The purpose of this study is to determine the pharmacokinetics of miltefosine in children and adults with cutaneous leishmaniasis in plasma and intracellularly, and its relation with the parasitologic response. The results will provide pharmacologic bases to optimize the use of miltefosine for the treatment of cutaneous leishmaniasis, and will provide the knowledge base to assess the impact of pharmacokinetic behavior in children and adults on the emergence of drug resistance.