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Patient Case: Pediculosis (Lice Infestation)

Patient Case: Pediculosis (Lice Infestation)

Discussion

Chief Complaint: “My scalp has been itching non-stop for the past two weeks.”

History of Present Illness:
A 10-year-old girl living in a suburban area is brought to the clinic by her mother due to persistent scalp itching. The itching started two weeks ago and has progressively worsened, especially at night. Her mother noticed that she frequently scratches her head and recently found small white particles attached to her hair shafts. Some of her classmates at school have also complained of similar symptoms.

The mother tried washing her daughter’s hair frequently and using a regular shampoo, but the itching persisted. There are no other systemic symptoms such as fever or swollen lymph nodes.

Physical Examination:

  • Excoriations and redness on the scalp, particularly behind the ears and at the nape of the neck
  • Small, white oval nits (eggs) attached firmly to the hair shafts
  • A few adult lice visible crawling on the scalp
  • No signs of secondary bacterial infection

Diagnosis:
The presence of nits and adult lice confirms a diagnosis of pediculosis capitis (head lice infestation), caused by Pediculus humanus capitis.

Management Plan:

  • Topical treatment: Permethrin 1% lotion applied to the scalp and repeated in 7–10 days
  • Mechanical removal: Fine-toothed lice comb to remove nits and lice
  • Household and school precautions:
    • Check and treat close contacts if necessary
    • Wash bed linens, hats, and hair accessories in hot water
    • Educate about avoiding head-to-head contact and sharing personal items

The patient’s mother is reassured that head lice are not a sign of poor hygiene and that proper treatment will effectively eliminate the infestation. A follow-up visit is scheduled to ensure successful treatment

Questions
1. What is the most likely causative organism of this patient’s condition?

a) Sarcoptes scabiei
b) Pediculus humanus capitis
c) Tinea capitis
d) Demodex folliculorum

2. What is the most characteristic finding in pediculosis capitis?

a) Fluid-filled blisters on the scalp
b) White nits firmly attached to hair shafts
c) Painful open sores with pus
d) Thick, yellow crusting on the scalp

3. What is the first-line treatment for this condition?

a) Permethrin 1% lotion
b) Oral antibiotics
c) Antifungal shampoo
d) Corticosteroid cream

4. Why is it necessary to check and possibly treat close contacts?

a) Head lice are highly contagious and spread through direct head-to-head contact
b) Lice infestations can spread through the bloodstream
c) Head lice can cause severe systemic infections
d) All household members will always show symptoms immediately

Reveal answers

Answers

  1. (b) Pediculus humanus capitis – This parasite is responsible for head lice infestations, commonly affecting children and spreading through direct contact.
  2. (b) White nits firmly attached to hair shafts – Nits (lice eggs) are a key diagnostic feature of head lice and are often found near the scalp, especially behind the ears and at the nape of the neck.
  3. (a) Permethrin 1% lotion – This is the first-line treatment for head lice. It should be applied to the scalp and repeated in 7–10 days to kill newly hatched lice.
  4. (a) Head lice are highly contagious and spread through direct head-to-head contact – Close contacts should be checked and treated if necessary because lice spread easily, especially among school-aged children.

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