Water, Sanitation, and Hygiene (WASH) and One Health Determinants of Skin Neglected Tropical Diseases: A Scoping Review

Skin-related neglected tropical diseases (skin NTDs) represent a major global public health burden, affecting more than one billion people worldwide, predominantly in low- and middle-income countries. These conditions—including Buruli ulcer, cutaneous leishmaniasis, leprosy, lymphatic filariasis with skin manifestations, mycetoma, chromoblastomycosis, scabies, tungiasis, yaws, and others—are associated with substantial morbidity, chronic disability, stigma, and social exclusion. In recognition of this burden, the World Health Organization’s 2021–2030 NTD Roadmap prioritises integrated, cross-cutting strategies for skin NTD prevention and control, including water, sanitation, and hygiene (WASH) interventions and One Health approaches. WASH is widely recognised as a core pillar of NTD control; however, the evidence base linking specific WASH exposures and interventions to skin-specific NTD outcomes remains fragmented and poorly synthesised. Furthermore, many skin NTDs are influenced by complex ecological and environmental pathways involving human–animal–environment interactions, which are central to the One Health framework. Understanding how WASH practices intersect with environmental exposures, animal interfaces, and ecological determinants is critical for designing effective, context-appropriate interventions, yet no comprehensive mapping of this evidence currently exists. The purpose of this scoping review is to systematically map and characterise the existing peer-reviewed literature on WASH and One Health determinants of skin NTDs. Using a Population–Concept–Context (PCC) framework and guided by PRISMA-ScR methodology, this review will identify and describe: (1) associations between WASH exposures or interventions and skin NTD outcomes; (2) evidence relating to environmental, animal, and ecological factors relevant to WASH within a One Health lens; and (3) inclusive and enabling WASH considerations for individuals living with skin NTDs, including access, infrastructure, and self-care support. This review will include primary research studies of any design conducted in any geographical setting, provided they explicitly address WASH exposures or interventions in relation to skin NTDs and incorporate One Health–relevant dimensions. The findings will be synthesised descriptively and narratively, with results mapped by disease type, WASH domain, One Health component, study design, and geographical region. Expected outcomes of this scoping review include: 1. A comprehensive mapping of the current evidence base on WASH and One Health determinants of skin NTDs; 2. Identification of key knowledge gaps and under-researched domains; 3. Clarification of the scope, strength, and direction of reported WASH–skin NTD associations; and 4. Evidence-informed insights to support future research, policy development, and integrated programmatic approaches linking WASH, One Health, and skin NTD control. By making this protocol publicly available through OSF, this registration aims to promote transparency, reduce duplication, and support reproducible and methodologically rigorous evidence synthesis in the field of skin NTDs.