What symptom during a health assessment should lead a school nurse to investigate further for head lice (pediculosis capitis) in a school-age child?

Pruritus of the scalp is a significant symptom that should prompt further investigation for head lice (pediculosis capitis) in a school-age child. This intense itching is a common reaction to the bites of lice, which feed on the blood from the scalp. The presence of pruritus often indicates an infestation, as it results from the allergic response to the lice saliva as well as the friction caused by the lice moving on the scalp.

While other symptoms could be associated with various scalp conditions or infestations, they do not specifically point to head lice as clearly as pruritus does. A dry scalp may result from environmental factors or other dermatologic conditions but does not suggest an active lice infestation. Fever is typically indicative of systemic infection and is not a classic symptom of head lice. Hair loss can occur due to scratching and irritation but is a secondary effect rather than an initial symptom that would lead one to suspect lice.

In summary, the key indicator in this scenario is pruritus of the scalp, as it directly relates to the presence of lice and their effects on the scalp, making it a primary reason for school nurses to conduct further assessment for head lice infestations.