Mordedura por Philodryas chamissonis: Presentación de un caso y revisión de la literatura

Abstract

Snake bite by Philodryas chamissonis: a case presentation and literature reviewThere are two species of snakes associated with snake bite poisoning in Chile: Philodryas chamissonis and Tachymenis peruviana. A case associated with a P. chamissonis bite occuring during a summer activity in San Antonio, V Region, is presented. The bite compromised the dorsum of the right hand between the thumb and the index finger and was initially painless. During the following 24 hours equimotic edema developed up to the shoulder and pectoral region, with intense pain, headache, nausea, fever and appearance of a serohematic bulla on the elbow fold. The patient was treated with antihistamins, systemic steroids, analgesia and antibiotics for 7 days. Other cases of snake bites published in Chile are reviewed and treatment and prevention strategies are proposed.Key words: snake bite, snake venom; Philodryas chamissonis; Tachymenis peruviana. Palabras claves: mordedura de culebra; ofidismo; empozoñamiento; Philodryas chamissonis; Tachymenis peruviana. afectados, con una incidencia variable de 45 a 1.000 casos por 100.000 habitantes. La mayoría son producidos por serpientes del género Bothrops (jararaca), Crotalus (serpiente cascabel) y con menor frecuencia Lachesis (sururucu) y Microcurus (coral) 2 . En Chile continental los ofidios están representados por siete formas de la familia Colubridae. Dos tipos de culebras se han relacionado a accidentes por mordeduras en humanos: Philodryas chamissonis (anteriormente Dromicus chamissonis), llamada culebra de cola larga y Tachymenis peruviana, o culebra de cola corta. Philodryas chamissonis se encuentra distribuida entre la IIIª y Xª Región (Atacama a Los Lagos) y T. peruviana desde la IVª a la IXª Región. Ambas tienen dentición opistoglifa 3 . Las culebras descritas en nuestro país atacan al hombre sólo en defensa propia. Los accidentes por mordeduras se presentan esporádicamente y se ubican en las extremidades y en los dedos de personas que toman estas culebras 4,5 . Philodryas chamissonis es el ofidio de mayor tamaño en nuestro país, puede tener hasta 2 m de longitud. Se caracteriza por presentar en el dorso una línea longitudinal central y continua de color pardo oscuro casi negra, con franjas amarillas laterales, que permite su identificación morfológica. Destacan sus ojos con dos escamas post oculares y las pupilas circulares.Tachymenis peruviana mide de 40 a 60 cm, posee Introducción las serpientes se les reconoce por la ubicación de los dientes inoculadores y sus características morfológicas. Las serpientes consideradas venenosas son aquellas con dentición proteroglifa (del griego protero= anterior y glifis= muesca), que tienen los colmillos ubicados anteriormente, de tal manera que al clavar la presa, permite que el veneno fluya libremente 1 y las solenoglifa (del griego solenius= conductor y glifis= ranura), que es la forma más perfeccionada de evolución del aparato ponzoñoso. A este último grupo pertenecen la serpiente cascabel y víbo-ras entre otras.Las aglifas (del griego a= sin...

Philodryas (Serpentes: Dipsadidae) Envenomation, a Neglected Issue in Chile

“…All snakebites produced by P. chamissonis were due to the fact of improper animal manipulation or casual snakebites in the upper extremities, especially the fingers. The age of the victims ranged from 11 to 25 years; six cases involved men and one case a woman [31,[36][37][38]. All accidents occurred during the summer season, in December and January.…”

“…From all they, P. chamissonis snakebite reports with clinical importance have been published describing the evolution of symptoms. At the time of the bite, all patients did not report pain [31,38]. Local lesions were made up of small punctiform wounds produced by snake teeth [42] which, in some cases, remained in the bite site [38].…”

“…The reported cases recorded inflammation at the inoculation site in the first 10 to 30 min, accompanied by an intense throbbing pain and heat sensation spreading throughout the affected limb in the following hours [36,38]. Laboratory tests for pediatric and adult patients showed hypoprothrombinemia and prolonged activated partial thromboplastin time (aPTT) with liver, urine, electrocardiogram, plasma electrolyte, and blood glucose tests in normal ranges within the first 24 h after ophidic accident [16,31,36]. The local symptoms produced by cis-Andean Philodryas species, such as P. olfersii, P. patagoniensis, P. viridissima, and P. baroni, are similar to those described for P. chamissonis, i.e., edema, intense pain, bleeding for few minutes, swelling, ecchymosis, and, in some cases, lymphadenopathy; the duration of these effects ranged from 1 to 7 days, with positive clinical results [11,12,14,17,18].…”

“…During this time, edema with a stiff appearance induced by P. chamissonis snakebite extended to the shoulder region and chest area with ecchymosis spots and supra-epitrochlear and axillary adenopathies sensitive to palpation [16,31,36]. Some patients exhibited fever, headache, nausea, and a tendency to hypotension.…”

“…Although evidence concerning snake envenoming caused by Chilean snake species of the genus Philodryas exists from the 1940s, poorly available information on snakebite envenoming situates Chile within countries with insufficient clinical and epidemiological information [30]. Moreover, the apparent low incidence of snakebites and lack of human mortality associated to snake envenoming [31,32] have led to the underestimation of morbidity and non-inclusion in official health programs [33]. Certainly, this knowledge gap highlights the need for identifying the research focus that requires important contributions for new treatments and effective diagnosis as well as molecular and preclinical information.…”