**Core Concept:** The adhesive tape test is a non-invasive method used to detect the presence of eggs of certain parasitic worms on the skin surface, which may indicate a parasitic infection. The test involves applying adhesive tape to the skin lesions, fixing it, and then staining the tape to visualize the eggs. This test is particularly useful for detecting soil-transmitted helminths like hookworms and roundworms.

**Why the Correct Answer is Right:** In this case, the patient presents with intense perianal itching and perianal excoriation, indicating a possible infection. An adhesive tape test is performed, which is positive for worm eggs. The most common soil-transmitted helminths causing perianal itching and excoriation include roundworms (Ascaris lumbricoides) and hookworms (Necator americanus and Ancylostoma duodenale). These worms are commonly found in the tropics and subtropics and are transmitted through contaminated soil.

**Why Each Wrong Option is Incorrect:**

A. Trichuris trichiura (whipworm): Trichuriasis usually presents with abdominal pain and diarrhoea, not perianal symptoms.
B. Schistosomiasis (bilharziasis): The worms cause bladder and urethral involvement, not perianal symptoms.
C. Strongyloides stercoralis: Strongyloidiasis presents with systemic symptoms (fever, malaise) and eosinophilia, not perianal symptoms.
D. Enterobius vermicularis (pinworm): Pinworm infection is usually seen in young children, but the symptoms are typically non-specific, causing irritability and frequent awakening at night.

**Clinical Pearl:** The most common cause of perianal itching and excoriation in a child from a tropical or subtropical region is typically A. hookworm infection. The worm eggs are present in the tape test, and the patient's age, geography, and clinical presentation align with the diagnosis of hookworm infection.