Self-healing in leprosy: A systematic review.

Background: Leprosy, caused by Mycobacterium leprae, affects multiple body systems and can lead to preventable disability if untreated. While multidrug therapy (MDT) has been available since 1982, historical evidence suggests that untreated leprosy can resolve spontaneously. Nevertheless, the prevalence of self-healing worldwide, as well as factors determining self-healing, remain unclear. Methods: A systematic review was conducted in 2023 with data from PubMed, Infolep, and Web of Sciences data bases, along with a google search. Data extraction and analysis followed PRISMA guidelines and were summarized in a separate Excel sheet. Included were English-language studies on self-healing in leprosy, regardless the year of publication. Results: We included six studies spanning from 1938 to 1978 exploring the incidence of self-healing in different countries and continents. Children, paucibacillary (PB) cases, and possibly males showed a higher probability of self-healing with an average healing time of two years. Discussion/Conclusion: Recent research on self-healing in leprosy is scarce and evidence limited. This is primarily due to ethical concerns regarding withholding effective treatment of diagnosed patients, and because of the absence of an agreed definition of self-healing. Nevertheless, self-healing appears to be a plausible phenomenon influenced by geographic and demographic factors, and the type of leprosy. We recommend further research on self-healing in leprosy, as it provides insight into the human immune system and the determinants of this phenomenon. More insight could help adapt clinical practices and public health strategies, thereby contributing to an effective management and control of this disease. Author summary: Leprosy, a chronic infectious disease caused by Mycobacterium leprae, presents significant health challenges worldwide, with the potential for avoidable disabilities if left untreated. While MDT has substantially reduced the disease burden since its introduction in 1982, historical records suggest that some cases of leprosy exhibit spontaneous resolution without medical intervention. However, the prevalence of self-healing globally and the factors influencing this phenomenon remain unclear. The review identified six studies conducted between 1938 and 1978, which examined the occurrence of self-healing in various countries. These studies revealed that children and individuals with PB leprosy demonstrated a higher likelihood of self-healing, typically within an average period of two years. Despite the limited recent evidence due to ethical considerations, self-healing appears to be a plausible phenomenon influenced by patient-specific characteristics and the type of leprosy infection. Ultimately, this paper presents a compelling case for future research on self-healing in leprosy, as it provides an interesting view on the human immune system as well as the determinants of this phenomenon. Our recommendations emphasize the necessity of such investigations to adapt clinical practices and public health strategies, thereby contributing to an effective management and control of this disease. [ABSTRACT FROM AUTHOR]