Latency time in cutaneous leishmaniasis.

Latency period in cutaneous leishmaniasis was very rarely studied so far. We describe three patients, aged 71, 50 and 32 years, respectively, who contracted cutaneous leishmaniasis in Sicily. In all patients, clinical diagnosis was confirmed by histopathological examination and polymerase chain reaction: the latter was positive for Leishmania infantum in two patients and Leishmania canis in one. All cases were characterized by a very long period of latency, ranging from 11 to 16 months. These cases suggest that latency time of cutaneous leishmaniasis acquired in Sicily may be sometimes very long. The reasons of this latency time are unknown: latency depends neither by the involved species of sandflies and Leishmania nor by the immunological response of the patients: all laboratory tests, including immunological ones, were normal.