Clinical Endpoint Study of Ivermectin 0.5% Lotion

Inclusion Criteria

• Signed Institutional Review Board (IRB)-approved informed consent form that meets all criteria of current FDA regulations. For participants who are considered minors in the state the study is being conducted (<18 years in most states), the parent or legal guardian should sign the consent form and the child will be required to sign a participant "assent" form, as appropriate. Participants 11-17 years of age will read and sign an IRB-approved assent form and participants 6-10 years of age will provide verbal assent. Participants 6 months-5 years of age will be exempt from providing assent based on the child's comprehension and cognitive skills.
• The participant and/or the participant's parent (legal guardian) is willing to apply the study product as directed, comply with study instructions, and commit to all follow-up visits for the duration of the study.
• Male or non-pregnant, non-lactating female, 6 months of age or older.
• Females of childbearing potential must not be pregnant or lactating at Visit 1 (Day -1 to 1) (as confirmed by a negative urine pregnancy test with a sensitivity of less than 50 milli-international units/milliliter [mIU/mL] or equivalent units of human chorionic gonadotropin). Women of childbearing potential must agree to the use of a reliable method of contraception. (for example, total abstinence, intrauterine device, a double-barrier method, oral, transdermal, injected, or implanted non-hormonal or hormonal contraceptive) throughout the study. Female participants using hormonal contraceptives should have been on the same product/dosing regimen for at least 28 days before Visit 1 (Day -1 to 1) and should not change this regimen during the study. A sterile sexual partner is not considered an adequate form of birth control.
• Index participants (that is, the youngest household member) must have an active head lice infestation, defined as ≥3 live lice (that is, live adults and/or nymphs), at Visit 1 (Day -1 to 1).
• Household members participating in the study must have ≥1 live louse (that is; live adults and/or nymphs) at Visit 1 (Day -1 to 1).
• All members of the household must be present for examination. Any male head of household who is unable to attend Visit 1 (Day -1 to 1) may be assessed by a second member of the household as being lice free.

Exclusion Criteria

• Females who are pregnant, lactating or planning to become pregnant during the study period.
• Participants who do not have a known household affiliation with their household members (that is, do not stay in 1 household consistently, sleeping at 1 place several nights and then at another place or location). Household is defined as living in a shared area or space (for example the same house or apartment unit).
• Any infested member of the household is unable or unwilling to be treated with the study product. This includes male heads of household who do not attend Visit 1 (Day -1 to 1) but report infestation with lice.
• More than 3 members of the household infested with lice.
• Presence of visible skin/scalp condition(s) or open wounds at the application site that are not attributable to head lice infestation and that in the opinion of the Investigator will interfere with safety and/or efficacy evaluations.
• Presence of eczema or atopic dermatitis at the application site.
• Use of any prescription, over-the-counter, or home remedies for the treatment of head lice within 7 days before Visit 1 (Day -1 to 1).
• Use of pediculicides within 4 weeks before Visit 1 (Day -1 to 1).
• Use of systemic anti-parasitic agents within four weeks before Visit 1.
• Participants with very short (shaved) hair or who are planning to shave head during the study.
• Use of any hair dye, bleaches, hair straightening, or permanent wave solution on the hair within 14 days before Visit 1 (Day -1 to 1).
• History of allergy or sensitivity to pediculicides or hair care products.
• History of any drug hypersensitivity or