Cutaneous Leishmaniasis — MCQs
Following are larval control measures, except:
All of the following helps in the diagnosis of leishmaniasis except:
A 42-year-old Bengali male presents with painless nodules over the face. The face is erythematous, and the surface of some of the large nodules is discolored. He gives a history of an insect bite in the past while he went to the jungle for work. What is the most likely diagnosis?
Montenegro test is used for diagnosis of:
A woman traveling from Bihar to Delhi is suspected to have Kala-azar. Suitable investigation is?
Mass Drug Administration is NOT routinely used as the primary strategy for:
Delhi boil refers to:
26-year-old man from Bihar presents with erythematous papules on the face and back of the neck, which are hypopigmented and normoaesthetic, with no nerve thickening. A history of prolonged fever in childhood is present. What is the diagnosis?
A 56 year old gardener presents with an ulcerative nodule with purulent discharge on his right index finger. He had a prick with a thorn, at the same site around a month back. Which one of the following infections is most likely?
Which of the following is NOT associated with erythema nodosum?
Cutaneous Leishmaniasis Indian Medical PG Practice Questions and MCQs
Question 1: Following are larval control measures, except:
- A. DDT (Correct Answer)
- B. Gambusia
- C. Intermittent irrigation
- D. Paris green
Explanation: ***DDT*** - **DDT (dichlorodiphenyltrichloroethane)** is primarily classified as an **adulticide** in vector control programs, used mainly for **indoor residual spraying** to kill adult mosquitoes. - While DDT can kill larvae when applied to water, it is **not typically categorized as a larval control measure** in public health practice due to environmental concerns and its primary use against adult vectors. - Its mechanism involves interfering with the **nervous system** of insects, causing paralysis and death. *Paris green* - **Paris green** is a chemical compound historically used as a **larvicide**, particularly effective against **Anopheles larvae** in stagnant water. - It works as a **stomach poison** for larvae when ingested during feeding, making it a specific larval control agent. *Gambusia* - **Gambusia**, also known as **mosquitofish**, are small fish that feed on mosquito larvae, making them a **biological control measure** for larval populations. - They are often introduced into ponds, ditches, and other water bodies to naturally reduce larval numbers. *Intermittent irrigation* - **Intermittent irrigation** is an **environmental manipulation method** that involves draining and refilling water sources at regular intervals, effectively destroying **larval breeding sites**. - This method prevents larvae from completing their development cycle by eliminating the aquatic environment they depend on.
Question 2: All of the following helps in the diagnosis of leishmaniasis except:
- A. Immobilisation test (Correct Answer)
- B. Examination of the bone marrow
- C. Blood smear
- D. Aldehyde test
Explanation: ***Immobilisation test*** - The **immobilisation test** is used to detect antibodies that inhibit the motility of organisms like *Trypanosoma cruzi* (Chagas disease), not *Leishmania*. - This test is not relevant for the diagnosis of leishmaniasis, as it targets a different parasitic mobility mechanism. *Examination of the bone marrow* - **Bone marrow aspiration** is a highly sensitive and specific method for diagnosing visceral leishmaniasis because **amastigotes** of *Leishmania* parasites are found intracellularly within macrophages in the bone marrow. - Direct visualization of the parasites in bone marrow smears confirms the diagnosis. *Blood smear* - While generally less sensitive than bone marrow aspiration, a **peripheral blood smear** can occasionally reveal **amastigotes** in circulating monocytes during the acute phase of visceral leishmaniasis. - However, its diagnostic utility is limited as the parasitic load in peripheral blood is often low. *Aldehyde test* - The **formol gel test** (also known as the **aldehyde test** or Napier's aldehyde test) is a non-specific test for **hypergammaglobulinemia**, which is a common finding in long-standing visceral leishmaniasis. - A positive result (gelation of serum after adding formaldehyde) suggests chronic infection but does not specifically confirm leishmaniasis nor differentiate it from other chronic inflammatory conditions.
Question 3: A 42-year-old Bengali male presents with painless nodules over the face. The face is erythematous, and the surface of some of the large nodules is discolored. He gives a history of an insect bite in the past while he went to the jungle for work. What is the most likely diagnosis?
- A. Chronic Fungal infections
- B. Cutaneous Leishmaniasis (Correct Answer)
- C. Cutaneous tuberculosis
- D. Leprosy
Explanation: ***Cutaneous Leishmaniasis*** - The presentation of **painless erythematous nodules** on the face, especially in a person with a history of **insect bites** and exposure to a **jungle environment** (where sandflies, vectors of Leishmania, are common), strongly suggests cutaneous leishmaniasis. - The discoloration of the surface of large nodules is also consistent with the typical appearance of **chronic cutaneous leishmaniasis lesions**. *Chronic Fungal infections* - While chronic fungal infections can cause skin nodules, they typically present with features like **scaling, itching, or satellite lesions**, which are not described here. - The specific history of **insect bites** and geographical context points away from common fungal etiologies. *Cutaneous tuberculosis* - Cutaneous tuberculosis can manifest as nodules (**lupus vulgaris** or **scrofuloderma**), but these are often associated with other signs of tuberculosis, such as **pulmonary involvement** or **lymph nodal enlargement**, and typically have a slower progression. - The history of **insect bite** is not a primary risk factor for cutaneous tuberculosis. *Leprosy* - Leprosy, particularly **lepromatous leprosy**, can cause extensive facial nodules, but these are often associated with **nerve involvement** leading to sensory loss, and the lesions tend to be diffusely infiltrative rather than discrete, discolored nodules. - The rapid onset or history of a single insect bite is less characteristic of leprosy, which has a very **long incubation period**.
Question 4: Montenegro test is used for diagnosis of:
- A. Leptospirosis
- B. Malaria
- C. Leprosy
- D. Kala azar (Correct Answer)
Explanation: ***Kala azar*** - The Montenegro test, also known as the **leishmanin skin test (LST)**, detects delayed-type hypersensitivity to **Leishmania antigens**, indicating past or present infection with *Leishmania donovani*, the causative agent of **kala azar (visceral leishmaniasis)** [1]. - A **positive reaction** (induration of 5 mm or more) signifies cell-mediated immunity against the parasite [1]. *Leptospirosis* - Diagnosed primarily through **serological tests** like the **Microscopic Agglutination Test (MAT)** or by detecting the organism through **culture** or **PCR**. - The Montenegro test is not used for the diagnosis of **leptospirosis**. *Malaria* - Diagnosed by identifying **parasites in blood smears** (thick and thin films) or by **antigen detection rapid diagnostic tests (RDTs)**. - The Montenegro test plays no role in the diagnosis of **malaria**. *Leprosy* - Diagnosed through **clinical signs and symptoms**, microscopic examination of **skin or nerve biopsies for acid-fast bacilli**, or sometimes the **lepromin skin test**. - While the lepromin test is a skin test, it targets *Mycobacterium leprae* antigens and is distinct from the Montenegro test for leishmaniasis.
Question 5: A woman traveling from Bihar to Delhi is suspected to have Kala-azar. Suitable investigation is?
- A. P24 antigen
- B. Rk-39 test (Correct Answer)
- C. Combo RDT
- D. HRP-2 antigen
Explanation: ***Rk-39 test*** - The **Rk-39 test** is a rapid diagnostic test highly sensitive and specific for detecting antibodies against the **kinesin-related protein K39** of *Leishmania donovani*, the causative agent of **Kala-azar (visceral leishmaniasis)**. - It is particularly useful in **endemic regions** like Bihar for quick and accurate diagnosis, especially in patients with suspected Kala-azar presenting with fever, splenomegaly, and pancytopenia. *P24 antigen* - **P24 antigen** testing is primarily used for the diagnosis of **HIV infection**. - It detects the **core protein p24** of the HIV virus, which is not relevant for the diagnosis of Kala-azar. *Combo RDT* - A **Combo RDT** (Rapid Diagnostic Test), without further specification, typically refers to tests for **malaria**, which detect antigens like **HRP-2** and **aldolase**. - While RDTs are used for parasitic diseases, this general term does not specifically refer to a test for **Kala-azar**. *HRP-2 antigen* - **HRP-2 (Histidine-rich protein 2) antigen** is a specific marker for **Plasmodium falciparum**, used in the diagnosis of **malaria**. - It is not associated with the diagnosis of **Kala-azar**, which is caused by *Leishmania donovani*.
Question 6: Mass Drug Administration is NOT routinely used as the primary strategy for:
- A. Vitamin A Deficiency
- B. Scabies (Correct Answer)
- C. Lymphatic Filariasis
- D. Worm infestation
Explanation: ***Scabies*** - While **mass drug administration with oral ivermectin** has shown effectiveness in specific endemic outbreak settings, MDA is generally **not the primary recommended strategy** for routine scabies control in most public health contexts. - Scabies control typically prioritizes **case finding, contact tracing, simultaneous household treatment, and environmental decontamination**—which are more complex to implement than standard MDA programs. - Unlike the other conditions listed, scabies lacks well-established **routine MDA programs** at the scale of national public health initiatives, making it the least suitable option for MDA among these choices. *Vitamin A Deficiency* - **Vitamin A supplementation** through MDA is a **highly effective and widely implemented** WHO-recommended strategy to combat Vitamin A deficiency in at-risk populations, particularly children under 5 years. - Regular mass supplementation helps prevent **xerophthalmia** and reduces morbidity and mortality from infectious diseases. - This is a cornerstone of routine public health programs globally. *Lymphatic Filariasis* - **Lymphatic filariasis** is a classic example where MDA with anti-filarial drugs like **diethylcarbamazine (DEC), albendazole,** or **ivermectin** is the cornerstone strategy for interrupting transmission. - MDA is the **primary WHO-recommended approach** to achieve elimination of lymphatic filariasis, with established national programs in endemic countries. *Worm infestation* - **Mass deworming programs** using drugs like **albendazole** or **mebendazole** represent highly effective and well-established forms of MDA for controlling **soil-transmitted helminth infections**. - These routine programs significantly reduce disease burden in school-aged children, improving nutritional status, growth, and learning outcomes.
Question 7: Delhi boil refers to:
- A. Solar Keratosis
- B. Venereal ulcer
- C. Malignant pustule
- D. L. tropica sore (Correct Answer)
Explanation: ***L. tropica sore*** - Delhi boil is a common name for cutaneous **leishmaniasis**, specifically caused by **Leishmania tropica**. - This condition presents as a **skin lesion** or sore, primarily in endemic regions like Delhi. *Solar Keratosis* - Solar keratosis is a **precancerous skin lesion** caused by long-term exposure to ultraviolet (UV) radiation from the sun. - It presents as a **rough, scaly patch** on sun-exposed areas and is not associated with parasitic infection. *Venereal ulcer* - A venereal ulcer is a **genital sore** typically caused by sexually transmitted infections (STIs) such as syphilis, herpes, or chancroid. - These ulcers are localized to the genital area and have a different etiology and clinical presentation than Delhi boil. *Malignant pustule* - A malignant pustule is a term sometimes used historically to describe **anthrax skin lesions** due to their necrotic and often black center, but more generally refers to a pustular lesion with malignant or highly aggressive characteristics. - It is not a synonym for Delhi boil, which is a parasitic infection with a distinct clinical course and etiology.
Question 8: 26-year-old man from Bihar presents with erythematous papules on the face and back of the neck, which are hypopigmented and normoaesthetic, with no nerve thickening. A history of prolonged fever in childhood is present. What is the diagnosis?
- A. Tuberculoid leprosy
- B. Lepromatous leprosy
- C. Lupus vulgaris
- D. Dermal leishmaniasis (PKDL) (Correct Answer)
Explanation: ***Dermal leishmaniasis (PKDL)*** - PKDL presents with **erythematous papules** on the face and neck, which are **hypopigmented and normoaesthetic** (intact sensation), fitting the patient's description perfectly. - A history of **prolonged fever in childhood** in Bihar is highly suggestive of prior **visceral leishmaniasis (kala-azar)**, after which PKDL typically develops (months to years post-treatment). - The **absence of nerve thickening** and **normal sensation** are key features distinguishing PKDL from leprosy. - Bihar is an **endemic area** for visceral leishmaniasis in India. *Tuberculoid leprosy* - Characterized by **hypopigmented, anaesthetic patches** with **thickened nerves** - both features are absent in this case. - The **normoaesthetic** nature of lesions here rules out tuberculoid leprosy. - Lesions are typically **well-demarcated** and few in number. *Lepromatous leprosy* - Involves widespread, symmetrical lesions that are often **erythematous nodules** or **diffuse infiltrations**, with multiple nerve involvements. - Would show **nerve thickening** and eventual sensory loss, which are not present here. - The clinical picture does not match lepromatous leprosy. *Lupus vulgaris* - A form of **cutaneous tuberculosis** presenting as red-brown plaques with an **"apple-jelly" appearance** on diascopy. - While it can occur on the face, there is no history of fever or connection to visceral leishmaniasis. - The morphology (papules vs plaques) and epidemiological context favor PKDL.
Question 9: A 56 year old gardener presents with an ulcerative nodule with purulent discharge on his right index finger. He had a prick with a thorn, at the same site around a month back. Which one of the following infections is most likely?
- A. Chromoblastomycosis
- B. Phaeohyphomycosis
- C. Mycetoma
- D. Sporotrichosis (Correct Answer)
Explanation: ***Sporotrichosis*** - This presentation, an **ulcerative nodule with purulent discharge** on a finger after a **thorn prick** in a gardener, is classic for **sporotrichosis** (rose gardener's disease). - The organism, *Sporothrix schenckii*, is found in soil, plants, and decaying vegetation and typically enters through **skin trauma**. *Chromoblastomycosis* - Characteristically presents with **verrucous (warty) plaques or nodules** that slowly enlarge; it does not typically show the ulcerative nodule with purulent discharge found here. - While it can be acquired through trauma, the **morphology of the lesions** differs from the described case. *Phaeohyphomycosis* - This is a broad term for infections caused by dematiaceous (pigmented) fungi that typically present as **subcutaneous cysts, abscesses, or nodules**, but the specific clinical picture of **lymphocutaneous spread** following trauma is less characteristic than sporotrichosis. - The lesions tend to be more **encapsulated or abscess-like** rather than the ulcerative, purulent nodule described. *Mycetoma* - Mycetoma presents as a **chronic, localized, progressively destructive infection** of the skin, subcutaneous tissue, fascia, and bone, often characterized by **swelling, draining sinuses, and grains** (microcolonies of the causative organism). - While it can be acquired via trauma, the typical presentation is much more **extensive and chronic** than the initial ulcerative nodule described.
Question 10: Which of the following is NOT associated with erythema nodosum?
- A. Pemphigus vulgaris (Correct Answer)
- B. Tuberculosis
- C. Sarcoidosis
- D. Leprosy
Explanation: ***Pemphigus vulgaris*** - **Pemphigus vulgaris** is an **autoimmune blistering disease** that affects the skin and mucous membranes, characterized by flaccid bullae, not subcutaneous nodules. - Its pathophysiology involves **autoantibodies** against **desmoglein 1 and 3**, leading to **acantholysis**, which is distinct from the inflammatory changes seen in erythema nodosum. *Tuberculosis* - **Tuberculosis (TB)** is a common infectious cause of **erythema nodosum**, especially in regions with high TB prevalence. - The development of erythema nodosum in TB is often considered a **hypersensitivity reaction** to mycobacterial antigens. *Sarcoidosis* - **Sarcoidosis** is a systemic granulomatous disease, and **erythema nodosum** can be a prominent cutaneous manifestation, particularly in **Löfgren's syndrome**. - Its presence with **bilateral hilar lymphadenopathy** and **arthralgia** is highly suggestive of acute sarcoidosis. *Leprosy* - **Leprosy**, caused by *Mycobacterium leprae*, can be associated with **erythema nodosum leprosum (ENL)**, which is a type 2 lepra reaction. - **ENL** involves the formation of painful, tender, inflamed nodules that resemble erythema nodosum and is linked to elevated immune complex deposition.
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