Ivermectin for Parasitic Skin Infections of Lice: A Review of Comparative Clinical Effectiveness, Cost-Effectiveness, and Guidelines

Context and Policy Issues

Pediculosis refers to a group of conditions that result from parasitic skin infestations of lice. Three species of lice typically infest humans: Pediculus humanus capitis (i.e., head lice), Pediculus humanus corporis (i.e., body lice), and Pthirus pubis (i.e., pubic lice). Lice are wingless, blood-sucking, obligate parasites that have no free-living stage in their life cycle., Adult lice are between 1 to 3 mm in length and can lay up to 300 eggs, or nits, during a lifecycle., Nymphs are hatched from eggs, and become full-sized adults approximately 10 days after hatching., Transmission between individuals typically occurs through head-to-head or body-to-body contact, contact with infested linen, brushes, or clothes, and in the case of pubic lice, sexual contact.,

Infestation with lice may result in discomfort, pruritus (i.e., itchy skin), substantial social distress, anxiety, embarrassment, and unnecessary absence from school and work., Although parasitic skin infestations of lice affect all socioeconomic groups, head lice predominantly infests schoolchildren between the ages of 3 and 14 in industrialized countries., Reliable data on the prevalence rates of lice infestation are not often available due to large regional variance (both between and within countries). However, it is estimated that there are between 6 million and 12 million head lice infestations among children every year in the United States, with an annual cost of treatment exceeding US$500 million.,,,

Many options for the treatment of lice infestation are available. These include both topical (e.g., shampoos, creams, oils) and oral agents. Historically, pediculocides have been used as a first-line treatment option; however, their extensive use has led to the development and spread of resistant lice.,, Ivermectin, a broad-spectrum antiparasitic agent available in both topical and oral forms, has been used as an alternative option for the treatment of lice infestation, especially in individuals who have experienced a treatment failure.

The purpose of the current report is to evaluate the comparative clinical and cost-effectiveness of oral ivermectin, topical ivermectin, and pediculicides for the treatment of parasitic skin infections of lice. Additionally, evidence-based guidelines regarding the use of ivermectin for parasitic skin infections of lice will be reviewed.