<23-year-old man presents to the clinic with a rash in his left foot. He is originally from the highlands of Peru and had spent the previous 2 months visiting some family there. They went hiking and rafting multiple times. Although his home had well water, he states he only drank bottled water during his trip. He has no medical problems. He is not sexually active and does not use intravenous drugs. He denies current fevers, chills, or night sweats. The rash is pictured
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Correct Answer: Bartonella bacilliformis
This patient most likely has South American bartonellosis, a disease endemic to the Andes mountains of Peru, Colombia, and Ecuador, caused by Bartonella bacilliformis.
- Intracellular, pleomorphic, gram-negative organism transmitted by the bite of a sandfly (Lutzomya spp.) and typically causes a biphasic disease.
- Initial, acute phase, known as Oroya fever, is characterized by fever, pallor, malaise, painless hepatomegaly, and lymphadenopathy.
- Oroya fever is diagnosed by blood cultures or Giemsa-stained peripheral smear.
- A minority of patients (<5%) can then progress to an the second stage “eruptive phase” (verruga peruana) weeks to months after recovering from the initial symptoms.
- Eruptive phase is characterized by hemangioma-like lesions in the skin and mucous membranes. This is diagnosed based on clinical suspicion.
- Importantly, most patients who present during the eruptive phase do not report an antecedent febrile illness.
- The preferred treatments for this disease are ciprofloxacin (combined with ceftriaxone if severely ill) during the acute phase and azithromycin for the eruptive phase.
Distractor answer choices
- Bacillary angiomatosis is typically seen in patients with HIV. It causes vascular lesions similar to kaposi sarcoma most frequently in the skin, although it can also affect the respiratory tract, bone, lymph nodes, GI tract, or brain. It is caused by infection with Bartonella henselae or quintana
- Bartonella hanselae is the most common etiologic agent of cat-scratch disease, which generally presents with a localized cutaneous lesion and regional lyphadenopathy
- Bartonella quintana is associated with “trench fever”, typically producing fevers, malaise, bone pain (particularly in the shins), nausea, and splenomegaly. A classic fever patterns is described with 5 days of fever followed by 5 day asymptomatic period(“quintan fever”). Disproportionately effects homeless patients, especially those with chronic alcoholism.
- Yaws is an endemic trepanomatoses caused by Treponema pallidum subspecies pertenue. Yaws commonly presents from the tropics, affecting children and presenting with infection of the lower extremities. Skin lesions begin as painless papules than can progress in weeks-months into an ulcerating nodule and then involve the bone if left untreated.
Author: Mauricio Kahn
Other Resources
Review of Bartonellosis (Carrion’s disease).
This question was uploaded on 4/13/22