Last September, a 60-year-old woman from s’Arenal d’en Castell, Menorca, felt a sharp sting on her arm while putting on a jumper. At first, she did not think much of it, but the affected area became swollen and she experienced severe pain for two days, to the point that she could not sleep. She went to a pharmacy and was advised to apply an antihistamine and antibiotic ointment, and was told that they had already treated similar cases caused by spider bites. The woman went to the health centre, pointing out that she had possibly been bitten by a Loxosceles rufescens, better known as the Mediterranean violin spider or corner spider. ‘That’s impossible, there aren’t any here,’ the doctor replied, mistakenly.
This case, described by spider biologist Guillem Pons, is one of many he has compiled in an informative article in which he warns of the lack of training among many doctors who are unaware that this species is very common in the Balearics and that after being bitten, quick action is required to prevent the victim’s condition from worsening.
One of the most serious incidents was documented in Ibiza in 2024, when a 32-year-old woman almost lost a leg. The venom caused tissue necrosis, which is the premature and irreversible death of cells and tissues. Fortunately, she was treated in time and saved her limb after multiple surgeries and skin grafts. “These bites can happen anywhere. In Ibiza, there was a case in a car, while a Catalan tourist walking in flip-flops in Cabrera was stung on the side of his foot. It is a very common species that can be found anywhere, especially in cavities or under rocks; I even have a documented case that occurred in a bathroom at the University of the Balearics,” says the biologist.
The bite causes significant pain, more than that of a wasp, and the skin becomes very hot in the area of the bite. When you touch it, it burns, says Pons, who advises that in such a situation, you should go to the doctor as soon as possible, warning them that it is very likely to have been caused by this spider. ‘These are cases that should be known about. The treatment is simple, but prompt attention is required to avoid complications,’ insists the expert, who encourages the Regional Ministry of Health to promote an information campaign in health centres so that both staff and the public can easily recognise if the bite is from this species of spider.
The author of the article presented in November at the IX Jornades de Medi Ambient de les Illes Balears (9th Balearic Islands Environmental Conference) points out that there should be official statistics to determine the real extent of these cases of loxoscelism, which is the name given to the clinical manifestations produced by severe poisoning caused by the bite of spiders of the genus Loxosceles. Greater collaboration between healthcare personnel and entomologists is key to improving diagnosis, treatment and prevention.
The Mediterranean recluse spider (Loxosceles rufescens) is a species of spider that originated in the Mediterranean region as its name implies, but can now be found in many parts of the world and is listed as one of the most invasive spiders worldwide. Usually dwelling in caves, this species will also inhabit basements and tunnels. The spider hunts at night and eats insects including silverfish and cockroaches, and they usually target smaller species.
Similar to other species in their genus, bites from L. rufescens can cause necrosis and, for some individuals, systemic damage due to the enzyme sphingomyelinase D. Pest control may be undertaken with similar strategies as used for the brown recluse spider.
Most cases are medically insignificant, but in some cases, from 2 to 8 hours after a bite, there may be penetrating pain followed by a burning sensation. Areas adjacent to the bite often become red and painful due to vasospasm and ischemia. A blister may form which often changes to a dark blue color with a sunken center days following the bite. In rare cases, hemolysis, intravascular coagulation, and thrombocytopenia can occur, leading to renal failure.
In 2024, L. rufescens has been blamed for the deaths of two individuals in Italy; one a 52-year-old policeman from Palermo, bitten by L. rufescens, according to a local Sardinian newspaper, and the other a 23-year old male, who died more than a month after being bitten, according to ANSA news agency.