National Poisons Information Service

A service commissioned by Public Health England




Members of the public

seeking specific

information on poisons

should contact:


In England and Wales:

NHS 111 - dial 111


In Scotland:

NHS 24 - dial 111


In N Ireland:

Contact your local GP or

pharmacist during

normal hours; click here

(www.gpoutofhours for GP

services Out-of-Hours.


In Republic of Ireland:

01 809 2166



professionals seeking

poisons information

should consult:

Snake bite

During 2016/17 the NPIS received 113 telephone enquiries concerning snake bites. This represents 0.26% of all enquiries to the service, and is similar to the number of enquiries about snake bites in previous years.


The snake was identified as Vipera berus (European adder) in 51% of enquiries, 38% of enquiries regarded an exotic (non-indigenous) species, while the species was unknown in 11%. All exotic species were reported as being privately owned. The most frequently encountered were hognose snakes (40%), pythons (12%), corn snakes (9%), puff adders (9%), rattlesnakes (9%) and boas (7%). Enquiries related to venomous snakes included puff adders (4), rattlesnakes (3), spitting cobras (2) and mangrove swamp snakes (1).


Seasonal trends showed 86% of enquiries were received between the months April and September with a peak in July (26% of cases) and for Vipera berus reflects times of activity during the warmer months (Figure 1).


Figure 1. Number of snake bite cases reported to NPIS in 2016, by month



The injury site was identified as the upper limb (hand or arm) in 53%, the lower limb (foot, ankle, shin, calf or thigh) in 31% and the head, chest or buttock in 2%. Eye contact with venom from a spitting cobra rather than from a bite was responsible in 2% of cases, while in 11% the site of injury was not recorded.


Eighty-five percent of cases reported features of envenoming including oedema (75%), cardiovascular effects [8% tachycardia; 7% hypotension; 1% hypotension and tachycardia] (16%), gastrointestinal effects (vomiting & diarrhoea) (11%) and anaphylaxis (defined as hypotension with one or more features of orofacial oedema, rash or bronchospasm) (2%).


Twenty-eight cases were assessed by clinicians in consultation with the NPIS as requiring antivenom, and two cases had received antivenom treatment prior to contacting the NPIS. The NPIS has access to National Antivenom Experts / Consultant Toxinologists for the more complex, serious or unusual cases of exposure to exotic animals and seven cases were discussed via this route.


The majority of bites were from Vipera berus but people who keep exotic snakes as pets should be aware of risk of being bitten, and of the need to know the exact species of snake they are keeping so that appropriate treatment may be given in the event of envenomation.

Information from the NPIS Annual Report 2016/17.


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