Which category do head lice fall under?

Head lice belong to the category of external parasites. These are organisms that live on a host and feed off of it, in this case, human blood. Head lice are specifically adapted to live in human hair and are not capable of surviving off of a host for long periods, relying on the host for sustenance. They can cause irritation and discomfort but do not transmit diseases.

Understanding external parasites is crucial for estheticians because lice can affect clients’ hair and scalp health. Recognizing the signs of an infestation and knowing the proper protocols for dealing with it is essential in a professional setting. The other categories—viruses, bacteria, and fungi—represent different types of pathogens that cause various infections or conditions but do not share the same biological characteristics as head lice. Viruses and bacteria are microorganisms that can cause diseases, while fungi include yeasts and molds, which can also lead to skin conditions. Each has different implications for treatment and care in an esthetic context.