WHO approval of a new Essential Medicine for dermatology – oral ivermectin
25 July 2019
In many regions of the world, particularly in tropical climates, endemic infection with scabies is the commonest reason for patients to seek dermatological care. The problem is compounded by poverty and household overcrowding to an extent that prevalence rates of infection in communities can be higher than 15%. Secondary infection and downstream consequences, such as streptococcal nephritis and rheumatic fever, are end results of endemic scabies . These factors led the World Health Organization (WHO) to designate scabies as a neglected tropical disease in 2017.
Current treatments for scabies with a variety of different topical medications from permethrin to benzyl benzoate to sulphur ointments may work well in many settings. But in areas with high endemicity (where prevalence rates exceed 10%), in older persons and in those with clinical variants of scabies, particularly crusted scabies where mite burdens are huge, require different measures. Increasingly the oral avermectin drug, ivermectin, has been shown to be the most suitable treatment for mass drug administration and complicated scabies. This has been backed by extensive field trials in Fiji  and other countries such as Ethiopia.
Access to treatments for scabies, as other medical conditions, is critically dependent on drug availability at the point of care. While many countries rely on national guidelines the list of essential medicines (Essential Medicines Lists or EML for adults and children) produced and revised every two years by the World Health Organization is a key resource for guiding countries to minimum requirements to ensure access to quality standards of care. The list contains over 100 medicines which are carefully selected after a rigorous adjudication by an expert panel and external referees, appointed by WHO, for efficacy, safety and cost-effectiveness.
As part of its ongoing work and representation of the needs of the dermatology community, the International League of Dermatological Societies (ILDS) WHO Committee has been liaising with WHO over Essential Medicines as part of its overall strategy for global health interventions. The EML subgroup on behalf of the ILDS and International Alliance for the Control of Scabies (IACS), an organisation set up as an alliance between dermatologists and other interested physicians and scientists, submitted a dossier to the Essential Medicines panel in 2018 for the approval of oral ivermectin as an essential medicine for scabies. It has been through the rigorous review process and in July 2019 was formally approved. Oral ivermectin is now listed on the Essential Medicines List from 2019 for use in human ectoparasite infestations .
Roderick Hay, Olivier Chosidow and Luigi Naldi
Advisors to the ILDS WHO Committee
- Engelman D, Kiang K, Chosidow O et al. (2013) Toward the Global Control of Human Scabies: Introducing the International Alliance for the Control of Scabies. PLoS Negl Trop Dis 7(8): e2167. doi:10.1371/journal.pntd.000216
- Romani L, Whitfeld MJ, Koroivueta J, et al. Mass Drug Administration for Scabies Control in a Population with Endemic Disease. The New England journal of medicine. 2015;373:2305-13.
- https://apps.who.int/iris/bitstream/handle/10665/325771/WHO-MVP-EMP-IAU-2019.06-eng.pdf?ua=1 (page 26)