Are lice dangerous? - briefly
Head lice do not transmit diseases, but their bites cause itching and can lead to skin irritation or secondary bacterial infection if scratched. Their presence is a nuisance rather than a serious health hazard.
Are lice dangerous? - in detail
Lice infestations affect the scalp, body, or genital area and can cause health problems beyond simple discomfort.
Head lice (Pediculus humanus capitis) feed on blood, leading to itching that may provoke scratching. Repeated scratching can break the skin, creating entry points for bacterial infections such as Staphylococcus aureus or Streptococcus pyogenes. These secondary infections may result in cellulitis or impetigo, conditions that sometimes require antibiotic therapy.
Body lice (Pediculus humanus humanus) differ because they live in clothing and move to the skin to feed. They are vectors for serious diseases: epidemic typhus (Rickettsia prowazekii), trench fever (Bartonella quintana), and relapsing fever (Borrelia recurrentis). Outbreaks historically occurred in crowded, unhygienic settings such as refugee camps, prisons, and wartime trenches. Modern cases are rare but persist where sanitation is inadequate.
Pubic lice (Pthirus pubis) infest the coarse hair of the genital region. Their bites produce intense itching and inflammation, which can lead to secondary bacterial infection. Although they do not transmit systemic pathogens, they are markers of close sexual contact and may indicate exposure to other sexually transmitted infections.
Risk factors for infestation include close personal contact, shared bedding or clothing, and poor hygiene. Children in schools or daycare centers experience the highest prevalence of head lice, while body lice are associated with homelessness or institutional living conditions.
Control measures focus on three steps:
- Eradication: Use approved topical insecticides (e.g., permethrin 1 % or dimethicone) applied according to product instructions; repeat treatment after 7–10 days to kill newly hatched nymphs.
- Environmental decontamination: Wash clothing, bedding, and towels in hot water (≥ 60 °C) or seal items in a plastic bag for two weeks to eliminate surviving lice and eggs.
- Prevention: Conduct regular visual inspections, avoid sharing personal items, and maintain clean living conditions to reduce the likelihood of re‑infestation.
In summary, lice can pose direct health threats through skin irritation, secondary bacterial infection, and, in the case of body lice, transmission of life‑threatening diseases. Prompt identification and comprehensive treatment are essential to prevent complications.