Young Migrant with Arm Ulcer

Case Description

A 26-y-old man with no significant history presented with a slowly growing painful ulcer on his forearm after an insect bite 2 mo prior. The patient had recently immigrated from Venezuela and had been traveling on foot through large areas of undeveloped jungle in South and Central America when his initial symptoms began. He denied any additional lesions or systemic symptoms. On physical exam, he was afebrile and well appearing with a solitary punched-out ulceration featuring dispersed granulation tissue and a well-defined, raised violaceous border (Figure 1). He had tender proximal lymphadenopathy. Initial laboratory study results were unremarkable.

Figure 1

Ulceration of proximal dorsal forearm. Courtesy of Dr Adam Roussas.

What Is the Diagnosis?

Cutaneous leishmaniasis

Management

The patient was admitted to the hospital for specialty consultation. Subsequent polymerase chain reaction testing confirmed the diagnosis of leishmaniasis. He was initially discharged on a course of oral fluconazole but subsequently returned due to incomplete resolution of the wound, requiring readmission for intravenous amphotericin B.

Discussion

Leishmaniasis is a protozoal infection transmitted by blood-sucking sandflies. Over 55,000 cases of cutaneous disease are reported annually in the Americas, with a fatality rate of 7%. ¹ The number of cases is likely underestimated due to underdiagnosis.^2,3 Although rare, endemic cases are reported in the United States. Many patients have no relevant travel history or known risk factors.^2,3 Cutaneous leishmaniasis can manifest with a wide range of symptoms, ranging from single, plaque-like eruptions to multisystem infection.^4,5 The diagnosis can be challenging. A thorough history and a high index of suspicion are important, especially as an increasing number of individuals from endemic areas migrate to the United States.

The incubation period of cutaneous leishmaniasis typically ranges from weeks to months following the initial exposure. ⁴ Localized cutaneous ulcerations are the most common clinical manifestations and can vary in size, number, and appearance. Patients with localized cutaneous leishmaniasis present with between 1 and 10 painless central craters with raised borders and either fibrinous exudates or dark eschars. ⁴ Lymphadenopathy and lymphangitis frequently coexist and may even appear prior to the eruption of cutaneous lesions.^4,5 While most cases of cutaneous leishmaniasis resolve with appropriate therapy, up to 10% of cases progress to nonlocalized forms.^4,5 The presence of more than 10 lesions or lesions involving 2 or more noncontiguous areas of the body should raise concern for disseminated leishmaniasis. ⁴ Isolated regions of tissue destruction on mucosal or mucocutaneous surfaces, particularly the naso-oropharynx, should raise concern for mucosal or mucocutaneous leishmaniasis. Systemic findings such as fever, malaise, and weight loss, with or without a history of cutaneous lesions, should raise concern for visceral leishmaniasis, which carries a 95% fatality rate if left untreated. ¹ Known worldwide as kala azar, visceral leishmaniasis has the second highest case fatality rate of any parasitic infection in the world.

The differential diagnosis for ulcerated skin lesions includes hematologic or lymphoproliferative malignancy, skin cancer, pyoderma gangrenosum, sarcoidosis, cutaneous anthrax, tuberculosis, nocardia, Kaposi sarcoma, and actinomycosis. Work-up for suspected leishmaniasis infection includes complete blood count with differential, basic metabolic profile, liver function tests, and HIV tests.^4,5 The physical exam should focus on the skin to adequately characterize cutaneous lesions, the naso-oropharynx and genital areas to assess for the presence of mucocutaneous lesions, and the lymphatic system to assess for associated lymphadenopathy. Hepatosplenomegaly, with the spleen typically more prominent than the liver, suggests visceral disease. ⁴

Appropriate treatment is dependent upon the severity of disease. Localized cutaneous infection can be treated with topical agents such as paromomycin or localized injection with stibogluconate or meglumine antimoniate.^4,5 Alternatively, oral agents, including the azoles and miltefosine, can be used either in isolation or in conjunction with topical therapy.^4,5 Cases of complicated leishmaniasis, including disseminated and visceral involvement, require treatment with intravenous antimicrobials. Treatment decisions should be made in conjunction with an infectious disease specialist. Close follow-up with a dermatologist or infectious disease specialist is recommended. Given the high morbidity and mortality, there should be a low threshold for admission for further evaluation if the diagnosis is not clear, especially for patients in vulnerable populations who might be lost to follow-up.

The GeoSentinel Surveillance Network Analysis demonstrated that anyone, migrant or traveler, who has been to an endemic region can develop leishmaniasis. ⁶ Cutaneous lesions are commonly ulcerative, nodular, or verrucous. Early identification and treatment can save lives.