Which highly contagious infection causes inflammation primarily associated with the pilosebaceous duct?

The correct answer is linked to folliculitis, which is an infection that specifically affects the hair follicles. The term "pilosebaceous duct" refers to the structure that comprises the hair follicle and its associated sebaceous gland. This area can become inflamed due to various infectious agents or irritants, which is the hallmark of folliculitis.

In folliculitis, bacteria, commonly Staphylococcus aureus, invade the hair follicles, causing redness, swelling, and pus-filled bumps. This condition is indeed classified as contagious, particularly if the infected area is scratched or otherwise comes into contact with another person's skin. The inflammation is primarily localized around the pilosebaceous ducts, making this choice accurate for the question.

In comparison, other conditions listed, such as impetigo, which tends to occur on exposed areas and can affect any skin surface, is not exclusively linked to the pilosebaceous duct. Tinea pedis is a fungal infection of the feet, and pediculosis refers to lice infestations, neither of which specifically involve hair follicles in their pathogenetic processes. Therefore, the association of inflammation with the pilosebaceous duct singularly identifies folliculitis as the most appropriate answer.