Bacterial Skin Infections Practice Questions

Q: Leonine facies is seen in which type of leprosy?

Lepromatous. **Explanation:** **Leonine facies** (lion-like appearance) is a classic clinical hallmark of **Lepromatous Leprosy (LL)**. This occurs due to the hematogenous spread of *Mycobacterium leprae* in a host with low cell-mediated immunity (CMI). The high bacterial load leads to diffuse infiltration of the facial skin, resulting in: * Thickening and furrowing of the forehead and cheeks. * Widening of the nose. * Pendulous earlobes. * Loss of eyebrows (Madarosis), particularly the lateral one-third. **Analysis of Options:** * **Tuberculoid (TT):** Characterized by high CMI and few lesions (paucibacillary). Lesions are well-defined, anesthetic, and do not cause diffuse facial infiltration. * **Borderline Tuberculoid (BT):** Similar to TT but with more lesions and more nerve involvement; it does not present with the massive infiltration seen in LL. * **Borderline (BB):** An unstable form of leprosy that acts as a transition point. While it has more lesions than TT, it lacks the characteristic diffuse infiltration required to produce leonine facies. **High-Yield Clinical Pearls for NEET-PG:** * **Grenz Zone:** A clear sub-epidermal zone seen on histopathology in Lepromatous Leprosy (absent in TT). * **Globi:** Large clusters of acid-fast bacilli (AFB) found within **Virchow cells** (foamy macrophages) in LL. * **Bacteriological Index (BI):** Highest in LL (4+ to 6+), whereas it is 0 in TT. * **Differential Diagnosis:** Leonine facies can also be seen in **Post-Kala-azar Dermal Leishmaniasis (PKDL)**, Mycosis Fungoides (Cutaneous T-cell Lymphoma), and Sarcoidosis.

Q: An 8-year-old boy presents with a 6-month history of an ill-defined, hypopigmented, slightly atrophic macule on the face. What is the most likely diagnosis?

Indeterminate leprosy. ### Explanation The correct diagnosis is **Indeterminate Leprosy**. In the context of the NEET-PG exam, a solitary, ill-defined, hypopigmented macule in a child—especially when associated with **atrophy** or **sensory loss**—should be considered leprosy until proven otherwise. **Why Indeterminate Leprosy is correct:** Indeterminate leprosy is the earliest clinical stage of leprosy. It typically presents as a single, vaguely defined, hypopigmented macule. While sensory loss may be subtle or absent in early stages, the presence of **atrophy** (thinning of the skin) is a strong clinical pointer toward leprosy rather than simple inflammatory conditions. In endemic regions like India, any persistent hypopigmented patch in a child warrants a high index of suspicion for leprosy. **Why other options are incorrect:** * **Pityriasis alba:** This is a very common cause of hypopigmentation in children (often associated with atopy). However, the patches are usually multiple, have fine scaling (furfuraceous), and **never show atrophy** or sensory loss. * **Morphoea (Localized Scleroderma):** While morphoea can cause atrophy, it typically presents with an initial inflammatory "lilac border" followed by **induration (hardening)** of the skin, rather than just a simple hypopigmented macule. * **Calcium deficiency:** This is a common **myth**. Nutritional deficiencies do not cause localized, well-demarcated hypopigmented patches on the face. **Clinical Pearls for NEET-PG:** * **Earliest sign of Leprosy:** Indeterminate leprosy (often self-healing or progresses to other poles). * **Most common site for Indeterminate Leprosy:** Face in children; outer aspect of thighs/arms in adults. * **Histopathology:** Shows non-specific perineural lymphocytic infiltration (AFB is usually negative). * **Differential Diagnosis Tip:** If the patch is anesthetic, it’s Leprosy; if it scales, it’s likely Pityriasis alba or Tinea versicolor.

Q: A diabetic male presents with a red, tender, and painful swelling on the right buttock with multiple discharging points. The swelling is hard and indurated, accompanied by high-grade fever and malaise. What is the most likely diagnosis?

Carbuncle. ### Explanation The correct diagnosis is **Carbuncle**. **1. Why Carbuncle is correct:** A carbuncle is a deep-seated, inflammatory mass formed by a cluster of interconnecting furuncles. The hallmark clinical feature described—**multiple discharging points** (often likened to a "sieve-like" appearance)—is pathognomonic. It typically occurs in areas with thick skin like the nape of the neck or buttocks. The patient’s profile (diabetic male) is a classic risk factor, as immunocompromised states predispose individuals to deeper, more severe staphylococcal infections. The presence of systemic symptoms like high-grade fever and malaise further points toward this deeper, more extensive infection compared to localized folliculitis. **2. Why other options are incorrect:** * **Folliculitis:** This is a superficial inflammation of the hair follicle. It presents as small, itchy pustules without significant induration or systemic symptoms. * **Furuncle (Boil):** This is a deep-seated infection of a *single* hair follicle. While painful and tender, it presents with a single pointing head, not multiple discharging sinuses. * **Impetigo:** A superficial bacterial infection (usually *S. aureus* or *S. pyogenes*). It presents as honey-colored crusts (non-bullous) or fragile blisters (bullous), typically in children, and lacks deep induration or multiple drainage points. **3. Clinical Pearls for NEET-PG:** * **Etiology:** Most common causative organism is *Staphylococcus aureus*. * **Classic Sign:** The **"Sieve-like" appearance** due to multiple follicular openings discharging pus. * **Predisposing Factors:** Diabetes Mellitus (most common), malnutrition, and immunosuppression. * **Treatment:** Requires systemic antibiotics (e.g., Cloxacillin or Cephalosporins) and often surgical incision and drainage. * **Differential:** Always rule out Hidradenitis Suppurativa if lesions are recurrent in axillary or inguinal regions.

Q: A 38-year-old male presents with swelling in the inguinal region. On examination, inguinal nodes are enlarged along with multiple discharging sinuses from the enlarged lymph nodes. What is the most probable diagnosis?

Lymphogranuloma venereum (LGV). ### Explanation **1. Why Lymphogranuloma Venereum (LGV) is correct:** LGV is caused by **Chlamydia trachomatis (serotypes L1, L2, L3)**. The clinical hallmark of the secondary stage is the **inguinal syndrome**. This involves painful, unilateral or bilateral inguinal lymphadenopathy (buboes). A pathognomonic feature is the **"Groove sign,"** where the inguinal ligament divides the matted nodes. If left untreated, these buboes undergo suppuration and form **multiple discharging sinuses**, as seen in this patient [1]. **2. Why other options are incorrect:** * **Chancroid (*Haemophilus ducreyi*):** Presents with a painful, "soft" ulcer and painful inguinal lymphadenopathy. While buboes can rupture, they typically form a **single** large discharging sinus rather than multiple chronic sinuses [1]. * **Syphilis (*Treponema pallidum*):** Primary syphilis presents with a **painless** hard chancre [2]. The associated lymphadenopathy is typically bilateral, painless, firm, and "shotty," without suppuration or sinus formation. * **Granuloma Inguinale (Donovanosis):** Caused by *Klebsiella granulomatis*. It is characterized by painless, beefy-red, vascular ulcers. It involves "pseudobuboes" (subcutaneous granulation tissue) rather than true lymphadenopathy, and sinuses are not a feature [1]. **3. NEET-PG High-Yield Pearls:** * **Groove Sign:** Pathognomonic for LGV (produced by the inguinal ligament). * **Esthiomene:** Chronic lymphatic obstruction in females leading to vulvar elephantiasis (late-stage LGV). * **Diagnosis:** Nucleic Acid Amplification Test (NAAT) is the preferred method. * **Drug of Choice:** **Doxycycline** (100 mg BID for 21 days). Erythromycin is the alternative for pregnant patients. * **Donovan Bodies:** Safety-pin appearance in tissue smears, diagnostic for Granuloma Inguinale.

Q: A 22-year-old college student with a history of sexual exposure with a commercial sex worker presents with painful genital lesions and lymphadenopathy in the right inguinal region. What is the diagnosis?

Chancroid. **Explanation:** The clinical presentation of **painful genital ulcers** associated with **painful inguinal lymphadenopathy** (buboes) is classic for **Chancroid**, caused by the gram-negative coccobacillus *Haemophilus ducreyi*. **1. Why Chancroid is correct:** The hallmark of Chancroid is the "Painful" ulcer (mnemonic: "Do cry" for *ducreyi*). Unlike other STIs, the lesions are typically soft, ragged, and exquisitely tender. The associated lymphadenopathy is usually unilateral, painful, and may progress to a fluctuant bubo that can rupture. **2. Why other options are incorrect:** * **Syphilis (Primary):** Characterized by a **painless**, indurated (hard) ulcer called a Chancre. The associated lymphadenopathy is also typically painless and bilateral. * **Lymphogranuloma venereum (LGV):** Caused by *Chlamydia trachomatis* (L1-L3). While it features significant inguinal lymphadenopathy (the "Groove sign"), the initial genital ulcer is small, **painless**, and often heals before the patient seeks medical attention. * **Gonorrhea:** Primarily presents as urethritis with purulent discharge rather than discrete genital ulcers. **3. High-Yield Clinical Pearls for NEET-PG:** * **Microscopy:** *H. ducreyi* shows a characteristic **"School of fish"** or "Railroad track" appearance on Gram stain. * **Culture:** Requires enriched media like **Mueller-Hinton agar** with vancomycin or Chocolate agar. * **Treatment:** A single dose of Azithromycin (1g) or Ceftriaxone (250mg IM). * **Differential Diagnosis Tip:** If the ulcer is painful and vesicular/grouped, think Herpes Simplex (HSV); if painful and non-vesicular, think Chancroid.

Q: Pseudo Bubo is seen in which of the following conditions?

Granuloma inguinale (Donovanosis). The correct answer is **Granuloma inguinale (Donovanosis)**. **1. Why Granuloma Inguinale is correct:** In Granuloma inguinale, caused by *Klebsiella granulomatis*, the infection typically presents as painless, beefy-red, highly vascular ulcers. Unlike other sexually transmitted infections, it does **not** involve true regional lymphadenopathy. Instead, it causes subcutaneous inflammatory nodules or granulation tissue in the inguinal region that mimic the appearance of an enlarged lymph node (bubo). Because this swelling is due to subcutaneous involvement rather than actual lymph node enlargement, it is termed a **"Pseudo Bubo."** [1] **2. Why other options are incorrect:** * **Chancroid:** Caused by *Haemophilus ducreyi*, it presents with painful ulcers and **true buboes** (suppurative lymphadenopathy) that are often unilateral and may rupture. [1] * **Lymphogranuloma venereum (LGV):** Caused by *Chlamydia trachomatis* (L1-L3), it is characterized by significant **true lymphadenopathy**. It often presents with the "Groove sign," where the inguinal ligament divides the matted lymph nodes. [1] * **Syphilis:** Primary syphilis presents with a painless chancre and firm, non-suppurative, painless **true regional lymphadenopathy**. **Clinical Pearls for NEET-PG:** * **Donovan Bodies:** Diagnosis of Granuloma inguinale is confirmed by seeing "safety-pin" shaped organisms within macrophages on a Giemsa or Wright stain. * **Beefy Red Ulcer:** A classic descriptor for Donovanosis; these ulcers bleed easily on touch. * **Treatment:** Azithromycin (1g weekly or 500mg daily) is the first-line treatment for Granuloma inguinale. * **Groove Sign:** Pathognomonic for LGV, not Pseudo Bubo.

Q: Which of the following is NOT a primary site of acute gonococcal infection?

Ectocervix. The primary sites of acute gonococcal infection are determined by the type of epithelium present. *Neisseria gonorrhoeae* has a strong predilection for **columnar and transitional epithelium**, while it is resistant to the stratified squamous epithelium found in the adult vagina and ectocervix. **Why Ectocervix is the Correct Answer:** In adult females, the **endocervix** (lined by columnar epithelium) is the most common primary site of infection. The **ectocervix**, however, is covered by **stratified squamous epithelium**, which is resistant to gonococcal invasion. Therefore, it is not a primary site of infection. **Analysis of Other Options:** * **Urethra (A):** Lined by transitional and columnar epithelium, it is the most common site of infection in men and a frequent site in women. * **Bartholin's Glands (B):** These are located in the posterior third of the labia majora. Their ducts are lined by columnar epithelium, making them a common site for acute gonococcal abscess formation. * **Skene's Glands (C):** Also known as paraurethral glands, these are lined by columnar epithelium and are frequently involved in female gonococcal infections. **Clinical Pearls for NEET-PG:** * **Primary Sites in Females:** Endocervix (most common), Urethra, Skene’s glands, and Bartholin’s glands. * **Vulvovaginitis:** While adults are resistant due to squamous epithelium, **pre-pubertal girls** can develop gonococcal vulvovaginitis because their vaginal mucosa is thin and has not yet undergone squamous cornification (due to low estrogen). * **Gold Standard Diagnosis:** Culture on **Thayer-Martin medium** (a selective Chocolate agar). * **Treatment:** Due to rising resistance, the current CDC/WHO recommendation is typically a single dose of **Ceftriaxone (IM)** [1]. Always screen for co-infection with *Chlamydia trachomatis*.

Q: A 48-year-old male presents with a three-month history of non-itchy, generalized papulo-nodular lesions. Physical examination reveals no other abnormalities. Slit smear from a nodule is negative for acid-fast bacilli (AFB). Blood VDRL is reactive at a 1:2 dilution. What is the most likely diagnosis?

Secondary syphilis. **Explanation:** The clinical presentation of generalized, non-itchy papulo-nodular lesions in an adult, combined with a reactive VDRL, is classic for **Secondary Syphilis**. Known as the "Great Imitator," secondary syphilis typically presents with a polymorphic rash (macular, papular, or nodular) that characteristically involves the palms and soles. A VDRL titer of 1:2, while low, is significant in the context of suggestive clinical lesions. **Why the other options are incorrect:** * **Lepromatous Leprosy:** While it presents with generalized nodules, the **negative slit skin smear (SSS)** for Acid-Fast Bacilli (AFB) effectively rules this out, as lepromatous leprosy (multibacillary) would show a high bacterial index. * **Post Kala-Azar Dermal Leishmaniasis (PKDL):** This typically presents with hypopigmented macules, malar erythema, or nodules following an episode of Visceral Leishmaniasis. It would not cause a reactive VDRL. * **Drug Eruption:** These are usually acute in onset, often pruritic (itchy), and temporally related to drug intake. They do not explain the reactive syphilis serology. **High-Yield Clinical Pearls for NEET-PG:** * **Secondary Syphilis:** Always look for involvement of palms and soles, generalized lymphadenopathy (epitrochlear), and "moth-eaten" alopecia. * **Prozone Phenomenon:** In secondary syphilis, very high antibody titers can sometimes cause a false-negative VDRL result; the serum must be diluted to get a positive result. * **VDRL vs. TPHA:** VDRL is a non-specific screening test (titer reflects disease activity), while TPHA/FTA-ABS are specific treponemal tests that remain positive for life.

Question 1

What is the recommended treatment for latent syphilis?

Accepted Answer

Penicillin

Answer

Erythromycin

Answer

Tetracycline

Answer

Ciprofloxacin

Question 2

Leonine facies is seen in which type of leprosy?

Accepted Answer

Lepromatous

Answer

Tuberculoid

Answer

Borderline

Answer

Borderline tuberculoid

Question 3

Which of the following is NOT true regarding Jarisch-Herxheimer reaction?

Accepted Answer

Ophthalmic involvement is typically worsened.

Answer

It occurs in late syphilis.

Answer

It is an acute febrile reaction.

Answer

Prednisolone for 3 days is given in treatment.

Question 4

An 8-year-old boy presents with a 6-month history of an ill-defined, hypopigmented, slightly atrophic macule on the face. What is the most likely diagnosis?

Accepted Answer

Indeterminate leprosy

Answer

Pityriasis alba

Answer

Morphoea

Answer

Calcium deficiency

Question 5

A diabetic male presents with a red, tender, and painful swelling on the right buttock with multiple discharging points. The swelling is hard and indurated, accompanied by high-grade fever and malaise. What is the most likely diagnosis?

Accepted Answer

Carbuncle

Answer

Folliculitis

Answer

Furuncle

Answer

Impetigo

Question 6

A 38-year-old male presents with swelling in the inguinal region. On examination, inguinal nodes are enlarged along with multiple discharging sinuses from the enlarged lymph nodes. What is the most probable diagnosis?

Accepted Answer

Lymphogranuloma venereum (LGV)

Answer

Chancroid

Answer

Syphilis

Answer

Granuloma inguinale

Question 7

A 22-year-old college student with a history of sexual exposure with a commercial sex worker presents with painful genital lesions and lymphadenopathy in the right inguinal region. What is the diagnosis?

Accepted Answer

Chancroid

Answer

Syphilis

Answer

Lymphogranuloma venereum (LGV)

Answer

Gonorrhea

Question 8

Pseudo Bubo is seen in which of the following conditions?

Accepted Answer

Granuloma inguinale (Donovanosis)

Answer

Chancroid

Answer

Lymphogranuloma venereum (LGV)

Answer

Syphilis

Question 9

Which of the following is NOT a primary site of acute gonococcal infection?

Accepted Answer

Ectocervix

Answer

Urethra

Answer

Bartholin's gland

Answer

Skene's gland (paraurethral glands)

Question 10

A 48-year-old male presents with a three-month history of non-itchy, generalized papulo-nodular lesions. Physical examination reveals no other abnormalities. Slit smear from a nodule is negative for acid-fast bacilli (AFB). Blood VDRL is reactive at a 1:2 dilution. What is the most likely diagnosis?

Accepted Answer

Secondary syphilis

Answer

Drug eruption

Answer

Lepromatous leprosy

Answer

Post kala azar dermal leishmaniasis

Bacterial Skin Infections — MCQs

Bacterial Skin Infections — MCQs

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