Dangerous bite?—Yes, potentially, but rarely so. We talked to Ilaria Ippoliti, Lecturer in Pharmacology at UniCamillus University
Its name could even deserve sympathy, except for the fact that it spreads terror across Italy and beyond. In the last few weeks, the bite of the brown recluse spider—whose scientific name, Loxosceles rufescens, is more high-sounding—has attracted increasing media attention and great concern in Italy due to a number of serious episodes. Among these, we must mention the death of Giuseppe Russo, a 23-year-old man who died in Apulia due to complications from a brown recluse spider bite, as well as the terrible experience of Martina Berti, a very young woman from the Veneto region who was bitten in the leg and nearly suffered necrosis to the limb.
But is it really that dangerous? Or can it be kept under control? First of all, let’s learn more about the brown recluse spider. This spider belongs to the Sicariidae family and is so called because it has a characteristic spot on its body that is similar to a musical instrument. Its size is very small: 9 mm long, 5 cm with legs. It can be found practically everywhere in Italy and prefers warm and dry climates—it is no coincidence that it is most frequently found in the summer, perhaps nestling between cracks in walls, behind skirting boards or between the folds of some comfortable upholstery fabric.
A brown recluse spider bite is not usually lethal and often shows up as a moderate skin lesion. The most common symptoms include soreness, itching, swelling and redness, which may disappear quickly. However, in some cases, especially in vulnerable people or those who have a history of disease, the bite can cause more serious complications such as tissue necrosis and infection, which can sometimes result in death.
Despite the alarm caused by possible unfavourable outcomes, the bite can be treated through disinfection and monitoring, without the need for hospitalisation. However, if neglected, things could progress more problematically.
In order to find out more, we talked to Ilaria Ippoliti, Lecturer in Pharmacology at UniCamillus University.
How do you know if you have been bitten by a brown recluse spider or another insect?
‘Brown recluse spiders (Sicariidae family, Loxosceles genus) are arachnids with a violin-shaped thorax. They are sedentary insects typical of the Mediterranean area, but they can be found in hidden places where humans are not very present. They are not aggressive insects and tend to flee rather than attack humans, so that there are few confirmed cases of bites, which are generally painless. However, sometimes, even if accidentally, they can bite and cause haemorrhagic and necrotic skin lesions. Unfortunately, the bite and its characteristics do not differ from those caused by other biological toxins such as, for example, those released by other insects. Therefore, the only way to say whether you have been bitten by this spider or not is to pick it up and take it to specialised centres so that it can be identified.’
What are the characteristic symptoms?
‘The signs and symptoms caused by the bite of a brown recluse spider are variable and are collectively referred to as ‘loxoscelism’, a syndrome affecting the skin and systemically induced by the spider’s venom. The skin area affected by the bite may not show any changes. In clinically relevant cases, however, a reddened lesion, itching, burning and tingling may appear in the hours following the bite. In more severe cases these lesions may ulcerate and the risk of infection increases.
In most cases, brown recluse spider bites require only general supportive care, but when the lesions are severe and tend towards necrosis, healing time may be prolonged and scarring may remain. In rare cases of systemic loxoscelism, the first symptoms (fever, nausea, muscle pain and/or joint pain, headache) may appear within minutes of the bite and, subsequently, severe intravascular, nephrological and/or multi-organ damage may occur, which need to be treated more specifically in the hospital. These more severe reactions are more likely to occur in individuals who are prone to allergic reactions. It is therefore important that loxoscelism is diagnosed by medical staff, avoiding harmful outcomes.’
How can you prevent the bite?
‘The brown recluse spider has always been present in Italy and there is no data to justify an increase in the level of attention concerning the danger of human exposure to the spider’s bite. The spider is mainly found in places with little light, dry and scarcely visited by humans both outdoors and indoors (under stones and in cavities, even inside buildings). So it is always preferable to avoid such places or, if necessary, to wear suitable protection such as long clothing or gloves. Accidental contact between humans and the brown recluse spider is possible but the bite is not very frequent.’
Once you are sure that you have been bitten by a brown recluse spider, what should you do? Is it dangerous to wait?
‘If you are sure that you have been bitten by a brown recluse spider, it is advisable to:
- avoid manipulating or incising the area where you have been bitten.
- wash the area with soap and water, without using aggressive disinfectants.
- pay attention to the appearance of symptoms of any kind, taking care to monitor the evolution of the skin lesion.
- contact the emergency number and Poison Control Centre, especially if local or systemic symptoms appear in the following hours and get worse.
Only with expert advice will it be possible to carry out an effective and targeted treatment. No home remedy should be used to avoid worsening the symptoms and clinical signs.’
When should you be worried?
‘If you suspect that you have been bitten by a brown recluse spider, it is always advisable to act with watchful waiting. In such cases, it is always a good idea to seek medical advice and, if a reddened lesion appears accompanied by itching, burning and tingling, which, over the next few hours becomes ulcerated, it is advisable to contact Poison Control Centres or hospitals to receive appropriate treatment.’
Bibliography
1. A. Tammaro; G.A.R. Adebanjo; C. Chello; F.R. Parisella; P. Reen ;H.P. Erasmus; A. Capalbo;G. De Marco (2021). Violin spider: two car mechanic brothers bitten in Rome. Journal of the European Academy of Dermatology and Venereology. doi:10.1111/jdv.17149
2. Nentwig W, Pantini P, Vetter RS. Distribution and medical aspects of Loxosceles rufescens, one of the most invasive spiders of the world (Araneae: Sicariidae). Toxicon. 2017 Jun 15;132:19-28. doi: 10.1016/j.toxicon.2017.04.007. Epub 2017 Apr 10. PMID: 28408204.
3. https://www.aslroma3.it/informativa-sul-ragno-violino-notizie-utili-da-sapere/
4. https://www.policlinicogemelli.it/news-eventi/morso-da-ragno-violino-le-corrette- informazioni-sui-rischi-per-luomo/
5. Spiders of the genus Loxosceles (Araneae, Sicariidae): A review of biological, medical and psychological aspects regarding envenomations. January 2009, Journal of Arachnology 36(Apr 2008):150-163. 36(Apr 2008):150-163. DOI:10.1636/RSt08-06.1