🧴 Head Lice: A Complete Guide for PLAB 2 Candidates
- examiner mla
- 5 days ago
- 4 min read
Updated: 3 days ago
Head lice (Pediculus humanus capitis) are a common cause of scalp itching in children, especially those of school age. They are not a sign of poor hygiene and do not spread disease, but they cause discomfort, distress, and social stigma.
In PLAB 2, head lice often come up in telephone consultations or parental concern stations, where the focus is on giving safe, structured advice according to NHS guidance.
History & Data Gathering
In PLAB 2, you should ask:
Duration and severity (itching, scratching, sleep disturbance).
Treatment tried (shampoo, combing, repeat applications?).
Other household members affected?
Evidence of live lice (parent seen moving lice/nits).
Signs of secondary infection (redness, pus, crusting).
Social impact (school, embarrassment, stigma).
🔍 Diagnosis
Made clinically: live lice seen (moving insects).
Nits (eggs) alone are not enough to diagnose.
Confirm with a detection comb (fine-toothed comb, teeth 0.2–0.3 mm apart).
No lab tests required.
🧾 Management Plan
1. Education & Reassurance
Head lice are common; not linked to poor hygiene.
Olivia (or any child) can continue going to school. Exclusion is unnecessary.
2. Check Household & Contacts
Examine all household members using a detection comb.
Treat only those with live lice, but treat them at the same time to prevent re-infestation (“ping-pong effect”).
Asymptomatic adults can carry lice → checking is vital.
🧾 Treatment Options and Their Rationale
1. Detection & Confirmation
Always confirm live lice are present before treating.
Use a fine-toothed detection comb (0.2–0.3 mm spacing).
Avoid “treating just in case” — unnecessary use contributes to treatment failure and resistance.
2. Lotion or Spray (Preferred by NHS)
Dimeticone 4% lotion or spray
Works by coating and suffocating lice (physical action, not chemical).
Effective even where chemical resistance exists.
Safe for children aged 6 months and over.
Must be applied to dry hair, left on for 8 hours/overnight, and repeated after 7 days.
Reasoning:
Unlike insecticidal shampoos, lotions/sprays stay on the scalp longer, ensuring full coverage.
Physical mode of action means resistance is unlikely.
Advice on Application of Head Lice Lotion (e.g. Dimeticone 4%)
Preparation
Start with dry hair.
Make sure there is enough lotion — the whole scalp and hair must be saturated. (One bottle may not be enough for long or thick hair).
Protect clothes with a towel.
Application
Apply the lotion directly onto the scalp and hair roots first, then work through to the ends.
Massage it in thoroughly, section by section, until all hair is covered and visibly wet with the product.
Pay special attention to the nape of the neck and behind the ears (lice hotspots).
Leaving Time
Leave the lotion/spray on for the time stated in the instructions (usually 8 hours / overnight for dimeticone 4%).
Do not use a hairdryer while the lotion is on (flammability risk with some products).
Washing Out
After the required time, wash out with normal shampoo.
Conditioner may be used to help remove product residue.
Use a fine-toothed comb to check for lice after washing.
Repeat Application
Repeat the entire process after 7 days.
This second treatment kills any lice that have hatched since the first dose.
Practical Tips
Make sure all affected household members are treated on the same day.
Do not mix different products at the same time.
Avoid head lice “shampoos” — they rinse off too quickly to be effective.
Wash or soak combs/brushes in hot water after use.
3. Bug Buster Wet Combing Kit
Method: Conditioner + fine-toothed combing.
Done on days 1, 5, 9, 13 to remove lice as they hatch.
Continue until no lice are found on 3 consecutive sessions.
Reasoning:
Non-chemical, safe for all ages.
Effective if done thoroughly, but time-consuming and requires parental commitment.
Step 1 – Preparation
Wash the child’s hair with ordinary shampoo.
Apply plenty of conditioner to wet hair (makes combing easier and stuns lice).
Detangle with a wide-toothed comb first.
Step 2 – Sectioning
Divide the hair into small sections.
Use hair clips if needed to keep sections apart.
Step 3 – Fine Combing
Place the fine-toothed detection comb at the roots, touching the scalp.
Pull comb slowly and firmly all the way to the hair tips.
After each stroke, wipe the comb on white tissue/paper to check for lice.
Step 4 – Systematic Approach
Comb the entire head, section by section.
Pay special attention behind the ears and at the nape of the neck (lice hotspots).
Step 5 – Repetition
Repeat every 3–4 days for at least 2 weeks.
The Bug Buster programme recommends sessions on days 1, 5, 9, and 13 (this covers the hatching cycle).
Continue until no lice are found on 3 consecutive sessions.
4. Other Physical Products
Isopropyl myristate/cyclomethicone (Hedrin Once) — dissolves the protective coating of lice, killing them.
Usually applied once, but may need repeating if reinfestation occurs.
Reasoning:
Provides an alternative when dimeticone has failed or parents prefer a shorter course.
5. What NOT to Do
Do not use insecticidal shampoos (permethrin, malathion) → widespread resistance, rinse off too quickly.
Do not treat prophylactically → only treat those with live lice.
Do not deep-clean the house → lice cannot survive more than 1–2 days off the scalp.
🏠 Household and School Advice
Check all household members with a detection comb.
Treat only those with live lice, but treat them simultaneously.
Wash or soak combs/brushes in hot water (≥60°C).
Avoid sharing hats, towels, or hair accessories.
Children can continue school — exclusion is unnecessary.
🛟 What to Do in Case of Treatment Failure
Check technique first
Was enough product used?
Was hair fully saturated?
Was the second application done after 7 days?
Switch to a different method
If lotion/spray failed → try Bug Buster wet combing or Hedrin Once.
If combing failed → try dimeticone lotion.
Review close contacts
Make sure all affected family members were treated together.
Seek GP review if:
Lice persist after two different, correctly used treatments.
Signs of secondary bacterial infection (redness, pus, swelling, fever).
✅ Key Takeaways
First-line: Dimeticone 4% lotion/spray (repeat in 7 days).
Alternative: Bug Buster combing or Hedrin Once.
Household: Check all, treat only those with live lice.
Failure: Check technique → switch treatment → GP review if persistent.
Reassure: Not a hygiene issue; child can attend school.
📚 References
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