Fun and Education

Yingshan Shi, MD (773) 702-6169 Started on Jan. , 2003, updated on June 27, 2009

Head Lice

Parasite	Cause	Routes of transmission	Diagnosis	Treatment
Head louse Lice	Pediculus capitis Only in human head hair Egg: take 7-10days to hatch Nit: persistent empty egg shells, Can stand for months Nymph: day 11-22, take at least 6 blood meals/d Adult: live weeks sesame seed to 3mm translucent to black lay 5-6 eggs daily Hatching to laying egg Total 10days live 6-20 hours after removed from the hosts Killed eggs or nit can attached to the hair for months	Most-Head to head close contact Less likely-by fomites such as combs, scarves, Hairbrushes, hats, headphones, cuddly toys, sport fear, sofa Risk factors Girls more close play Loosely ponytail Socially active All ethnic group	Find a living louse By using a plastic, fine-toothed comb with a gap< 0.3mm Dry comb- wiped on a wet paper towel- 50% more effective than scalp inspection by parting the hair Check regularly for 4-6weks Check household members Killed eggs or nit can attached to the hair for months	Combing out lice, viable eggs & nits Pediculicides Give when find live lice to avoid resistance All pediculicides Against lice in all stage. Activity against louse eggs is unpredictable Anything an infected patient touches should be dry cleaned, hot washed, sealed in plastic for 2 weeks and /or vacuumed. Some hair conditioners and hair treatment may reduce the quantity of permethrin

Approved Pediculicides for Lice Treatment

Traditionally: Lindane, malathions, natural permethrins, such as RID A200

Newer agents: 1% permethrin (Nix), anise and HairClear 1-2-3(Quantam), herbal product

FDA Approves Benzyl Alcohol Lotion for the Treatment of Head Lice on April 9,2009

http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm149562.htm

Product Application Comments

1^st line medications

1% permethrin Apply to damp hair, thoroughly towel Do not use crème rinse conditioners or shampoo/

(Nix) dry scalp for 10 minutes and rinse out conditioner combination products prior to use the Nix

Liquid crème rinse (may coat and protect nits). Although Nix is ovicidal,

Some recommend a 2^nd treatment in 7-10days (The

eggs usually hatch/grow to full-size lice within 9 days).

Pyrethrins Shampoo with product to wet hair Repeat application in 7-10days. Follow specific

(RID, A-200, Barc for 10 minutes and then rinse. Product package insert.

Clear, Pronto, others) Gel, liquid, mousse, shampoo

2^nd line medications

Malathion Apply to dry hair until wet. Allow to 2^nd application may be necessary in 7-9 days of live

(Ovide) dry naturally and remain in uncovered lice remain.

0.5% lotion hair for 8-12 hours, then shampoo * Very flammable- not near dryers, around heating

regularly. sources

Lindane Lotion: Apply to dry hair and remain in Do not use oil-based grooming products for several

1% shampoo Place for 12 hours, then shampoo days prior (may increase absorption). Avoid contact

regularly. With mucous membranes and non-intact skin.

Keep out of reach of young children

Shampoo: apply to dry hair using a

small amount of water to produce a Not use for the children < age 2

Good lather, and rinse after 4 minutes. * Precaution for various neurological problems

Check hair 8-12 hours after treatment. Comb out dead lice and debris .

Treatment Failure? The most common reason is improper use of medication

· Verify a correct diagnosis

· Check appropriate use the products- application time, to wet or dry hair, or prior use of hair conditioning

· Treatment of close contacts?

· Clean every thing an infected patient touches?

· Empty eggshells or eggshells containing killed embryos alone do not indicate active infection.

· Applying Pyrethroids and Pyrethrins seven days apart are safe and typically effective

· "No nits" polices are "ridiculous".

Treatment for Resistant Lice

Inf. Dis. In Children 4/2002, 1/2003

· Increase treatment time of permethrin from 10 minutes to overnight

· Increase concentration of permethrin from 1% to 5%

· Use alternative agents with less demonstrated resistance such as malathion.

· Use of TMP-SMX in addition to topical agent. (The research found that TMP-SMX and Permethrin 1% produced cure rate 95% vs. Permethrin alone 79.5%.

· Addition of mechanical or occlusive agents to remove or suffocate lice such as combing, vinegar or formic acid rinse, mayonnaise, petrolatum or chitin dissolving enzymatic shampoo.

· Ivermectin (oral200mcg/kg single dose) (Concerns regarding possible neurotoxicity in children since Ivermectin has shown serious central nervous symptom effects in animals when given in large doses. It is not indicated for this use, and the PDR recommends if not be used in children<15 kg).

· General Consideration:

- Know the resistance profile in specific areas. Possible lice susceptibility testing may be warranted as is presently done for other infectious agents.

- Application of the principle of rotational treatment or simultaneous treatment with multiple agents that work via different mechanisms may offset further resistance.

- Good cleansing of fomites and good contact tracing.

Insecticide	Brands Product form Dosage Correct Use
OTC Permethrin 1.0% Pyrethrum 0.3-0.33% with piperonyl butoxide 3-4%	NIX Crème rinse 1 application* **to dried hair RID, Clear, Pronto, Shampoo or mousse 2 applications to dry hair A-200, mousse is extremely 7-10days apart Various generics good at killing eggs
Rx Malathion 0.5% Lindane 1.0% Permethrin 5.0%	Ovide Alcoholic lotion 1 application to dry hair Various generics Shampoo or lotion 1 application* to dry hair Elimite Cream 1 application ** to dried hair
*A second application is required routinely after 7 days, also be necessary for other products ** Wash hair with a toiletry shampoo-rinsing-partially towel dried-apply the crème rinse 1. Treated with appropriate product, ensuring that the entire scalp and hair close to it are saturated. 2. In the most cases, it is not necessary to treat long hair further away from the scalp. 3. For most people, it is necessary to use at least one 2 oz bottle of product for a single application 4. The most important that the preparation is left on for the full time stated in the instructions. Avoid overexposure 5. Read the product instruction completely and to follow them exactly-apply to dry hair or partially tried hair 6. More efficient to apply a few drops at a time directly to the scalp and work systematically around the head to ensure even distribution 7. After washing off the preparation, remove nits by using the in-pack comb or a finger and thumbnail 8. In general, special cleaning home procedures are not required because lice do not voluntarily leave their hosts and, if they are physically detached, they die rapidly. 9. Using a plastic, fine toothed comb during the 7-day period after treatment. If find tiny fist or second developing lice, a 2nd application may be required for any product, no early than 7days, but no later than 10days after the 1^st ^application. 10. After the treatment has been completed, regular follow up checks should be performed by scalp examination and combing once a week for 4-6 weeks.