HeadLice.Org Hot Spots

Response to Commentary on: Head lice: boring for doctors, important to patients

Bailey AM & H. Phillip Petersen. Head lice: update on biology and control. (electronic response letter) eBMJ 12 June 2003


Head Lice: update on biology and control                       12 June 2003

*Anita M. Bailey & H. Phillip Petersen,

*Independent researcher

C/O Microbiology & Parasitology Dpt, University of Queensland, St Lucia 4072, Australia


Email Anita M. Bailey, et al.:


Editor, recent lice articles, including 'BestTreatments'1, need updating. Without serious medical investigation, head lice advice has sometimes relied on speculation from a few entomologists. For example, advice to avoid hair-cutting originated from a well-meaning but baseless suggestion in the 1970's.


Resistance to pediculicides is well-documented. Over-reliance on insecticidal treatment is putting children's health at risk. Non-drug measures should be recommended. Unchecked transmission in schools is causing higher prevalence. Routine screening is advised. Without it, treatment decisions should take into account repeated exposure.2,3


Head lice are not harmless. They can cause dermal injury and sensitization. Some people resort to household poisons to relieve persistent cases. A disproportionate amount of family time and money is wasted. Millions are spent in each of the UK, USA and Australia on louse treatment annually.3


Detection and removal of lice in some hairstyles is more difficult than previously thought. Our group has confirmed life-stage sizes as small as 0.6mm. Louse camouflage and various hair factors can cause false negatives and underestimations. Without such knowledge, clinical product assessments are questionable.4


Those who use a tiered diagnostic approach to screening have found that manual treatment is more successful than chemical. Fine-toothed combing is so helpful that it is one of the tools by which therapies are better assessed. Perhaps only head-shaving and microscopic examination are the gold standard.2,3,4


Dry-hair parting with a lamp-magnifier can help practitioners to identify continuous egg deposition at the scalp-hair margin outwards of chronic cases. Old 'nit' removal facilitates examination. Patients who remove eggs may also find hidden lice. Further fine-combing may helpfully confirm the live lice.2,3,4


Removed head lice are alive but probably less of a concern than direct transmission or unrecognized relapses. Longer or thicker hair impedes detection and removal of resistant infestations. Hair-shortening improves comfort and access to residual lice. Pediculosis is not self-limiting and undetected failures (some relapsing monthly for years) are common in longer hair of girls.3


Lice can transfer instantly across hair tresses with a vigorous rub. Severely neglected head lice may also bite further down the body. New biological findings place head and body lice in the same species. Body lice carry typhus, relapsing fever and trench fever, which are reemerging overseas. We suggest that pediculicides should be reserved to assist with control of such outbreaks. Lack of thorough screening and treatment will allow more resistant lice to proliferate.5


1.        Nash B. Treating head lice BMJ 2003; 326: 1256-8.

2.        Bailey AM, Prociv P. Persistent head lice following multiple treatments: Evidence for insecticide resistance in Pediculus humanus capitis. Australas J Dermatol 2000; 41: 250-54.

3.        Bailey AM, Prociv P. Pediculus humanus capitis infestations in the community: A pilot study into transmission, treatment and factors affecting control. Australian Infection Control 2001; 6: 95-101.

4.        Bailey AM, Prociv P. Head lice appearance and behaviour: implications for epidemiology and control. Australian Infection Control 2002; 7: 62-71.

5.        Bailey AM, Prociv P, Petersen HP. 2003. Head lice and body lice: shared traits invalidate assumptions about evolutionary and medical distinctions. Australian Journal of Medical Science 2003; 24: 48-62.


Competing interests: None declared


The National Pediculosis Association,® Inc.
A Non-Profit Organization
Serving The Public Since 1983.

The National Pediculosis Association is a non-profit, tax exempt
organization that receives no government or agency funding.
Contributions are tax-deductible under the 501c(3) status.

© 1997-2009 The National Pediculosis Association®, Inc. All images © 1997-2009 The National Pediculosis Association®, Inc.