**4. Disease presentation: clinical symptoms**

ZCL is characterized by a painless skin ulceration, which is an erythematous papule that becomes darker and develops a crust in the center over the course of several weeks. The lesions at the site of inoculation are usually situated on exposed areas such as the face and extremities, ranging from benign self‐limited cutaneous sores to more protracted and extensive lesions that may cause severe disfigurement. Generally, these lesions are self‐healing within 4–6 months.

It has been shown by several Tunisian epidemiological studies that the majority of human infections by Leishmania parasites remain asymptomatic, especially in endemic areas, indi‐ cating a high level of immunity of the residents in these regions [30]. Asymptomatic *L. major* infection constitutes a relatively frequent mode of natural immunization, and the ratio of asymptomatic infection to patent ZCL may reach approximately one‐third, especially in the context of low transmission rates [30].
