Head lice eradication products: risk of serious burns if treated hair is exposed to open flames or other sources of ignition, eg, cigarettes

Pharmacists should tell people about the risk of fire when they discuss head lice eradication options.

Advice to pharmacists

  • some products for the eradication of head lice infestations are combustible/flammable when on the hair and can ignite and cause serious harm in the presence of an open flame or other source of ignition such as when lighting cigarettes

  • advise parents, caregivers and the person with head lice, if appropriate, that they should not smoke around treated hair and that it should be kept away from open flames or other sources of ignition, including in the morning after overnight application until hair is washed

  • always advise parents and caregivers and the person with head lice to read the instructions that come with treatments to ensure that they are used safely and correctly

  • report suspected adverse drug reactions, including burns, to the Yellow Card Scheme


A range of products including Hedrin, Full Marks, and Nyda, are used for the eradication of head lice infestations.

Pharmacists are encouraged to help the person with head lice and their parents or caregivers to consider the advantages and disadvantages of each treatment option (see NHS page on Head lice and nits and the Head lice Clinical Knowledge Summary from NICE for more information on options for eradication).

Cases of serious burns following combustion of hair

Eight cases of serious burns associated with Hedrin 4% cutaneous solution have been reported to the MHRA since the product was licensed in 2005. Following the first reported case in 2007, warnings about risk of fires were added to the pack and patient information leaflet for Hedrin 4% cutaneous solution. Four cases were associated with a cigarette lighter or lighting of a cigarette, one with a lit cigarette, one with a candle, and 2 with adjusting a gas fire.

There have been 2 further serious burns cases associated with other products. In 2006 a woman suffered serious burns when smoking during treatment. In 2017 another incident occurred when a child undergoing treatment came into contact with a naked flame, resulting in very serious burns.

Pharmacists should encourage parents, caregivers, and people with head lice to read the instructions carefully for all headlice eradication products.

Article citation: Drug Safety Update volume 11 issue 8; March 2018: 3.

Published 8 March 2018