Visceral leishmaniasis is progressive. Males are infected more than females, most likely as a result of increased exposure to sandflies. Otherwise, occurrence is proportional to sandfly exposure. After the bite of an infected sandfly, the incubation period ranges from weeks to months. Systemic symptoms generally are absent.
Skin trauma can result in activation of cutaneous infection long after the initial bite.
The lesion usually evolves over time. Healed lesions leave an atrophic scar. Lesions can be pruritic or painful. Lesions caused by some species can heal without pharmacotherapy, but healing can take months. Mucocutaneous leishmaniasis Incubation period is from 1-3 months.