Final answer:
Perianal skin tags or fissures would be highly suspicious findings for Crohn's disease during a physical examination, as they are specific signs of this inflammatory bowel disease.
Step-by-step explanation:
The nurse conducting a physical examination of a child with suspected Crohn's disease would interpret perianal skin tags or fissures as highly suspicious of this disorder. While some of the other options like abdominal tenderness may be associated with Crohn's disease, perianal abnormalities are more specific and thus more suspicious for this condition compared to normal growth patterns or precocious puberty. Crohn's disease is a type of inflammatory bowel disease that can cause various symptoms, including abdominal pain, persistent diarrhea, fever, weight loss, and could also lead to complications like bowel obstructions, abscesses, and an increased risk for bowel cancer.