Dimeticone 4% lotion
Dose:  Head lice, rub into dry hair and scalp, allow to dry naturally, shampoo after a minimum of 8 hours (or overnight); repeat application after 7 days.

Malathion 0.5% in aqueous basis
Dose:  Head lice, rub into dry hair and scalp, allow to dry naturally, remove by washing after 12 hours and repeat treatment after 7 days. Crab/pubic lice, apply aqueous preparation to all parts of the body (not merely the groin and axillae) for 12 hours, or overnight; a second treatment needed after 7 days to kill lice emerging from surviving eggs.

Several products are available which require the use of a fine tooth plastic detection comb and hair conditioner; a head lice device (Bug Buster^® Kit) is prescribable on the NHS.  The methods typically involve meticulous combing with the detection comb over the whole scalp at 4 day intervals for at least 2 weeks.

Permethrin cream 5%
Dose:  Scabies: apply over whole body including face, neck and ears and wash off after 8 to 12 hours. Those with sparse hair should also apply the cream to their scalp.  If hands are washed with soap and water within 8 hours of application, cream should be re-applied.  Repeat treatment after 7 days.  All members of household/close contacts should be treated once only. 

Refer to notes on “treatment of scabies” click here