Question

Cutaneous larva migrans is caused by the larvae of:
A. Ancylostoma braziliense
B. Bunostomum phlebotomum
C. Capillaria hepatica
D. Gnathostoma spp.
Choose the correct answer from the options given below:

• A. A, B and C only
• B. A, B and D only
• C. C and D only
• D. A, C and D only

Hint:

Remember that hookworms (Ancylostoma, Bunostomum) are the premier causes of superficial CLM due to direct percutaneous L3 invasion, while Gnathostoma causes a deeper subcutaneous form. Capillaria hepatica is strictly a hepatic tissue parasite acquired by egg ingestion.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Cutaneous Larva Migrans (CLM), also known as creeping eruption, is a zoonotic skin disease.
It occurs when infective third-stage nematode larvae from non-human hosts penetrate and migrate through the epidermis of abnormal hosts (such as humans).
Because these larvae cannot complete their natural life cycle in the abnormal host, they remain confined to the skin layers.
This results in erythematous, pruritic, linear, or serpiginous tracts.

Step 2: Detailed Explanation:
Let us evaluate each of the listed parasites for their ability to cause CLM:
1. Ancylostoma braziliense (A):
This hookworm of cats and dogs is the most common and classic cause of cutaneous larva migrans in humans.
The filariform larvae (L3) present in soil contaminated with pet feces readily penetrate human skin, causing highly pruritic serpiginous lesions.
Therefore, A is correct.
2. Bunostomum phlebotomum (B):
This is the cattle hookworm.
Its infective larvae can penetrate the skin of cattle (causing "dew-itch") and can also penetrate human skin, leading to cutaneous lesions typical of CLM.
Therefore, B is correct.
3. Capillaria hepatica (C):
This is a zoonotic hepatic nematode that primarily infects rodents.
Infection is acquired solely by ingestion of embryonated eggs from the environment, which hatch in the cecum, migrate via the portal vein to the liver, and mature there.
It does not involve skin penetration or cutaneous larval migration.
Therefore, C is incorrect.
4. Gnathostoma spp. (D):
These nematodes cause gnathostomiasis.
Human infection is acquired by ingesting undercooked fish containing third-stage larvae.
These larvae migrate through internal tissues and frequently enter the subcutaneous tissues, producing a form of migratory subcutaneous swelling known as cutaneous gnathostomiasis or larva migrans profundus.
Therefore, D is correct.
Thus, the causative agents of cutaneous larva migrans are A, B, and D.

Step 3: Final Answer:
The organisms capable of causing cutaneous larva migrans are Ancylostoma braziliense (A), Bunostomum phlebotomum (B), and Gnathostoma spp. (D).
Therefore, the correct answer is option (B).