Signs & symptoms

Local injury and local effects

The venom of Trachinus sp. contains venom components that can induce severe pain and cause local tissue reactions.

Puncture wounds, pain, oedema (Cain 1983).

Systemic effects

Rare. Moreover it is doubtful if these are truly primary effects of the venom and not secondary, for instance in the context of the severe pain.

Morbidity

In more recent times no fatalities have been reported. The fatal cases of envenoming mentioned in the literature could have been the result of infectious complications.

Case fatality rate

Wound infections, necroses.

First aid and treatment

Immersion of the affected extremity in water as hot as can be tolerated, especially if it is not possible to get immediate medical assistance (water temperature approx. 45°C; temperature should be checked by a companion or with a healthy extremity in order to avoid burns; duration of treatment if necessary >30 min). The venom of Trachinus sp., which, in addition to the physical injury, is responsible for pain and tissue destruction, is believed to be heat-labile. It is assumed that the hot water treatment may have an inactivating effect on the venom. However, this method is controversial, due to the risk of additional tissue damage. Its efficacy has not yet been documented in a controlled study.

Symptomatic treatment

Pain: injection of a local anaesthetic without the addition of a vasoconstrictor (lignocaine 1%) directly into and around the wound (Fenner et al. 1989). Nerve block anaesthesia with lignocaine 1% or preferably bupivacaine because it has a longer duration of action (analogous to Fenner et al. 1989b, Dormon 1985).

Injury: wound cleaning and disinfection.

Tetanus prophylaxis. Antibiotic treatment if there is a clinically evident wound infection. Regular wound inspection and change of dressing until the wound has healed fully.