Periumbilical Pain with Radiation to Both Legs Following Tarantula Bite; a Case Report.

Tarantulas have recently become as pets in most parts of the world that increased the probability of encountering emergency physicians with patients hurt with these spiders. Their attacks usually do not cause general manifestation, however there are some case reports in this regard. Here, a 40-year-old man was reported who was referred to the emergency department with severe periumbilical pain that radiated to both legs and diagnosed as a victim of tarantula bite. Such symptoms usually are belonging to other spiders like Black Widow spider, but it seems that tarantula can mimic them in some cases, too.

Introduction:

Tarantula is a large spider which usually be found in tropical and subtropical areas, but recently has become as pets in worldwide (1). Consequently, it is more likely that emergency physicians encounter with patients that hurt with these spiders. They are nonaggressive arthropods that if to be forced to defend themselves, flick their needle-like abdominal hair at the target and may rarely bite (2). Though tarantulas may look scary, most of their species are relatively harmless, just a few cases may be dangerous to humans (1). Their attacks generally do not cause general manifestation, however there are some case reports in this regard (3, 4). Here, an unusual presentation of tarantula bite was reported.

Case Report:

A 40-year-old man referred to the emergency department (ED) with severe colicky periumbilical pain, which was non-positional and radiated to both legs. Pain was started from the last day and progressed until arriving to the ED. The patient did not have recent trauma history, except heavy lifting, and also any positive past medical history. On admission time, tachycardia of 110/minute revealed a sinus tachycardia on 12 lead electrocardiogram (ECG) and hypertension of 220/110 mmHg in the right arm and 190/100 mmHg in the left arm. On physical examination, the patient had erythematous and edematous face. The abdominal examination was soft and did not have tenderness or guarding. Straight leg raising (SLR) test did not aggravate the pain and all other systems were normal too. Blood gas analysis and biochemical profile did not reveal any positive findings. With suspicion of large vessel insult abdominal sonography, chest radiography (CXR) and double contrast enhanced computed tomography (CT) were performed, all reported as normal. After ruling out above-mentioned critical impressions, with attention to the history of heavy lifting, herniated disk was suspected so that magnetic resonance imaging (MRI) was requested in which no abnormalities were found. During all these examinations, despite palliative treatments, the patient had severe pain without improvement. Unfortunately, the patient was discharged against medical advice and admitted again after 24 hours with right leg swelling and erythema. In this time, the patient was exposed and several bite-like sites were surprisingly found on his right leg. Another comprehensive history taking revealed that patient was bitten by tarantula at his home.

Discussion:

Tarantulas usually flick their hair at the target, so the most clinical presentations of biting are local allergic reactions including irritation, pruritus, edema, and erythema. If the flicked hair takes place in eye, can result in redness and keratitis. Their bite usually sense as mild pain similar to a pinprick, but can cause severe pain, muscle spasms, local swelling, and numbness or even arthritis (3, 4). In spite of all above-mentioned, there is no properly documented case of permanent deficit or death following the tarantula bite (5). Such severe symptoms almost always belong to other spiders like Black Widow spider (6). Surprisingly, our case had some of these symptoms in spite of being bitten by tarantula. Therefore, we would consider that tarantula bite can mimic symptoms of Black Widow spider envenomation. Laboratory tests and imaging studies are not helpful for evaluation and management (7). In the case of tarantula bite, washing the site with soap and water and applying a cool compress or even an ice cube can reduce the local symptoms. Treatment in the ED is usually conservative and involves administration of antihistamines, corticosteroids, and analgesics (8). Although no specific treatment exists, it has been suggested that calcium supplements may be beneficial to relieve the muscle spasms (4). There is no report of recurrent or delayed reaction yet, so except for rare cases of anaphylaxis, all patients can be discharged after symptom resolution.