Bites showing puncture marks, blistering, bruising and bleeding.
Taking a history in envenoming
• When was the patient exposed
to a bite/sting?
• Was the organism causing it
seen and what did it look like
• What were the circumstances
(on land, in water etc.)?
• Was there more than one bite/
• What first aid was used, when
and for how long?
• What symptoms has the patient
had (local and systemic)?
• Are there symptoms suggesting
systemic envenoming (paralysis,
myolysis, coagulopathy etc.)?
• Past medical history and
• Past exposure to antivenom/
venom and allergies?
Acute poisoning is common, accounting for about 1% of
hospital admissions in the UK. Common or otherwise
important substances involved are shown in Box . In
developed countries, the most frequent cause is intentional
drug overdose in the context of self-harm and usually
involves prescribed or ‘over-the-counter’ medicines. Accidental
poisoning is also common, especially in children
and the elderly (Box ). Toxicity also may occur as a
result of alcohol or recreational substance use, or following
occupational or environmental exposure. Poisoning is a
major cause of death in young adults, but most deaths
occur before patients reach medical attention, and mortality
is much lower than 1% in those admitted to hospital.
In developing countries, the frequency of self-harm is
more difficult to estimate. Household and agricultural
products, such as pesticides and herbicides, are more
freely available, are common sources of poisoning and
are associated with a much higher case fatality. In China
and South-east Asia, pesticides account for about 300 000
suicides each year.