🏥 Stations

🧠 Qbank

📖 Book

😃 More

💳 Pricing

🔒 Dashboard

📖 OSCE Learning

🔒 OSCE Stations

🔒 Qbank

🔐 Membership
Share your insights

Help us by sharing what content you've recieved in your exams


Head lice

Medicine > Infection

Background knowledge 🧠

Definition

  • Head lice (Pediculus humanus capitis) are parasitic insects that infest the human scalp and hair.
  • They feed on blood from the scalp.
  • Infestations are common in children and can spread through close contact.
  • Not a health hazard, but can cause itching and discomfort.

Epidemiology

  • Common in school-aged children.
  • Outbreaks often occur in school and childcare settings.
  • Higher prevalence in girls due to longer hair.
  • Not related to personal hygiene or socioeconomic status.
  • Seasonal peaks in autumn and early winter.

Aetiology and pathophysiology

  • Caused by infestation with Pediculus humanus capitis.
  • Lice lay eggs (nits) on hair shafts close to the scalp.
  • Nits hatch into nymphs, which mature into adult lice.
  • Lice feed on blood from the scalp multiple times a day.
  • Transmission through direct head-to-head contact or sharing personal items.
  • Intense itching caused by allergic reaction to lice saliva.

Clinical Features 🌡️

Symptoms

  • Intense itching of the scalp, particularly behind the ears and at the nape of the neck.
  • Sensation of something moving in the hair.
  • Difficulty sleeping due to scalp itching.
  • Sores on the scalp caused by scratching.
  • Secondary bacterial infection from scratching.

Signs

  • Visible lice on the scalp and hair.
  • Nits (lice eggs) attached to hair shafts close to the scalp.
  • Red bumps or sores on the scalp, neck, and shoulders.
  • Lymphadenopathy in severe cases due to secondary infection.
  • Signs of excoriation from persistent scratching.
  • Secondary impetigo if bacterial infection present.

Investigations 🧪

Tests

  • Diagnosis primarily clinical based on visual inspection.
  • Use of a fine-toothed comb to detect live lice and nits.
  • No laboratory tests typically required.
  • Examination of family members and close contacts recommended.
  • Consider secondary bacterial infection if sores or lymphadenopathy present.
  • Dermatologist consultation if diagnosis uncertain or treatment-resistant cases.

Management 🥼

Management

  • Topical pediculicides: permethrin 1% lotion or malathion 0.5% lotion.
  • Mechanical removal with fine-toothed lice comb every 3-4 days for 2 weeks.
  • Treat all household members and close contacts simultaneously.
  • Wash bedding, clothing, and hats in hot water (60°C) and dry on high heat.
  • Avoid sharing personal items such as combs, hats, and headphones.
  • Educate patients and parents on proper application of treatments and prevention strategies.
  • Consider retreatment in 7-10 days if live lice persist.
  • Oral ivermectin in cases of treatment failure or resistance.

Complications

  • Secondary bacterial infection from scratching.
  • Impetigo: a bacterial skin infection.
  • Lymphadenopathy due to secondary infection.
  • Significant itching and discomfort affecting sleep and concentration.
  • Psychological distress and social stigma.
  • Allergic reactions to lice bites or treatments.
  • Potential resistance to standard treatments requiring alternative approaches.

Prognosis

  • Excellent with appropriate treatment and adherence to management strategies.
  • Recurrence common if all household members and contacts are not treated simultaneously.
  • Good personal hygiene practices and regular checking reduce risk of reinfestation.
  • Prompt treatment of secondary infections ensures no lasting complications.
  • Awareness and education critical for effective control and prevention.

Key points

  • Head lice infestations are common and not indicative of poor hygiene.
  • Effective treatment includes both chemical and mechanical removal methods.
  • Education on prevention and treatment is essential to reduce spread and recurrence.
  • Treat all close contacts simultaneously to prevent reinfestation.
  • Regular checking of hair can help detect lice early and prevent large outbreaks.
  • Secondary infections from scratching require prompt treatment.
  • Social stigma and psychological distress associated with infestations should be addressed.

No comments yet 😉

Leave a Reply

Infection