How do lice harm? - briefly
Lice bite the scalp, extracting blood and triggering itching, inflammation, and possible secondary bacterial infection; severe infestations may cause anemia, particularly in children.
How do lice harm? - in detail
Lice infestations cause direct physiological damage to the host. Feeding activity involves piercing the skin and extracting blood, which leads to localized inflammation, itching, and micro‑abrasions. Repeated bites create red papules that may coalesce into larger lesions.
- Bacterial invasion through broken skin permits secondary infections such as impetigo or cellulitis; pathogens gain entry at bite sites.
- Allergic sensitization can develop, producing chronic urticaria or hypersensitivity reactions that persist after the parasites are eliminated.
- Hemorrhagic loss, though minimal per individual insect, may become significant in severe infestations, especially in children or individuals with compromised nutrition.
- Disruption of the scalp’s microbiome occurs as lice alter bacterial populations, potentially fostering overgrowth of opportunistic organisms.
Psychological consequences arise from visible infestation and persistent discomfort. Social stigma and embarrassment may result in reduced self‑esteem, avoidance of group activities, and impaired academic or occupational performance. In extreme cases, chronic stress contributes to sleep deprivation, which further weakens immune defenses.
Overall, lice impose a multifaceted burden: tissue damage, infection risk, allergic responses, nutritional impact, microbiome disturbance, and mental health effects. Effective control measures must address both the parasites and the secondary complications they provoke.