Bacterial Skin Infections Practice Questions

Q: Which of the following clinical manifestations is LEAST likely in secondary syphilis?

Chancre. ***Chancre*** - A **chancre** is the characteristic lesion of **primary syphilis**, appearing at the site of inoculation [1]. - By the time **secondary syphilis** develops (typically weeks to months later), the chancre of primary syphilis has usually healed spontaneously [1]. *Condylomata lata* - **Condylomata lata** are highly infectious, moist, wart-like lesions that occur in intertriginous areas and mucous membranes during **secondary syphilis** [1]. - They are a common manifestation due to the widespread dissemination of **Treponema pallidum** [1]. *Mucous patches* - **Mucous patches** are painless, white to gray lesions found on mucous membranes (e.g., mouth, pharynx, vagina, anus) during **secondary syphilis**. - These are highly infectious and result from the systemic spread of the spirochete. *Palmar and plantar rash* - A diffuse, non-pruritic, maculopapular rash, often involving the **palms and soles**, is a classic and highly characteristic sign of **secondary syphilis** [1]. - This rash indicates the systemic nature of the infection and can vary widely in appearance [1].

Q: Which lymphogranuloma venereum complication is characterized by fusion of inguinal and femoral lymphadenopathy, separated by Poupart's ligament?

Groove sign. ***Groove sign*** - The **groove sign** is a classic but rare complication seen in **lymphogranuloma venereum (LGV)**, characterized by separation of enlarged inguinal and femoral lymph node groups by the **inguinal ligament (Poupart's ligament)**. - This pathognomonic sign occurs when matted lymph nodes both above and below the inguinal ligament create a groove-like depression, forming the characteristic "groove of Poupart." - Seen in approximately 10-20% of LGV cases with inguinal syndrome. *Bubo* - A **bubo** is a swollen, inflamed lymph node commonly seen in **lymphogranuloma venereum** during the secondary (inguinal) stage. - While LGV causes buboes, the groove sign specifically refers to the anatomical pattern of lymphadenopathy separated by the inguinal ligament, not just any bubo. *Pseudobuboes* - **Pseudobuboes** are subcutaneous granulomatous lesions that mimic lymph node swelling but are not true lymphadenopathy. - These can occur in LGV but represent extension of infection into subcutaneous tissue rather than the specific pattern of inguinal-femoral node separation. *Phagedenic ulceration* - **Phagedenic ulceration** refers to rapidly spreading, destructive ulceration that can occur as a complication of genital ulcer diseases. - While this can occur in severe LGV, it describes the primary lesion progression, not the characteristic lymphadenopathy pattern of the groove sign.

Q: A 38-year-old man with HIV (CD4 count 150/μL) presents with progressive perianal ulceration for 3 months. Multiple biopsies show granulomatous inflammation without organisms. PCR for HSV, dark field microscopy, and serological tests for syphilis are negative. He has received empiric treatment for HSV and syphilis without improvement. What is the most likely diagnosis?

Donovanosis (granuloma inguinale). ***Donovanosis (granuloma inguinale)*** - This diagnosis is strongly suggested by **progressive perianal ulceration** with **granulomatous inflammation** and the exclusion of other common causes, particularly in an immunocompromised patient. - The absence of organisms on routine biopsy, along with negative PCR for HSV and syphilis serology, points towards **Donovanosis**, caused by *Klebsiella granulomatis*, which requires special staining for **Donovan bodies** [1]. *Crohn's disease* - While Crohn's disease can cause perianal ulcerations and granulomas, the **rapid progression** and specific mention of an infectious workup strongly favor an infective etiology in this immunocompromised patient. - Absence of other typical gastrointestinal symptoms like abdominal pain, diarrhea, or weight loss makes Crohn's less likely. *Lymphogranuloma venereum* - Lymphogranuloma venereum (LGV) typically presents with **inguinal lymphadenopathy** (buboes) and initial transient ulcers, rather than progressive perianal ulceration with primary granulomatous inflammation on biopsy [1]. - While it can cause proctitis, the primary presentation described here is less typical for LGV. *Squamous cell carcinoma* - Although immunosuppression increases the risk of squamous cell carcinoma, a "progressive ulceration" with **granulomatous inflammation** described on biopsy is more characteristic of an infectious or inflammatory process than malignancy. - Malignant lesions would typically show **atypical cells** and **dysplasia** on biopsy, which is not mentioned here.

Q: Which of the following genital ulcer diseases is LEAST likely to cause inguinal lymphadenopathy?

Granuloma inguinale. ***Granuloma inguinale*** - While ulcers are present, **granuloma inguinale** typically causes a **painless, progressive ulcerative lesion** and is notable for a lack of significant **lymphadenopathy** [1]. - Systemic manifestations are rare, and regional lymph node involvement, if present, is usually due to **secondary bacterial infection**. *Lymphogranuloma venereum* - Characterized by **painful inguinal lymphadenopathy** (buboes) developing weeks after a transient, often unnoticed, primary ulcer [1]. - The **buboes** can become fluctuant, rupture, and drain, a hallmark feature of the disease. *Chancroid* - Causes **painful genital ulcers** and frequently leads to **tender, unilateral inguinal lymphadenopathy** [1]. - The affected lymph nodes (buboes) can also become suppurative and may rupture. *Genital herpes* - Often presents with painful vesicular lesions that progress to ulcers, accompanied by **tender bilateral inguinal lymphadenopathy** [1], [2]. - The lymphadenopathy is typically more generalized and less likely to suppurate compared to chancroid or LGV.

Q: Which of the following best describes the appearance of a syphilitic chancre?

Painless, clean-based ulcer with indurated edges. ***Painless, clean-based ulcer with indurated edges*** - A **syphilitic chancre** is typically a **painless ulcer**, which is a key diagnostic feature distinguishing it from other genital lesions. - It has a characteristic **clean base** and **firm, raised (indurated) edges** due to the inflammatory infiltrate. *Painful, purulent ulcer with ragged edges* - This description is more indicative of a **chancroid**, caused by *Haemophilus ducreyi*, which presents with **painful, ragged-edged ulcers** that often have a purulent base. - Chancroids typically cause **tender inguinal lymphadenopathy**, unlike the firm, non-tender lymphadenopathy associated with primary syphilis. *Vesicular lesions in clusters* - This appearance is characteristic of **genital herpes**, caused by the **herpes simplex virus (HSV)**. - Herpes lesions begin as painful vesicles that rupture to form ulcers, often recurring in the same area. *Papular lesions with central umbilication* - These lesions are typical of **molluscum contagiosum**, a viral infection. - Molluscum lesions are flesh-colored, dome-shaped papules with a distinctive **central umbilication** or dimple.

Q: A patient with multiple sexual exposures is diagnosed with gonorrhea. What is the appropriate treatment?

Ceftriaxone. ***Ceftriaxone*** - **Ceftriaxone** is the **first-line recommended treatment** for uncomplicated gonorrhea according to **CDC and WHO guidelines**. - Administered as a **single intramuscular injection (500 mg IM)**, it provides highly effective coverage against *Neisseria gonorrhoeae* with minimal resistance. - It works by inhibiting bacterial cell wall synthesis, and is the **gold standard therapy** for gonorrhea treatment. - For patients with multiple sexual exposures, empiric treatment for co-infection with *Chlamydia trachomatis* (doxycycline) should also be considered. *Cefixime* - **Cefixime** was previously used as an oral alternative but is **no longer recommended** as first-line therapy due to **increasing resistance** of *N. gonorrhoeae*. - The CDC removed cefixime from recommended regimens due to **inferior efficacy** compared to ceftriaxone and concerns about treatment failures. - While it is an oral cephalosporin, it is **not appropriate first-line therapy** for gonorrhea. *Doxycycline* - **Doxycycline** is commonly used to treat **co-infection with *Chlamydia trachomatis***, which frequently occurs alongside gonorrhea. - The typical regimen is **100 mg twice daily for 7 days** as adjunctive therapy. - However, doxycycline is **not effective as monotherapy for gonorrhea** and should not be used alone to treat *N. gonorrhoeae* infection. *Acyclovir* - **Acyclovir** is an **antiviral medication** used to treat **herpes simplex virus (HSV)** infections. - It works by inhibiting viral DNA replication and has **no activity against bacterial infections** like gonorrhea. - It would be completely ineffective against *Neisseria gonorrhoeae*.

Q: A 60-year-old person who completed treatment for leprosy many years ago now presents with a punched-out, painless ulcer on the sole of his foot. What is the most appropriate management?

Offloading and comprehensive wound care. ***Offloading and comprehensive wound care*** - **Trophic ulcers** (neuropathic ulcers) in post-leprosy patients are caused by **peripheral neuropathy** and loss of protective sensation, making offloading the cornerstone of management. - **Comprehensive wound care** includes proper dressing, moisture control, and regular monitoring, which are essential for healing in the absence of signs of active infection. *Intense debridement and intravenous antibiotics* - **No signs of infection** are mentioned in the stem (no fever, purulent discharge, or cellulitis), making IV antibiotics inappropriate as first-line treatment. - **Intense debridement** may cause further tissue damage in a clean neuropathic ulcer without evidence of necrosis or infection. *Restart MDT* - The patient has **completed leprosy treatment** years ago, indicating no active **Mycobacterium leprae** infection requiring multidrug therapy. - **Trophic ulcers** are a late complication of **peripheral neuropathy** from leprosy, not active disease requiring antimicrobial treatment. *Amputation* - Amputation is reserved as a **last resort** for cases with severe, uncontrolled infection or extensive tissue necrosis. - **Neuropathic ulcers** can often heal with appropriate **conservative management** including offloading and wound care.

Q: A patient presents with loss of sensation along the ulnar nerve path. The histology is shown in the image, and a Lepromin test was performed. What is the expected outcome?

Borderline tuberculoid (BT) leprosy with lepromin positive. ***Borderline tuberculoid (BT) leprosy with lepromin positive*** - **Peripheral nerve trunk involvement** (ulnar nerve) is characteristic of **BT leprosy**, which shows greater neural involvement than tuberculoid leprosy. - Histology shows **epithelioid cell granulomas** with **sparse lymphocytes**, distinguishing BT from tuberculoid leprosy which has **dense lymphocytic cuffing** around granulomas. *Lepromatous leprosy with lepromin positive* - Lepromatous leprosy shows **foamy macrophages (Virchow cells)** packed with abundant *M. leprae* and **absence of well-formed granulomas**. - Patients are typically **lepromin negative** due to poor **cell-mediated immunity** and anergic immune state. *Tuberculoid leprosy with lepromin positive* - Tuberculoid leprosy shows **dense lymphocytic cuffing** around epithelioid granulomas, unlike the sparse lymphocytes seen in this case. - **Peripheral nerve trunk involvement** is uncommon in tuberculoid leprosy, which typically affects smaller nerve branches. *Scrofuloderma* - **Scrofuloderma** is a form of **cutaneous tuberculosis** from extension of underlying tuberculous lymphadenitis or osteomyelitis. - Does not involve **peripheral nerves** and lacks the specific **Ridley-Jopling spectrum** characteristics of leprosy.

Q: A 25-year-old male presents with a burning sensation during urination and purulent discharge from the penis, which started 5 days ago. He reports unprotected sexual intercourse with a new partner two weeks ago. Examination reveals an erythematous urethral meatus with noticeable purulent discharge. A Gram stain of the discharge reveals intracellular gramnegative diplococci. The patient is otherwise healthy with no known drug allergies. What is the most appropriate treatment for this patient?

Ceftriaxone 500 mg intramuscularly. ***Ceftriaxone 500 mg intramuscularly*** - This patient has **gonococcal urethritis** confirmed by **intracellular gram-negative diplococci** on Gram stain, and **ceftriaxone 500 mg IM** is the **CDC 2021 first-line treatment** for uncomplicated gonorrhea. - Single-dose **intramuscular ceftriaxone** ensures **100% bioavailability** and overcomes concerns about **emerging gonococcal resistance** to oral cephalosporins. *Cefixime 400 mg orally once* - **Cefixime** has been **downgraded to backup-only status** by CDC due to **increasing gonococcal resistance** and treatment failures. - While previously used as first-line therapy, it is now recommended **only when ceftriaxone is unavailable** or contraindicated. *Doxycycline 100 mg orally twice daily for 7 days* - **Doxycycline** is the treatment for **Chlamydia trachomatis** co-infection, which should be considered empirically with gonorrhea treatment. - However, it is **not effective against Neisseria gonorrhoeae** and cannot serve as monotherapy for this patient's primary infection. *Metronidazole 500 mg orally twice daily for 7 days* - **Metronidazole** is effective against **anaerobic bacteria** and **protozoa** like **Trichomonas vaginalis**. - It has **no activity against Neisseria gonorrhoeae** and would be inappropriate for treating gonococcal urethritis.

Q: Kassowitz rule is related to:

Congenital syphilis. ***Congenital syphilis*** - The **Kassowitz rule** specifically describes the high rate of perinatal mortality (abortion, stillbirth, or death shortly after birth) in cases of untreated maternal syphilis, especially during early stages of infection. - It highlights that the risk is highest when the mother acquires syphilis shortly before or during pregnancy, leading to severe fetal disease. *Primary syphilis* - This stage is characterized by a **chancre** at the site of infection and is the initial presentation in the infected individual, not directly related to fetal outcomes. - While primary syphilis in the mother can lead to congenital syphilis, the Kassowitz rule itself describes the outcome of congenital infection, not the primary infection in the mother. *Latent syphilis* - **Latent syphilis** refers to a stage where the infection is present but asymptomatic, potentially for years. - While it can be transmitted vertically and lead to congenital syphilis, the Kassowitz rule specifically quantifies the mortality risk of congenital syphilis, not the mother's latent infection itself. *Secondary syphilis* - This stage involves a systemic rash and other widespread symptoms in the infected individual, appearing weeks to months after the chancre. - Though highly infectious and a significant risk for vertical transmission, the rule focuses on the severe consequences *for the fetus* when congenital syphilis occurs, not the symptoms of secondary syphilis in the mother.

Question 1

Which of the following clinical manifestations is LEAST likely in secondary syphilis?

Accepted Answer

Chancre

Answer

Condylomata lata

Answer

Mucous patches

Answer

Palmar and plantar rash

Question 2

Which lymphogranuloma venereum complication is characterized by fusion of inguinal and femoral lymphadenopathy, separated by Poupart's ligament?

Accepted Answer

Groove sign

Answer

Bubo

Answer

Pseudobuboes

Answer

Phagedenic ulceration

Question 3

A 38-year-old man with HIV (CD4 count 150/μL) presents with progressive perianal ulceration for 3 months. Multiple biopsies show granulomatous inflammation without organisms. PCR for HSV, dark field microscopy, and serological tests for syphilis are negative. He has received empiric treatment for HSV and syphilis without improvement. What is the most likely diagnosis?

Accepted Answer

Donovanosis (granuloma inguinale)

Answer

Crohn's disease

Answer

Lymphogranuloma venereum

Answer

Squamous cell carcinoma

Question 4

Which of the following genital ulcer diseases is LEAST likely to cause inguinal lymphadenopathy?

Accepted Answer

Granuloma inguinale

Answer

Lymphogranuloma venereum

Answer

Chancroid

Answer

Genital herpes

Question 5

Which of the following best describes the appearance of a syphilitic chancre?

Accepted Answer

Painless, clean-based ulcer with indurated edges

Answer

Painful, purulent ulcer with ragged edges

Answer

Vesicular lesions in clusters

Answer

Papular lesions with central umbilication

Question 6

A patient with multiple sexual exposures is diagnosed with gonorrhea. What is the appropriate treatment?

Accepted Answer

Ceftriaxone

Answer

Acyclovir

Answer

Cefixime

Answer

Doxycycline

Question 7

A 60-year-old person who completed treatment for leprosy many years ago now presents with a punched-out, painless ulcer on the sole of his foot. What is the most appropriate management?

Accepted Answer

Offloading and comprehensive wound care

Answer

Restart MDT

Answer

Amputation

Answer

Intense debridement and intravenous antibiotics

Question 8

A patient presents with loss of sensation along the ulnar nerve path. The histology is shown in the image, and a Lepromin test was performed. What is the expected outcome?

Accepted Answer

Borderline tuberculoid (BT) leprosy with lepromin positive

Answer

Tuberculoid leprosy with lepromin positive

Answer

Scrofuloderma

Answer

Lepromatous leprosy with lepromin positive

Question 9

A 25-year-old male presents with a burning sensation during urination and purulent discharge from the penis, which started 5 days ago. He reports unprotected sexual intercourse with a new partner two weeks ago. Examination reveals an erythematous urethral meatus with noticeable purulent discharge. A Gram stain of the discharge reveals intracellular gramnegative diplococci. The patient is otherwise healthy with no known drug allergies. What is the most appropriate treatment for this patient?

Accepted Answer

Ceftriaxone 500 mg intramuscularly

Answer

Metronidazole 500 mg orally twice daily for 7 days

Answer

Doxycycline 100 mg orally twice daily for 7 days

Answer

Cefixime 400 mg orally once

Question 10

Kassowitz rule is related to:

Accepted Answer

Congenital syphilis

Answer

Primary syphilis

Answer

Latent syphilis

Answer

Secondary syphilis

Bacterial Skin Infections — MCQs

Bacterial Skin Infections — MCQs

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