Masters Degrees (Clinical Pharmacology)

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Browsing Masters Degrees (Clinical Pharmacology) by Subject "Antineoplastic drugs"

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    Venomous spider bites in south africa: epidemiology and clinical features
    (Stellenbosch : Stellenbosch University, 2019-04) Du Plessis, Catharina Elizabeth; Reuter, Helmuth; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medicine: Clinical Pharmacology.
    Introduction: Worldwide the number of spider bite calls to poison centres comprises less than 2.5% of calls. Only a small proportion of spiders cause serious envenomation in humans. The known medically important spiders of South Africa include the Latrodectus (button), Cheiracanthium (sac) and Loxosceles (violin) species. The button spiders can cause neurotoxicity called latrodectism while violin and sac spider bites can cause necrotic skin lesions. The clinical syndrome of latrodectism is well defined and an effective antivenom is available. The diagnosis of necrotic arachnidism on the other hand is more difficult, especially if the spider bite is not painful. The necrotic skin lesions are not specific and have a wide differential diagnosis. Aim: The main aim of the study was to perform a retrospective assessment of poison centre data regarding spider bites from January 2005 to December 2017 and to develop an algorithm for the diagnosis of spider bites. Results: From a total of 83 974 calls, 1917 (2.3%) were related to suspected spider bites. The majority of these calls were from the Western Cape Province. The majority of bites occurred during the warmer months of the year, peaking in January and February. Adults were involved more frequently than children, 1497 versus 420, respectively. In 138 (48.6%) of the 284 reported button spider bites, the spider was positively identified. Of these, 80 (28.1%) patients were treated with antivenom. The most common clinical features were generalised pain (n = 89, 31.3%), muscle pain and cramps (n = 88, 31.0%) and sweating (n = 58, 20.4%). In the cytotoxic spider group only 5 spiders were positively identified. In the majority of calls the spider was not seen or could not be identified (n = 1301, 68%). Discussion: The number of spider bite calls to poison centres are low when compared to the total number of calls received. Bites usually involved adults and occurred mostly during the warmer months of the year. There has not been a single death associated with spider bites. In terms of a Poison Information Centre helpline data collection suggested categories for the diagnosis of spider bites include definite, probable and unlikely. Based on the clinical presentation it is possible to diagnose neurotoxic spider bites caused by button spiders with confidence and advise the use of the antivenom when indicated. A positive response to the antivenom supports the presumed diagnosis. It is more difficult to diagnose cytotoxic spider bites and the majority reported skin lesions are unlikely to be caused by spiders. We have developed a diagnostic algorithm that incorporates the most important clinical features and the distribution of spiders to assist with the diagnosis. Conclusion: In the majority of spider bites it is unlikely that serious effects will develop, however the early identification of a spider as well as the recognition of a clinical syndrome associated with certain spider bites, would assure safe and effective treatment. The helpline data is insufficient to fully describe necrotic arachnidism and further prospective studies are warranted.