Use of the intramuscular route to administer pentamidine isethionate in Leishmania guyanensis cutaneous leishmaniasis increases the risk of treatment failure.

Background: New world cutaneous leishmaniasis (NWCL) can be found in French Guiana as well as in several other parts of Central and South America. Leishmania guyanensis accounts for nearly 90% of cases in French Guiana and is treated with pentamidine isethionate, given by either intramuscular or intravenous injection. The military population is particularly exposed due to repeated missions in the rainforest.