The number of head lice infestations occurringannually in the United States is estimated at 6 millionto 12 million. Although a formal economicanalysis of head lice treatments has not been conducted,the direct cost of treatment can be roughlyestimated by considering the costs of pediculicidesand taking into consideration that patients may self-treatup to 5 times before seeking medical care.Added to the direct costs of treatment are indirectcosts because of lost school days and lost productivityand wages of parents who must stay home to carefor children who are sent home from schools thatemploy no-nit policies.
The cost of head lice infestation is tied to diagnosticand treatment practices. Research suggeststhat head lice infestations are frequently misdiagnosed.In addition, over-the-counter treatments areoften used incorrectly. The combination of misdiagnosisand improper treatment has contributed todecreased efficacy of pediculicides. This, in turn,further contributes to ineffective treatment and thenecessity for retreatment and related increases incosts. Lindane, a prescription pediculicide, is associatedwith serious safety concerns and is now recommendedfor use in selected populations only whenconventional treatment fails. Malathion 0.5% is theonly prescription pediculicide that is considered tobe safe and effective with no decrease in efficacyover time.
Managed care organizations, in collaborationwith school nurses and other healthcare providers,are working to promote more accurate diagnosis andproper use of pediculicides. The objectives of theseefforts are to make the treatment of head lice moreeffective and ultimately to lower the cost of treatmentby introducing better options early on.
(Am J Manag Care. 2004;10:S277-S282)
Direct and Indirect Costs
The associated direct and indirect costs oftreatment infestations in the United States isestimated to be hundreds of millions of dollarsper year.1-3 With an annual rate of up to12 million infestations in the United States,the costs associated with head lice infestationwere estimated at $367 million over adecade ago.1,4 Increased prevalence of infestationsamong the primary age group affected,children 3 to 12 years old, is likely toraise costs further.
Contributors to the cost of care includethe direct costs of treatment and severalindirect costs that are more difficult to quantify.Direct costs include the actual cost ofpediculicides or other treatments for controlof head lice. Most over-the-counter (OTC)products recommend 2 applications, butsome data suggest that patients self-treat anaverage of 5 times before seeking care froma healthcare provider, increasing the numberof OTC products purchased in anattempt to eradicate an infestation.5
Indirect costs include lost school andwork days when a child is sent homebecause of an infestation. A young child whois not allowed in the classroom because ofno-nit or zero-tolerance policies must becared for, often by a parent or guardian whois missing work. The potential lost wagesand productivity are difficult to accuratelyassess but may be significant. One sourcesuggests that lost wages alone may average$2720.3 Parents or guardians who cannotmiss work may have to hire a babysitter,which represents additional costs of care.Beyond the impact on families, schoolabsenteeism because of infestations mayresult in lost funding. No-nit policies contributeto absenteeism by promoting mandatoryexclusion of children who are found tohave nits. The least quantifiable indirectcosts are associated with unnecessary andimproper treatment, resulting in inadequatecontrol of lice. This may occur because ofincorrect diagnosis by a healthcare provideror because a parent who has heard of aninfestation within the school treats the childpreventively, even in the absence of lice ornits. Improper or unnecessary treatmentsare direct contributors to increasing treatmentfailures with pediculicides. This situationis similar to the emerging resistance toantibiotics that are improperly or unnecessarilyprescribed.
Effects of "Nonmanaged" Approach to Care
In a study of head lice diagnosis and managementaccuracy, samples of material thatwere considered by healthcare professionalsand the public to verify evidence of lice ornits were shown to contain a large proportionof materials that were not indicative ofinfestation.6 Only 53% of materials submittedas proof of infestation contained lice ornits, suggesting that about half of all diagnosesby this group were potentially inaccurate.Notably, among children attendingschools with no-nit policies, 73% were identifiedas having lice infestation, but only 39%of the samples from these children containedmaterial that supported a diagnosisof head lice. A comparison of results fromschools with and without no-nit policiesfound that children who were lice-free wereerroneously excluded from class more frequentlythan children with active infestations.These poor results confirm the needfor a managed approach to care that promotesaccurate diagnosis and appropriatetreatment.
Topical treatments include manualremoval (wet combing), homeopathic remedies,and OTC and prescription pediculicides.Wet combing and homeopathicremedies are described in Table 1. Peoplewho are concerned about side effects associatedwith pediculicides often promote theseoptions, but they are largely unproved orineffective.7 Homeopathic remedies generallyare not promoted as pediculicidal or ovicidal,although many laypersons believeincorrectly that applying occlusive agents,for example, will smother lice.7 Some productsare promoted for "removing" lice andnits, such as paw paw herbal shampoo anddiluted vinegar.8 Because homeopathicproducts are unregulated and therefore donot have to be tested before being marketed,their ingredients and concentrations can varysubstantially. Also, despite claims of "natural"ingredients, they may still produce local sideeffects, such as burning or irritation, andsome cause systemic toxicity if ingested.The paradox of increasing popularity andconsumer promotion of these unprovedapproaches to lice control illustrates the needfor guidance by healthcare professionals foreffective treatment of infestations.
Pediculicides that are available in OTCformulations include pyrethrin and permethrin.Piperonyl butoxide is also containedin pyrethrin products. Pyrethrin is generallyconsidered to be safe, although it may causemild skin irritation. Pyrethrin product labelingwarns against possible allergic reactionsin patients with ragweed allergies, but thereare no reports in the medical literature of thistype of reaction with the topical formulationof pyrethrin.4 However, topical pyrethrinproducts should not be used by patients whoare allergic to chrysanthemums.
Permethrin, a synthesized product relatedto pyrethrin, is available in a 1% rinse forpatients and in a 0.5% spray for inanimateobjects. Unlike pyrethrin, permethrin doesnot cause allergic reactions, although it maycause skin irritation. This product can beused for children older than 1 month, so it isconsidered to be relatively safe. Both permethrinand pyrethrin are pediculicidal but notovicidal, although resistance to each producthas been reported.5 Both products require asecond treatment 7 to 10 days after the firstto kill newly hatched lice.
As described in the article in this supplementtitled, "Clinical Update on Resistanceand Treatment of ,"resistance to OTC pediculicides is anincreasing problem. Resistance, along withinaccurate diagnosis and reliance on self-treatment,often results in overuse of permethrinand pyrethrin OTC products. This, inturn, leads to more resistance and less effectivetreatment options over time, as well asincreased costs of treatment. Resistance hasoccurred with some prescription products,too, underscoring the need for a more structuredand supervised approach to care.
Managed Care Approach. The managedcare approach to increasing the efficacy oftreatment while reducing the risk for resistanceinvolves promoting appropriate use ofOTC and prescription pediculicides. Topicalprescription products include permethrin5%, malathion, and lindane. Ivermectin, anoral medication, is used clinically, althoughit has not been approved by the Food andDrug Administration (FDA) for the treatmentof head lice. Prescription products andtheir attributes are presented in Table 2.
Permethrin 5%, which is not indicated forthe treatment of head lice, is sometimesused after treatment failure with permethrin1%. If treatment failure occurs due to resistanceto the lower concentration, however,the 5% concentration may not be effectiveeither.9
Malathion has both pediculicidal and ovicidaleffects and has been shown to kill licewithin minutes, although the package labelingstill lists an application time of 8 to 12hours.5 Flammability is a risk consideration,particularly when malathion is used to treatchildren. But no cases of burns associatedwith malathion have been reported to date,and it should be noted that other commonlyused products are also flammable, such asmost topical wart medications. Caregiversapplying malathion to a child should followlabel instructions in avoiding heat sourcesand should never smoke near the product.Among the public, a primary concernabout malathion is whether it poses a riskof toxicity. This concern appears to bebased on assumptions that low-concentrationmalathion for topical application carries thesame risk as agricultural-grade malathionused as a pesticide. There are substantial differencesin the malathion products producedfor human use versus agricultural useproducts. The malathion concentration inthe pediculicide is lower than that associatedwith systemic toxicity, unlike the significantlyhigher concentrations of malathionassociated with inhalation toxicity. No caseof toxicity associated with topical malathionused as a pediculicide has been reportedafter decades of human use.10 Based on itssafety and effectiveness, malathion is a keychoice in the managed care environment,particularly for generalized infestation, formost age groups. An additional advantage inusing malathion is that the patient does nothave to undergo multiple applications over 2weeks to eradicate lice and eggs.
Lindane, formerly marketed under thebrand name Kwell, was once a mainstay ofprescription pediculicides, but it is nowreserved as alternative therapy amongselected patients with intractable infestationsthat have not responded to conventionaltreatments. Lindane is now disallowedfor human use in California and in severalcountries outside the United States becauseit is associated with significant neurotoxicityin humans. The FDA has added warnings tothe product labeling about the risk of seizureand neurotoxicity associated with lindaneand has established restrictions for its use.11Lindane should not be used to treat childrenor small adults (<50 kg). Patients who havea lowered seizure threshold should not betreated with lindane, which is capable ofinducing seizures. Lindane also should notbe used to treat pregnant women because ofthe potential neurotoxic effects to an infantat the time of delivery. Immunosuppressedpatients should not be treated with lindaneunless their neurological status has beencarefully evaluated. Lindane is acutely toxic;accidental ingestion of just 15 mL may belethal. Lindane ingestion following a fattymeal increases the risk of neurotoxicity,since lipids enhance lindane exit from thegastrointestinal tract to the central nervoussystem. Deaths associated with lindane toxicityhave been reported. Physicians whoprescribe lindane should keep in mind thatthe patient is receiving a container with apotentially lethal dose if accidentally ingested.For these reasons, managed care organizationsgenerally should restrict the use oflindane. If lindane must be used, the pharmacistshould, according to product labeling,include a maximum of 60 mL per adultpatient and perhaps 30 mL for small children.Lindane is offered in 30- and 60-mLpackages. The pharmacist should dispenseonly the quantity needed for a single treatmentand should watch for repeat dispensingto an individual patient. By law, patientsmust be given a Medication Guide when lindaneis dispensed to promote safe use of theproduct. Given the extensive safety concernsabout lindane and the relatively highrate of resistance to the product, it should beused only in very selective cases.
If a patient cannot use a topical pediculicide,oral medication may be offered. Themost commonly prescribed oral agent isivermectin, an anthelmintic agent used totreat intestinal parasites and onchocerciasis.Ivermectin is not approved by the FDA for thetreatment of head lice but is a highly effectivepediculicide when administered at a dose of200 mcg/kg. It does not provide ovicidaleffects, however, so a second dose generally isnecessary in 7 to 10 days. Compliance withivermectin is high due to its simple dosingregimen. No resistance has been reported todate. Ivermectin is considered relatively safeand well tolerated, but it should not beadministered to children weighing less than15 kg. Ivermectin is rated as a pregnancy categoryC agent, so physicians should weighrisks versus benefits when deciding whetherto administer it to pregnant women. From amanaged care standpoint, ivermectin is anappropriate option after treatment failure withtopical pediculicides or with a particularlyintractable infestation.
Costs of Treatment
The cost of head lice control can be a factorin selecting a treatment regimen. Table 3presents costs of complete treatment for bothOTC and prescription products. As expected,OTC products are generally less expensive interms of direct costs, although patients whohave an insurance copay may obtain prescriptionproducts for less. Indirect costs arenot factored in, however. For example,although a course of treatment with permethrin1% may cost $30, compared with $46for malathion, the time associated with therecommended repeat treatment with permethrintranslates into an additional indirectcost. In a nonmanaged care environment,patients may use OTC products incorrectly,resulting in repetitive treatment andpotentially much higher total direct costs fortreatment.
Lice infestation is increasing, partlybecause of better reporting, but more significantlyas a result of documented increasesin resistance to pediculicides. Parents arefrustrated by the lack of efficacy of OTCproducts and are concerned about repeatedexposure of their children to pediculicides.In response, many have begun to use homeopathicremedies, believing that these willcontrol infestations effectively and moresafely than medication. Unfortunately, theseremedies are largely unproven.
A significant contributor to the increasein resistance is unnecessary and improperuse of pediculicides. Managed care, in coordinationwith school nurses and othertrained professionals, can offer much-neededguidance about the proper use of bothOTC and prescription products for the treatmentof head lice. A managed care approachto treatment would limit the use of OTCapplications to the recommended 2 applicationsand emphasize correct applicationprocedures, in contrast to the 4 or 5 applicationsoften used by patients. Using a managedcare approach, physicians couldquickly identify resistant cases and moveforward with prescription products. Mostimportant, managed care physicians canevaluate specific cases on an individual basisand initially determine the correct eradicationmethod. Currently, malathion is thefirst-line treatment of choice among managedcare organizations. This controlledapproach to care can improve treatmentefficacy, reduce resistance, and promotecost effectiveness.
The author wishes to acknowledge theassistance of Ronald C. Hansen, MD, in providinginformation about the economics ofhead lice treatments.
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