***
- The most common reason for persistent gonorrhea symptoms despite appropriate treatment is **re-exposure** to the infection from an **untreated sexual partner** [1].
- This highlights the importance of **partner notification and treatment** in managing sexually transmitted infections [1].
*Host immune deficiency*
- While host immune status can influence the severity or recurrence of infections, a primary **immune deficiency** is a less common explanation for treatment failure of uncomplicated gonorrhea, especially with an effective antibiotic like ceftriaxone.
- Gonorrhea is typically managed effectively with standard antibiotic regimens, even in individuals with common viral infections like HIV, unless there are severe, unmanaged coinfections or systemic immunosuppression.
*Initial misdiagnosis*
- An initial misdiagnosis could lead to persistent symptoms if the patient never had gonorrhea or had another co-infection that was not treated. However, the question states "gonorrhea infection" and "appropriate treatment with Ceftriaxone," implying the diagnosis was correct and the treatment regimen was standard.
- This option does not explain why the **specific treatment for gonorrhea** failed, but rather suggests a fundamental error in the diagnostic process.
*Development of new resistance during therapy*
- Although **antibiotic resistance** in *Neisseria gonorrhoeae* is a growing concern, the development of *new* resistance mutations *during* a typical short course of effective ceftriaxone treatment for an initial infection is rare [1].
- More commonly, resistance profiles are established before treatment, or an existing resistant strain was acquired, rather than a new mutation arising and causing failure within the short therapeutic window.
Question 173: A 25-year-old male presents with purulent urethral discharge and dysuria for 3 days. Gram stain shows intracellular gram-negative diplococci. What is the most appropriate empirical treatment regimen according to current CDC guidelines?
A. Ceftriaxone 500mg IM single dose + Azithromycin 1g oral single dose (Correct Answer)
B. Azithromycin 2g oral single dose
C. Doxycycline 100mg oral twice daily for 7 days
D. Ceftriaxone 1g IM single dose
Explanation: ***Ceftriaxone 500mg IM single dose + Azithromycin 1g oral single dose***
- This regimen is the recommended empirical treatment for **uncomplicated gonococcal infections** according to current CDC guidelines, covering both *N. gonorrhoeae* and potential co-infection with *C. trachomatis*. [1]
- The **intracellular gram-negative diplococci** on Gram stain are highly suggestive of **Neisseria gonorrhoeae**, and the addition of azithromycin addresses potential **chlamydial co-infection**. [1]
*Azithromycin 2g oral single dose*
- While azithromycin is used to treat **Chlamydia**, a 2g dose alone as monotherapy is not recommended for suspected gonococcal urethritis due to increased **resistance concerns** and lack of optimal efficacy against *N. gonorrhoeae*.
- This regimen would not adequately cover **gonorrhea**, especially given the evidence of gram-negative diplococci.
*Doxycycline 100mg oral twice daily for 7 days*
- Doxycycline is the primary treatment for **chlamydial infections**, but it is **not effective** as monotherapy for **gonorrhea**.
- Using doxycycline alone for suspected gonococcal urethritis would result in **treatment failure** for the likely gonococcal infection.
*Ceftriaxone 1g IM single dose*
- **Ceftriaxone** is the cornerstone of gonorrhea treatment, but the recommended dose for uncomplicated infection is **500mg IM**. [1] A 1g dose is typically reserved for severe or disseminated cases.
- More importantly, **monotherapy with ceftriaxone** is generally not recommended due to the high prevalence of **chlamydial co-infection**, which would not be treated with ceftriaxone alone.
Question 174: 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 175: Which diagnostic test is most appropriate for detecting early congenital syphilis?
A. VDRL
B. IgM testing (Correct Answer)
C. TPHA
D. Dark field microscopy
Explanation: ***IgM testing***
- **IgM antibodies** are the first antibodies produced in response to a **Treponema pallidum infection** and do not cross the placenta, making them specific for actual fetal infection. [1]
- A positive IgM test in a neonate indicates a **recent or active infection**, differentiating it from passively acquired maternal IgG antibodies. [1]
*VDRL*
- The **VDRL test** (Venereal Disease Research Laboratory) detects **non-treponemal antibodies** and can be used in newborns, but it may also be positive due to passive transfer of maternal antibodies, leading to false positives. [1]
- While useful for screening, it doesn't definitively distinguish between passive maternal transfer and active congenital infection without additional follow-up or comparison to maternal titers.
*TPHA*
- **TPHA** (Treponema Pallidum Hemagglutination Assay) detects **treponemal antibodies**, which are highly specific for syphilis but also cross the placenta.
- A positive TPHA in a neonate could simply reflect the mother's previous exposure to syphilis rather than an active fetal infection.
*Dark field microscopy*
- **Dark field microscopy** directly visualizes **Treponema pallidum spirochetes** from lesions or body fluids, but it requires accessible lesions (which might not be present at birth or in early stages) and skilled personnel.
- It's not a general screening test for early congenital syphilis but rather a diagnostic tool for active lesions in symptomatic cases.
Question 176: What is the most common cause of genital ulcers globally?
A. Chlamydia trachomatis
B. Treponema pallidum
C. Herpes simplex virus (Correct Answer)
D. Haemophilus ducreyi
Explanation: ***Herpes simplex virus***
- **HSV-2** (primarily) and **HSV-1** are the leading causes of **genital ulcers** worldwide, characterized by painful vesicles that rupture and form ulcers.
- Its high prevalence and recurrent nature make it the most common etiological agent for genital ulcer disease.
*Chlamydia trachomatis*
- While *Chlamydia trachomatis* is the most common bacterial sexually transmitted infection, it typically causes **urethritis** or **cervicitis**, not genital ulcers.
- Certain serovars (L1, L2, L3) can cause **lymphogranuloma venereum (LGV)**, which involves lymphadenopathy and sometimes ulcers, but is less common globally.
*Treponema pallidum*
- *Treponema pallidum* causes **syphilis**, which presents with a characteristic **painless chancre** (a type of ulcer).
- Although significant, syphilis is not as prevalent globally as HSV as a cause of genital ulcers.
*Haemophilus ducreyi*
- *Haemophilus ducreyi* is the causative agent of **chancroid**, which is characterized by **painful, friable genital ulcers** with ragged borders.
- While common in some regions, its global incidence is lower than that of herpes simplex virus.
Question 177: A 24-year-old woman presents with painful genital ulcers and lymphadenopathy. Tzanck smear shows multinucleated giant cells. What is the most appropriate initial treatment?
A. Acyclovir 400mg TID for 7-10 days
B. Acyclovir 200mg 5 times daily for 7-10 days
C. Famciclovir 250mg TID for 7-10 days
D. Valacyclovir 1g BD for 7-10 days (Correct Answer)
Explanation: ***Valacyclovir 1g BD for 7-10 days***
- This is the recommended initial treatment for **genital herpes simplex virus (HSV)** infections, especially for the **first clinical episode**. [1]
- Valacyclovir offers a more convenient twice-daily dosing compared to acyclovir due to its **better bioavailability**.
*Acyclovir 400mg TID for 7-10 days*
- This regimen is often used for **suppressive therapy** or less severe recurrent outbreaks of genital herpes, not typically for initial severe presentations.
- While acyclovir is effective, higher doses or more frequent dosing are usually recommended for the initial episode's acute treatment.
*Acyclovir 200mg 5 times daily for 7-10 days*
- This is an appropriate initial treatment regimen for the **first clinical episode of genital herpes**. [1]
- However, valacyclovir offers better patient adherence due to less frequent dosing without compromising efficacy.
*Famciclovir 250mg TID for 7-10 days*
- Famciclovir is an effective antiviral for genital herpes, but the recommended dose for an initial episode is typically higher (e.g., 250 mg three times a day for 7-10 days or 500 mg twice a day for 7 days). [1]
- Like valacyclovir, it's a prodrug of penciclovir, but valacyclovir generally has a more preferred dosing schedule for convenience.
Question 178: A 25-year-old man presents with multiple painful genital ulcers with undermined edges and suppurative lymphadenopathy. Gram stain shows 'school of fish' arrangement. What is the most appropriate initial treatment?
A. Erythromycin 500mg QID for 7 days
B. Azithromycin 1g single dose (Correct Answer)
C. Ceftriaxone 250mg IM single dose
D. Doxycycline 100mg BD for 7 days
Explanation: ***Azithromycin 1g single dose***
- This presentation is highly suggestive of **chancroid**, caused by *Haemophilus ducreyi*. **Azithromycin 1g single dose** is a highly effective and convenient treatment as recommended by CDC guidelines.
- The **"school of fish"** gram stain appearance and **painful genital ulcers with undermined edges** are classic features of chancroid [1], making azithromycin the most appropriate initial therapy.
*Erythromycin 500mg QID for 7 days*
- While **erythromycin** is an effective treatment for chancroid, the **multi-day regimen** makes it less convenient and potentially lowers adherence compared to a single-dose option.
- This regimen is less preferred as a first-line initial treatment given the availability of single-dose options for chancroid.
*Ceftriaxone 250mg IM single dose*
- **Ceftriaxone IM** is the preferred treatment for uncomplicated **gonorrhea** and is also used for **syphilis**, but it is **not the primary treatment for chancroid**.
- While it has some activity against *Haemophilus ducreyi*, azithromycin or ciprofloxacin are generally more effective and recommended for chancroid.
*Doxycycline 100mg BD for 7 days*
- **Doxycycline** is the treatment of choice for **chlamydia** and **syphilis**, but it is **not the recommended first-line treatment for chancroid**.
- Its efficacy against *Haemophilus ducreyi* is not as reliable as macrolides or fluoroquinolones for chancroid.
Question 179: Which serological test for syphilis remains positive even after successful treatment?
A. VDRL
B. RPR
C. TPHA (Correct Answer)
D. FTA-ABS Quantitative
Explanation: ***TPHA***
- **Treponemal tests** like TPHA detect antibodies specifically against *Treponema pallidum* and typically remain **positive indefinitely** after infection, regardless of successful treatment.
- A positive TPHA indicates past or present infection and is not used to monitor treatment efficacy [1].
*VDRL*
- **Non-treponemal tests** like VDRL measure antibodies to cardiolipin, a lipid released during tissue damage from syphilis.
- VDRL titers usually **decrease significantly** and often become negative after successful treatment for syphilis [1].
*RPR*
- **Non-treponemal tests** like RPR also measure antibodies to cardiolipin and are used for **screening and monitoring treatment response** [1].
- RPR titers are expected to **decline after successful therapy**, and a sustained high titer suggests treatment failure or re-infection.
*FTA-ABS Quantitative*
- The **FTA-ABS** (Fluorescent Treponemal Antibody Absorption) test is a **treponemal test** that detects specific antibodies to *Treponema pallidum*.
- While typically remaining positive for life, it is primarily a qualitative test, and a "quantitative" version is not the standard for monitoring treatment or distinguishing active from past infection.
Question 180: A 19-year-old university student presents to the student clinic with painful joints. He states that over the past week his right wrist has become increasingly stiff. This morning he noticed pain and stiffness in his left ankle and left knee. The patient has celiac disease and takes a daily multivitamin. He says he is sexually active with multiple male and female partners. He smokes marijuana but denies intravenous drug abuse. He recently traveled to Uganda to volunteer at a clinic that specialized in treating patients with human immunodeficiency virus (HIV). He also went on an extended hiking trip last week in New Hampshire. Physical exam reveals swelling of the right wrist and a warm, swollen, erythematous left knee. The left Achilles tendon is tender to palpation. There are also multiple vesicopustular lesions on the dorsum of the right hand. No penile discharge is appreciated. Arthrocentesis of the left knee is performed. Synovial fluid results are shown below:
Synovial fluid:
Appearance: Cloudy
Leukocyte count: 40,000/mm^3 with neutrophil predominance
Gram stain is negative. A synovial fluid culture is pending. Which of the following is the patient’s most likely diagnosis?
A. Lyme disease
B. Disseminated gonococcal infection (Correct Answer)
C. Dermatitis herpetiformis
D. Reactive arthritis
E. Septic arthritis
Explanation: ### Disseminated gonococcal infection
- The patient's presentation with **migratory polyarthralgia**, tenosynovitis (tender Achilles tendon), and **vesicopustular skin lesions** in a sexually active individual strongly suggests disseminated gonococcal infection.
- The synovial fluid showing **leukocyte count of 40,000/mm^3** with neutrophil predominance and a negative Gram stain is consistent with a non-septic (culture-negative) arthritis, which is common in disseminated gonococcal infection.
*Lyme disease*
- While Lyme disease can cause migratory arthralgia, it typically presents with an **erythema chronicum migrans rash** and is less commonly associated with vesicopustular lesions or tenosynovitis of the Achilles tendon.
- The high synovial fluid leukocyte count and pustular rash are less typical for early Lyme arthritis.
*Dermatitis herpetiformis*
- This is a cutaneous manifestation of **celiac disease**, characterized by intensely pruritic papules and vesicles, primarily on extensor surfaces.
- It does **not typically cause joint pain** or the acute inflammatory arthritis seen in this patient.
*Reactive arthritis*
- Reactive arthritis can cause oligoarthritis and enthesitis (like Achilles tendonitis), often following a genitourinary or gastrointestinal infection [1].
- However, it is **not typically associated with vesicopustular skin lesions**, and the migratory pattern with prominent tenosynovitis points away from this diagnosis.
*Septic arthritis*
- While the synovial fluid leukocyte count is high and consistent with infection, the **negative Gram stain** and the presence of **multiple pustular skin lesions** make a diagnosis of disseminated gonococcal infection more likely compared to typical septic arthritis from other bacteria [2].
- Disseminated gonococcal infection often presents as a _septic arthritis without pus_ or a _polyarthralgia-dermatitis syndrome_, where cultures may be negative.
