The diagnosis in our case was challenging, as none of the above findings were seen in our patient. The specimen taken by the border patrol medical provider was negative on Gram, Giemsa, and Grocott-Gömöri methenamine silver staining; no amastigotes were identified. Another diagnostic modality (not performed in our patient) is the Montenegro delayed skin-reaction test, which often is positive in patients with cutaneous leishmaniasis but also yields a positive result in patients who have been cured of Leishmania infection.6
An important consideration in the diagnostic workup of leishmaniasis is that collaboration with the CDC can be helpful, such as in our case, as they provide clear guidance for specimen collection and processing.2
Treatment—Treating leishmaniasis is challenging and complex. Even the initial decision to treat depends on several factors, including the form of infection. Most visceral and mucocutaneous infections should be treated due to both the lack of self-resolution of these forms and the higher risk for a potentially life-threatening disease course; in contrast, cutaneous forms require further consideration before initiating treatment. Some indicators for treating cutaneous leishmaniasis include widespread infection, intention to decrease scarring, and lesions with the potential to cause further complications (eg, on the face or ears or close to joints).6-8
The treatment of choice for cutaneous and mucocutaneous leishmaniasis is pentavalent antimony; however, this drug can only be obtained in the United States for investigational use, requiring approval by the CDC. A 20-day intravenous or intramuscular course of 20 mg/kg per day typically is used for cutaneous cases; a 28-day course typically is used for mucosal forms.
Amphotericin B is not only the treatment of choice for visceral leishmaniasis but also is an important alternative therapy for patients with mucosal leishmaniasis or who are co-infected with HIV. Patients with visceral infection also should receive supportive care for any concomitant afflictions, such as malnutrition or other infections. Although different regimens have been described, the US Food and Drug Administration has created outlines of specific intravenous infusion schedules for liposomal amphotericin B in immunocompetent and immunosuppressed patients.8 Liposomal amphotericin B also has a more favorable toxicity profile than conventional amphotericin B deoxycholate, which is otherwise effective in combating visceral leishmaniasis.6-8
Other treatments that have been attempted include pentamidine, miltefosine, thermotherapy, oral itraconazole and fluconazole, rifampicin, metronidazole and cotrimoxazole, dapsone, photodynamic therapy, thermotherapy, topical paromomycin formulations, intralesional pentavalent antimony, and laser cryotherapy. Notable among these other agents is miltefosine, a US Food and Drug Administration–approved oral medication for adults and adolescents (used off-label for patients younger than 12 years) with cutaneous leishmaniasis caused by L braziliensis, L panamensis, or L guyanensis. Other oral options mentioned include the so-called azole antifungal medications, which historically have produced variable results. From the CDC’s reports, ketoconazole was moderately effective in Guatemala and Panama,8 whereas itraconazole did not demonstrate efficacy in Colombia, and the efficacy of fluconazole was inconsistent in different countries.8 When considering one of the local (as opposed to oral and parenteral) therapies mentioned, the extent of cutaneous findings as well as the risk of mucosal spread should be factored in.6-8
Understandably, a number of considerations can come into play in determining the appropriate treatment modality, including body region affected, clinical form, severity, and Leishmania species.6-8 Our case is of particular interest because it demonstrates the complexities behind the diagnosis and treatment of cutaneous leishmaniasis, with careful consideration geared toward the species; for example, because our patient was infected with L panamensis, which is known to cause mucocutaneous disease, the infectious disease service decided to pursue systemic therapy with amphotericin B rather than topical treatment.