Final answer:
Cutaneous larva migrans (CLM) is caused by the larvae of hookworms, specifically option 2, which penetrate human skin and create pruritic tracks. It is not related to scabies, lice, or ticks.
Step-by-step explanation:
Cutaneous larva migrans (CLM) is a zoonotic skin disease caused by the larvae of certain hookworm species such as Ancylostoma braziliense, commonly found in animals like cats and dogs. When these hookworm larvae penetrate human skin, they migrate within the subcutaneous tissue, leading to the appearance of pruritic, serpiginous tracks on the skin. CLM is not associated with scabies, lice, or ticks, making option 2, hookworm, the correct answer to the student's question.
These hookworm larvae, once in contact with human skin, often at the feet, create these tracks as they travel beneath the surface. The condition can be uncomfortable due to the itching it causes, but it does not develop into a full systemic infection as the larvae cannot mature in humans. Figures and descriptions such as those in Figure 24.33 are used to illustrate the hookworm attachment to the intestinal wall, the visible tracks on the skin in someone with CLM, and the microscopic egg of a hookworm.