Leishmaniasis is a parasitic infection that is endemic in some areas of Latin America, the Middle East, North Africa, and the Mediterranean. Mucocutaneous leishmaniasis is one of the three main clinical types of the disease. Biopsy of the lesion or a swab should be obtained for microbiological testing in order to confirm the diagnosis.
With approximately 1.3 million infections and more than 50,000 deaths every year, leishmaniasis is an important infectious disease that has an endemic status in the majority of Latin America, countries of the Mediterranean basin, the Middle East, and certain areas of Africa and Asia [1] [2] [3] [4] [5] [6]. The protozoan parasite Leishmania, the causative agent of leishmaniasis, is transmitted to the human host by the sand fly vector from a number of animal hosts (or other human hosts that are already infected, in which case the term anthroponotic leishmaniasis is used) [1] [3]. Mucocutaneous leishmaniasis is one of the three clinical forms (in addition to visceral and cutaneous) of this parasitic infection, distinguished by the onset of lesions on the skin and on mucous membranes as well [1] [2] [3] [4] [7] [8]. Certain Leishmania species (L. braziliensis, L. major, L. panamensis, L. guyanensis, L. infantum, and L. donovani) are known for their propensity to produce mucocutaneous forms that start with the development of an erythematous papule at the site of the sand fly bite [1] [3]. The face and the extremities are usually the locations of the initial lesion, which can appear weeks or even years after the bite [1] [3]. Over time, the papule increases in size and eventually breaks, leading to the formation of a painless, well-demarcated ulcer [1] [3]. Spontaneous resolution within a few months is seen in the majority of cases, but new lesions might appear at various sites on the body [1] [3]. The distinguishing feature of mucocutaneous leishmaniasis is the mucosal involvement, predominantly in the oral cavity and the nasopharynx [2] [8].
A thorough clinical approach is necessary in order to make the diagnosis of mucocutaneous leishmaniasis. A meticulously obtained patient history should be the first step, during which the physician must bear in mind the country of residence and travel to endemic areas in the past several years, whereas a history of sand fly bites might be assessed as well. A properly conducted physical examination, with an emphasis on the inspection of the skin and the oral cavity, may be even more important for identifying the lesions seen in mucocutaneous leishmaniasis. To solidify clinical suspicion, however, several microbiological tests can be employed. Scrapings from the lesions are used for microscopic smear examination or cultivation, the former being a superior method due to the longer turnaround time of cultures (up to 10 days are necessary for Leishmania to grow on standard media) [3] [4]. A histological examination of a biopsy sample (using hematoxylin-eosin staining) can be carried out, but the introduction of serological and molecular studies have greatly improved the overall rate of diagnosis [3] [4]. The Montenegro's test, comprised of inoculating Leishmania antigen into the forearm, can yield conclusive results after 72 hours [3] [4] [8]. Polymerase chain reaction (PCR), although being expensive and more sophisticated compared to the previously mentioned methods, should be implemented whenever possible, primarily because of its very high sensitivity/specificity rates [3] [4] [9].