What disease is lice? - briefly
Lice are external parasites that infest hair and skin, causing the condition known as pediculosis. The infestation may produce itching and secondary bacterial infection but is not classified as a disease itself.
What disease is lice? - in detail
Lice are obligate ectoparasites that feed on human blood. Three species commonly affect people: Pediculus humanus capitis (head lice), Pediculus humanus corporis (body lice), and Pthirus pubis (pubic lice). Each species has a specific habitat on the host and a distinct pattern of transmission.
Head lice spread primarily through direct head-to-head contact, occasionally via personal items such as combs, hats, or pillows. Infestation manifests as itching caused by allergic reactions to saliva, visible nits attached to hair shafts, and occasional red papules on the scalp. Diagnosis relies on visual inspection for live insects and their eggs; magnification may improve detection.
Body lice reside in clothing seams and move to the skin to feed. They transmit bacterial pathogens, including Rickettsia prowazekii, Bartonella quintana, and Borrelia recurrentis. Symptoms include intense itching, a maculopapular rash, and secondary skin infections. Identification involves finding live lice or nits on garments and observing excoriations on the body.
Pubic lice infest the coarse hair of the genital region, perianal area, or chest. Transmission occurs through sexual contact or sharing of contaminated clothing and bedding. Presentation includes pruritus, blue-gray macules at bite sites, and visible lice or eggs on hair shafts.
Treatment options differ by species but share common principles:
- Topical pediculicides: permethrin 1% lotion, pyrethrin‑based shampoos, or ivermectin cream applied according to manufacturer instructions.
- Oral agents: ivermectin tablets for resistant cases, or azithromycin for secondary bacterial infection.
- Mechanical removal: fine-toothed combs used on wet hair to extract nits; repeated combing over 7–10 days reduces re‑infestation.
- Environmental control: washing bedding, clothing, and towels at ≥60 °C, sealing non‑washable items in sealed bags for two weeks, vacuuming upholstered furniture.
Prevention focuses on minimizing head-to-head contact in schools, avoiding sharing personal items, and maintaining clean clothing and bedding. For body lice, regular laundering of clothing and prompt treatment of overcrowded living conditions are essential. Pubic lice prevention aligns with safe sexual practices and personal hygiene.
Complications may include secondary bacterial skin infections, anemia in severe infestations, and, in the case of body lice, systemic disease from vector‑borne pathogens. Resistance to common pediculicides has been documented, prompting the need for alternative agents and integrated management strategies.