Pediculosis Lice are insects that live on human hair and clothing. They are small but can still be seen with the naked eye. Often they are well camouflaged and reflect the colour of the surroundings, which makes them difficult to see. The medical term for an infection or infestation with lice is called pediculosis. There are three types of lice that infest humans. Pediculus humanus var. capitis - The head louse Pediculus humanus var. humanus - The body louse. Phthirus pubis - The pubic louse. Lice are insects than live on rather than in the body. They are wingless and have six legs on which are attached strong claws, which they use to grasp on tightly to hair shafts or clothing fibers.

Head lice, the most common infestation in humans, their eggs are called nits. Pubic lice are smaller than the other two species, and have a short body resembling a crab.

Head Lice The most common lice infestation Outbreaks are common at schools and day care centers Infestations can be transmitted by close contact or share of personal items as caps, hair brushes,,,, Infestation with lice is quite often inappropriately considered related to poor hygiene and low socio-economic status. In fact people of all walks of life can get infested with lice and the stigma of catching lice is often borne out of ignorance.

Head lice lives in the scalp, a lice nit or egg is yellowish or grey in color, once it hatches it starts to feed. The nymph resembles the adult and matures with 9 days. Active and moves about the head. Adults are less active. The cycle may repeat every 3 weeks. The bite of the louse causes an immediate wheel to develop then a papule. Itching and scratching may result in infection Adults are difficult to see, but nits are spotted at the base of hair shafts (dandruff!!) Mostly in hair crown, near ears, the base of the neck

Body lice Infestation with body lice (Pediculus humanus) is uncommon. They tend to infest people in extreme states of poverty or personal neglect. Particularly when clothing is not changed or regular washing is not undertaken. The eggs of body lice are laid and glued to cloth fibers instead of hair, and the lice feed off the skin. Regular hot washing of clothes and bathing has lead to a decrease in incidence of body lice but during wartime and in some undeveloped countries the condition can still occur.

Body lice in the past have been responsible for spreading diseases such as typhus. However because of the decline in numbers of people infested with body lice this is no longer a significant problem. Similar insecticides used in the treatment of head lice are used in the treatment of body lice. Hot washing of clothes and bathing should be emphasised.

Pubic Lice Pubic lice or crabs are contracted by close contact and are easily transmitted sexually. The pubic hair is most common site but lice can spread to other hairy parts of the body including armpit, beard, chest hair and thigh hair. Eyelashes can also be affected. Pubic lice infestation results in itching. Blood specks on underclothes and live lice moving in the hair are occasionally noted.

Pediculosis Mortality/Morbidity: Morbidity results from the severe itching that is caused by lice infestation. Mortality may occur from infectious diseases transmitted by the body louse. Race: Blacks have a lower incidence of infestation by the head louse Sex: Males and females are equally at risk for infestation. Age: Lice affect all age groups. Body lice are indiscriminate in regard to the age of their host. Head lice are common in young school children but much less common after puberty. Pubic lice infest body and pubic hair.

Clinical presentation Patients may come to the attention of a health care provider after discovering lice or nits. Parents and teachers typically make the initial diagnosis of head louse infestation. Pruritus is the most common symptom of infestation. Children often have trouble sleeping because of intense pruritus at night when lice are feeding. Children with infestation may be asymptomatic. Routine nit inspections by school nurses are standard in many parts of the United States as well as in Jordan.

Physical: Manifestations of head louse infestation include scalp pruritus, occipital lymphadenopathy, and impetigo. Examination of the scalp reveals excoriations, dark specks of louse dung, nits, and adult lice.Pruritus commonly leads to excoriation, secondary bacterial infection, and regional lymph node enlargement. Pediculosis corporis: Body lice infest the seams of clothing and take feedings at night. Nits are found in the seams, not on human hairs. Pediculosis pubis: Pubic lice and nits generally are plainly visible throughout the pubic hair, extending onto adjacent hairy areas of the body. Eyelash nits are a manifestation of pubic louse infestation, not head louse infestation.

Treatment Non Pharmacologic Therapy Non of the pediculicides kills 100%. Visual inspection and combing with a nit comb is needed. Direct physical contact with the infested person should be avoided. Combs, brushes, and headbands should not be shared. Clothing and bedding should be washed in hot water and dried. Carpets, rugs and furniture should be well vaccumed. Shaving of hair is effective but not socially acceptable in most societies.

Treatment Pharmacologic therapy OTC treatment options include permethrin and synergized pyrethrins. Resistance probably has developed in many areas (overuse, misuse or insufficient contact time). Physicians in some countries select different pediculicides on a rotating basis to discourage development of resistance. A prescription only drug is 0.5% malathion

Malathion (Ovide. lotion) is a prescription drug approved by the U. S Malathion (Ovide* lotion) is a prescription drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of head lice infestation. The malathion lotion approved in the United States for the treatment of head lice is safe and effective when used as directed. Malathion lotion is both pediculicidal (kills live lice) and partially ovicidal (kills some lice eggs). The safety and effectiveness of malathion lotion has not been established by well controlled trials in children less than 6 years old.

Synergized pyrethrins Oleoresins obtained from chrysanthemum synergized by the addition of piperonyl butoxide (petroleum derivative). Approved for the treatment of head and pubic lice Pyrethrins block nerve impulse transmission causing insect paralysis and death. Piperonyl butoxide inhibits pyrethrin breakdown. 0.17-0.33% plus 2-4% of piperonyl but. Shampoo, foam, solution and gel. Not more than twice per 24 hrs Applied for 10 min then washed for 7-10 days Nit comb is needed

Pyrethrins have low toxicity. AE: irritation, erythema, itching and swelling. Contact with eyes and mucous membranes should be avoided

Permethrin Synthetic pyrethroid, acts of nerve cell membrane, causing paralysis. Systemic absorption from scalp takes place Used for head lice only, 1% cream is to be applied on the scalp, leave for 10 min, wash, comb with lice comb. Has residual effect for 10 days A.E.: transient pruritis, burning, stinging, irritation of the scalp. Avoid contact with eyes and mucus membranes. Not to be used in infants younger the 2 years.

Medical/Legal Pitfalls: Pyrethrin products are contraindicated for patients with contact allergy to ragweed or turpentine. Failure to recognize that pubic lice in children may be an indication of sexual abuse is a potential medical/legal pitfall. Children with eyelash nits have been exposed to an adult with pubic lice. This is not proof of abuse, merely an indication that the child has had contact with an adult with pubic lice. Pubic lice commonly infest the adult's body hair, as well as pubic hair. Although lice can be transferred easily in the absence of abuse, examine patient for other signs of abuse

Important points on treatment for pubic lice It is important to apply the shampoo to all hairy parts of the body apart from the eyelids and scalp - from 'neck to knees'. It is easily applied while in the shower. Work thoroughly into lather and leave on for five minutes. Rinse off thoroughly and dry with a towel. A repeat application is advisable 7 days later. Shampoo should not be applied near the eyes. Petroleum jelly, such as Vaseline can be smeared on the eyelashes twice a day for at least 3 weeks. Wash underwear and bed linen thoroughly in hot water to prevent recurrences. Sexual partners need to be treated even if they deny itching and do not appear to be infected. You may be at risk of other more serious sexually transmitted infections. It is advisable to attend your doctor or sexual health clinic for a check-up.

THANKS Please Take Care Head lice. 'Nits' (empty egg cases) adhere strongly to the hair shafts.