Head Lice, Pubic Lice & Body Lice

Head lice

Most infestations are asymptomatic; may cause scalp/nape-of-neck itching, which can take 2–6 weeks to develop after the initial infestation. Confirmed by observing a moving louse or a viable egg — nits (empty egg casings) alone do not confirm active infestation, since they can remain glued to the hair for months after successful treatment; dandruff, hairspray residue and hair casts mimic nits but brush off easily, unlike a true nit’s glue-like attachment to the hair shaft.

Wet combing

Wet hair with copious conditioner (stuns lice, stops crawling for ~20 min); divide into 3–4 cm sections; comb with a fine-tooth comb, wiping onto paper towel to check for lice/eggs. Effective around 40% of the time on its own if repeated daily until no lice are found — cure rates with combing alone vary widely between studies.

Insecticide treatment

Product	Application
Permethrin 1%	10 min, then wash out; repeat in 7 days
Maldison (malathion) 1%	Wash out after 12 hours (overnight); repeat in 7 days
Pyrethrins 0.165% + piperonyl butoxide 1.65%	10 min
Dimeticone 4% (a physical suffocant, not an insecticide)	2 applications 1 week apart; ~69–92% cure rate

Permethrin resistance is widespread in Australia and it has largely been discontinued as first-line treatment; maldison and pyrethrin-based products are current alternatives, although malathion resistance is also increasingly reported, with cure rates as low as 33% in some series. Dimeticone works by physically coating and suffocating lice rather than by a chemical/neurotoxic mechanism, so resistance to it is not expected — it is a reasonable alternative where insecticide resistance is suspected or repeated insecticide courses have failed.

If treatment fails

Most “treatment failure” is due to non-adherence (missing the second application 7–10 days later), inadequate application (wrong amount or duration) or failure to physically remove nits — true insecticide resistance is a less common cause than these. Re-examine for a live louse before assuming failure; nits alone do not mean the treatment hasn’t worked. Oral ivermectin (single dose, sometimes repeated at 10 days) has been used for refractory/resistant infestations in specialist practice; its dose is not established here as a routine primary-care option and should be checked against eTG/AMH before prescribing.

Wet combing schedule around treatment

1. Day after treatment — check for live lice; if found, switch products (resistance).
2. Between treatments (×2) — remove eggs.
3. Weekly for several weeks — detect recurrence.

Household eradication

Wash brushes/combs in water ≥60°C; wash pillowcases/sheets/hats on a hot cycle; examine and treat other family members if lice found; notify the school. The child can return to school once treatment has started — routine “no-nit” exclusion policies are not evidence-based, since nits alone can persist long after successful treatment.

Differential diagnosis

Dandruff, seborrhoeic dermatitis, superficial fungal scalp infection, eczema and folliculitis can all be mistaken for pediculosis; a moving louse or viable egg on close examination (magnifying lens, bright light or a fine-tooth comb) is what actually confirms the diagnosis.

Pubic lice

May involve pubic, head, axillary or body hair, and eyebrows/eyelashes. Usually an STI in adults — infestation in a child should prompt investigation for sexual abuse. Treatment as for head lice, but examine the entire body surface; shaving pubic hair aids treatment. Examine and treat sexual partners; detection in an adult should prompt screening for other sexually transmitted infections.

Body lice

Unlike head and pubic lice, body lice live and lay eggs in the seams of clothing and bedding, moving onto the skin only to feed — infestation is therefore closely tied to infrequent clothing changes, and is more common among people who are homeless or displaced, and in colder months. Treat the whole body surface with insecticide as for head lice above (e.g. maldison 1%, washed off after 12 hours, repeated in 7 days), and wash all clothing/bedding on a hot cycle, or seal in plastic for 30 days. Untreated body lice infestation can (rarely, in Australia) transmit louse-borne diseases such as epidemic typhus, trench fever and relapsing fever, which is why persistent infestation in an at-risk population warrants closer follow-up.