Hyperadrenergic postural tachycardia syndrome in mast cell activation disorders.

Postural tachycardia syndrome (POTS) is a disabling condition that commonly affects otherwise normal young females. Because these patients can present with a flushing disorder, we hypothesized that mast cell activation (MCA) can contribute to its pathogenesis. Here we describe POTS patients with MCA (MCA+POTS), diagnosed by episodes of flushing and abnormal increases in urine methylhistamine, and compared them to POTS patients with episodic flushing but normal urine methylhistamine and to normal healthy age-matched female controls. MCA+POTS patients were characterized by episodes of flushing, shortness of breath, headache, lightheadedness, excessive diuresis, and gastrointestinal symptoms such as diarrhea, nausea, and vomiting. Triggering events include long-term standing, exercise, premenstrual cycle, meals, and sexual intercourse. In addition, patients were disabled by orthostatic intolerance and a characteristic hyperadrenergic response to posture, with orthostatic tachycardia (from 79+/-4 to 114+/-6 bpm), increased systolic blood pressure on standing (from 117+/-5 to 126+/-7 mm Hg versus no change in POTS controls), increased systolic blood pressure at the end of phase II of the Valsalva maneuver (157+/-12 versus 117+/-9 in normal controls and 119+/-7 mm Hg in POTS; P=0.048), and an exaggerated phase IV blood pressure overshoot (50+/-10 versus 17+/-3 mm Hg in normal controls; P<0.05). In conclusion, MCA should be considered in patients with POTS presenting with flushing. These patients often present with a typical hyperadrenergic response, but beta-blockers should be used with great caution, if at all, and treatment directed against mast cell mediators may be required.

Estudio epidemiológico de leishmaniasis tegumentaria americana en Maypuco, Peru / Epidemiologic study of American cutaneous leishmaniasis in Maypuco, Peru

Se estudió la prevalencia de leishmaniasis tegumentaria americana en una localidad de selva baja en Loreto, Perú. En 67 sujetos (17,6% del total de la población) se determinó la hipersensibilidad cutánea (intradermorreacción de Montenegro) y el nivel de anticuerpos en el suero por el método de inmunofluorescencia indirecta. Ninguno de los reactores presentaba leishmaniasis activa en el momento de la prueba, aunque se observaron lesiones con cicatrices clinicamente compatibles con leishmaniasis tegumentaria americana en 4 de los 18 reactores (22,0%), lo que sugiere la importancia de la infección subclinica en la población estudiada. La intradermorreacción de Montenegro fue positiva en 26,8% de los sujetos estudiados y en 68,0% de los agricultores. Estos resultados sugieren que la infección no se adquiere en áreas pobladas y mas bien esta relacionada con ocupaciones desarrolladas en áreas alejadas, donde se encuentran el vector y los reservorios naturales