Which of the following conditions is typically associated with a lice infestation?

The presence of nits on the hair shaft is a hallmark sign of lice infestation. Nits are the eggs laid by lice and are typically found attached to the hair close to the scalp, often at the nape of the neck or behind the ears. They appear as small, white, or yellowish oval-shaped structures that can be mistaken for dandruff, but unlike dandruff, nits are firmly attached to the hair and cannot be easily brushed off. This characteristic is critical for diagnosing a lice infestation, as finding nits indicates that lice are present or have been present.

While other conditions, like a dry, flaky scalp, swollen lymph nodes, or a red and inflamed scalp, may be associated with various dermatological or infectious conditions, they are not specifically linked to lice. For instance, a dry scalp may indicate dermatitis or other skin conditions, swollen lymph nodes typically suggest an infection elsewhere in the body, and a red and inflamed scalp can result from irritation or allergic reactions. However, the definitive indicator for lice is the identification of nits on the hair shaft.