An open-label phase IV clinical trial of miltefosine, designed to evaluate intracellular and plasma drug pharmacokinetics in children and adults using a population pharmacokinetics design. Two study groups have been defined: 1) children 2-12 years of age (n=30) and 2) adults 18-60 years of age (n=30) with confirmed parasitological diagnosis of cutaneous leishmaniasis. The participants will receive supervised standard treatment with miltefosine: 1.8 - 2.5 mg/Kg of weight for 28 days.