Pediculosis is an infestation of the skin, hair or genital region caused by small insects called lice, which live directly on the body or in garments. The lice are small wingless parasites with sucking mouth parts that feed on human blood and lay their eggs on body hairs or in clothing. Lice infestation itself is not dangerous but a serious public health problem because some lice can carry microorganisms that cause diseases like relapsing fever, trench fever and epidemic typhus.

Lice infestation usually occurs due to poor upkeep and hygiene of hairy body parts for want of adequate facilities for bathing and washing of clothes, particularly undergarments. Any individual could get lice infestation; children with long hair are however more prone to suffer.

The most common site for lice infestation is the scalp, and it is transmitted from one person to another by close contact and by sharing of combs and hair brushes. Head lice infestation in epidemic form is common in school-going children. Adult lice can be seen on the patient’s scalp close to the base of hairs and around the ears and these may spread from the scalp to the eyebrows, eyelashes, and beard in adults, although they are more often limited to the scalp in children. Grayish-white eggs called nits may also be visible along with lice. Nits are premature forms of lice, which take 3 to 14 days to hatch.

Infestations of body lice and pubic lice are seen in individuals who maintain poor personal hygiene, wear the same clothes and vests continuously without laundering, do not bathe regularly and share bedding or clothes or towels with infected persons. The common symptom of lice infestation irrespective of body location is itching, usually with injury to the skin caused by scratching or scraping. The itching may be intense, and may be followed by bacterial infection of skin that has been scratched open. The itching results from an allergic reaction to a toxin that is present in the saliva of the lice. Diffuse skin eruption or inflammation can result with repeated bites of lice.

Another common complication in head lice infestation is swelling or inflammation of the neck glands. Patients with body lice often have intense itching with deep scratches around the folds of shoulders, flanks or neck. The bites first appear as small red pimples but may cause a generalized skin rash. If the infestation is not treated, the patient may develop complications that include headache, fever, and bacterial infection with scarring. Pubic lice may sometimes produce small bluish spots on the patient’s trunk or thighs.

Prevention of lice infestation and re-infestation is tedious requiring avoidance of close contacts with infected persons, sharing of garments, towels, etc. and maintenance of adequate body hygiene is more important than the treatment. Local application of the paste of certain medicinal plants and medicated oils is in practice in India for the treatment of lice infestation.

Some commonly used formulations are documented in the Ayurvedic Pharmacopoeia and Ayurvedic Formulary of India. Dhattura paste is one such formulation that is widely used in rural areas because of its effectiveness in killing lice.

Dhattura (Datura metel Linn.)

Dhattura is a popular medicinal plant of India documented for its anti-lice efficacy in the classical Ayurvedic literature. Bhavamishra describes the use of Dhattura seeds for the treatment of Yuka (lice) and Liksha (nits). The plant is enlisted in the Ayurvedic Pharmacopoeia of India2 providing pharmacopoeial standards and uses of the whole plant and seeds.

Dhattura plant grows as a weed throughout India. The plant is an erect and succulent annual herb or shrub about one metre in height with often purplish branches and triangular ovate leaves, bell-shaped flowers having purplish colour outside and white inside and round, thorny fruits. Dhattura seeds are light brown to yellowish brown in colour, odourless, kidney shaped, about 0.6 centimetre in length and 0.4 centimetre in width, compressed, flattened and thickened towards the curved edge with a bitter and acrid taste.

Composition

The paste for application over lice-infested parts consists of Dhattura seeds.

English name	Thorn apple
Latin name	Datura metel Linn.
Family	Solanaceae
Part used	Leaf and seeds

Main chemical constituents

Tropane alkaloids such as hyoscyamine, atropine, scopolamine, etc. and fixed oil.

Quality standards

Quality of Dhattura is estimated on the basis of the following physical constants.

Foreign matter	Not more than 2%
Total ash	Not more than 6%
Acid insoluble ash	Not more than 1%
Acid-soluble extractive	Not less than 5%
Water-soluble extractive	Not less than 7%

Method of preparation

• (1) Fresh mature leaves of Dhattura are plucked and ground in a mortar or grinder with a little water. The juice is expressed from the ground leaves for application the same day.
• (2) For making a paste, dry seeds are first finely powdered and then mixed properly with an equal amount of water or mustard oil.
• (3) Adding mustard oil to the leaf juice or seed powder enhances the anti-lice effect of Dhattura.
• (4) The body-part, where juice or paste of Dhattura is to be applied should not be wet and it is better to use the medicament at night to derive optimal effect.

Dosage form

Greenish juice of leaves and yellowish-brown oily powder of seeds.

Therapeutic properties

Dhattura is known to have strong nematicidal, analgesic, anti-viral, anthelmintic and anti-spasmodic properties by virtue of which it is useful in treating lice infestation and associated symptoms.

Dose and mode of administration

• (1) The amount of leaf juice or seed powder required for application depends upon the size of the affected area. Usually 25 to 30 millilitres of leaf juice or paste of seeds, 5 to 10 grams, made with 15 to 20 millilitres of water or mustard oil is required for a single application on the scalp. The paste of powdered seeds is preferred over leaf juice in case lice infestation is confined to the head.
• (2) Fresh juice of Dhattura leaves or paste of seeds is to be applied uniformly over the affected area with hands and left for at least three to four hours and then washed with plain water. The juice or paste should be applied against the direction of hairs to provide maximum exposure to the insects. The longer the medicine remains in contact with the body, the better the results seen. Due care must be taken to ensure that the medicine is applied close to the base of the hair on the scalp and other parts of the body.
• (3) Washing the hair with shampoo before or after applying the medicine should be avoided as it dilutes the medicine’s effectiveness.
• (4) Dead lice or nits should be removed manually or with a comb after the paste or juice has dried.
• (5) Application of Dhattura leaf juice or paste of seed powder should be done consecutively for three to five days till all lice and nits are killed and removed. Further hair wash should be done at least two days after the completion of the course of treatment.

Indications and uses

Lice infestation with or without nits in the head, pubic and other regions of the body and associated symptoms of itching and skin rash is the main indication for the use of Dhattura paste or juice on affected parts.

Precautions and safety aspects

It is important to observe the following precautions:

• (1) Dhattura is a poisonous medicinal plant and hence it should be used with care.
• (2) While applying or removing leaf juice or seed paste of Dhattura, due care must be taken that the medicine does not get into the eyes, mouth, ear, nose and other natural openings of the human body.
• (3) Remove the dead or partially inactivated lice with a narrowtooth comb or manually.
• (4) Mixing Dhattura medication with other drugs with similar action is not desirable as drug to drug interaction is unknown.
• (5) The most important step in treating head lice infestation is to treat the person and other family members simultaneously with medication to kill the lice and prevent re-infestation and cross-infection.
• (6) Wash clothes and bedsheets used by the infested person two days before the treatment is started.
• (7) The lice-infested person should wear clean clothing after each application of Dhattura medication.
• (8) In case a few live lice are found after two to three applications of medicine, but are moving more slowly than before, there is no need for further treatment. Comb the hair to remove such lice and wait for a day or two for the medicine to kill the remaining lice on the head.
• (9) Whereas no dead lice are seen and lice are as active as before, the medicine may not be working. In such a situation seek medical opinion and follow doctor’s advice.
• (10) After a course of 2-3 days treatment, check the hair bases and comb hair with a nit-comb to remove nits and lice on alternate days. Continue to check for 2 to 3 weeks until it is assured that all lice and nits are killed and removed.
• (11) To kill lice and nits present in the clothing and bed linen that was used during two days before treatment, wash them using hot water with not less than 130°F temperature or dry laundry using high heat for at least 20 minutes. Similarly, combs and hair brushes should be dipped in hot water and washed with soap.
• (12) Clothes such as coat, scarf, cap, etc. should be dry cleaned.
• (13) In order to prevent re-infestation, all such activities should be avoided that are likely to spread lice such as head-to-head contact during play and at home; sharing of clothes and towels, hair brushes and combs; and lying on beds, sofas, couches, pillows, carpets, or stuffed animals that have recently been in contact with an infested person.

References

• (1) Chunekar KC. Bhavaprakasha Nighantu. Edited by Dr GS Pandey. Varanasi: Chaukhamba Bharati Academy, 1999. p. 317-320.
• (2) India, Ministry of Health and Family Welfare. The Ayurvedic pharmacopoeia of India. Part I. Vol. III. New Delhi: Department of Indian Systems of Medicine & Homeopathy, 2001. p. 43-44.
• (3) India, Ministry of Health and Family Welfare. The Ayurvedic pharmacopoeia of India. Part I. Vol. III. New Delhi: Department of Indian Systems of Medicine & Homeopathy, 2001. p. 44.
• (4) Sharma PC, Yelne MB, Dennis TJ. Database on medicinal plants used in Ayurveda. Vol. 2. p New Delhi: Central Council for Research in Ayurveda & Siddha, 2001. 203.

Further reading

• (1) U. S. Department of Health and Human Services, Centers for Disease Control and Prevention, Division of Parasitic Diseases. Web site http://www.cdc.gov/ncidod/dpd/index.htm (accessed 21 February 2010).
• (2) Kurup PNV, Ramadas VNK, Joshi P. Handbook of medicinal plants. New Delhi: Central Council for Research in Ayurveda and Siddha, 1979.
• (3) Nadkarni AK. Dr K.M. Nadkarni’s Indian materia medica. Vol. I. Bombay: Popular Book Depot, 1976.
• (4) Sharma PV. Classical uses of medicinal plants. Varanasi: Chaukhambha Visvabharati, 1996.
• (5) Sharma PV. Dravyaguna vijnana. Vol. II. Varanasi: Chaukhamba Bharati Academy, 2001.
• (6) India, Ministry of Health and Family Welfare. The Ayurvedic pharmacopoeia of India. Part I. Vol. IV. New Delhi: Department of Indian Systems of Medicine and Homeopathy, 2004.

Source: Traditional Herbal Remedies for Primary Health Care - WHO