HEAD LICE

by Dorset Health Authority

Are head lice a health hazard?

A key thing to be aware of is that head lice rarely, if ever, cause physical health problems in this country other than itching of the scalp. The colonisation of human heads by lice is a social nuisance but is neither an infectious disease nor a threat to health. Over-reaction to the presence of head lice by both the public and professionals leads to a general perception that the numbers of affected individuals are greater than they actually are. This belief can lead to unnecessary or inappropriate action and to a great deal of unwarranted anxiety and distress.

How do headlice pass from person to person?

Anybody can get head lice. Head lice cannot swim, fly, hop or jump. They require an affected head to be pressed firmly against someone else's for at least one minute in order for them to pass from one person to another. If one or two lice are passed on they may breed and slowly increase in number. At this stage most people don't have any symptoms and won't know they have head lice unless they look very carefully for them. After two or three months the scalp may start to itch badly and this may be the first time the person realises that they have got head lice. Some people, especially adults, never get the itch and may have a few lice on their heads for years without knowing it, which they can pass on to other people. So it is easy to see how lice can be passed round and round within a group of people who have close physical contact.

Are schools the source of the head lice problem?

The tendency in our present society to find a 'scapegoat' leads to schools being held responsible. Head lice are a problem of the whole community not just schools. In fact, they are mostly caught from close family and friends in the home and community not from the school. This is why careful examination of all possible head to head contacts of an affected person is so important.

Why not have a 'nit nurse'?

Before the effective control of head lice became possible with insecticidal lotions, mass head inspections within schools were a means of detecting the worst and most severe cases. Nowadays, most people affected have only a few lice and are unlikely to be identified by such a method of screening. The primary responsibilty for identification and treatment of head lice within a family lies with the parents. However, parents require adequate information and support by professionals if the identification, treatment and prevention of head lice is to be successful.

What are the responsibilities of professionals?

The Communicable Disease Control Team is responsible for advising other professionals on the control of head lice within the population as a whole. The School Health Services and Head Teachers have responsibility for giving professional advice and information to staff, parents and children and for carrying out any policies which have been agreed with the Consultant for Communicable Disease Control (CCDC). General practitioners, other primary care staff and pharmacists have a responsibility to be knowledgable and competent in the control and prevention of head lice, and to advise and educate the public accordingly. They should never advise treatment unless they are convinced (preferably by physical evidence, such as a louse stuck on paper with clear adhesive tape) that live lice are present on the scalp of the person thought to be affected.

What are the most effective methods of control?

Successful control of head lice depends on accurate detection, adequate and appropriate treatment together with a check of the heads of all possible contacts. The only reliable method of diagnosing current, active infection is by detection combing and cannot be made with certainty unless a living, moving louse is found (no matter how many louse eggs [nits] are seen, how many reported cases there are in the school or how bad the itch is). Chemical treatment with an insecticidal lotion (not shampoo) is the only method which has been clearly demonstrated to be effective. Reported cases of 'reinfection' or 'treatment failure' are most likely to be a result of misdiagnosis ('imaginary lice' or the presence of nits only), faulty treatment technique or failure to identify affected contacts. Although the effectiveness of the wet combing method using conditioner ('Bug Busting') has yet to be demonstrated as a means of control in the population it may work for an individual or a family. Used regularly on a continuous basis this method may aid in early detection and physical removal of lice.

What are the dangers of using organophosphates and insectides on children?

These products have been used successfully in the treatment of head lice, body lice and scabies for many years. Of all the many thousand applications prescribed and sold over the counter in the past 24 years there have been only 27 reports of adverse drug reactions (40 reactions, no deaths). All new information is constantly under review and, if used in accordance with the manufacurer's instructions, there is no evidence to date of any untoward or long-term adverse effects as a result of their use.