Snakebites can cause local effects (swelling, redness, laceration) and in case of poisonous snakes, local and systemic effects caused by envenomation. More than 50% of bites are “dry” i.e. no envenomation occurs, and most bites are from non-venomous snakes.

In the event that poison is injected, the effect depends on the type of venom, quantity, location of the bite and size and general condition of the victim.


  • Common poisonous snakes in Uganda: puff adder, Gabon viper, black and green mambas, boomslang and several cobras

Clinical features

  • Puncture wounds, pain, swelling, discoloration
If cytotoxic venom
  • Extensive local damage with swelling, pain, regional lymphadenopathy – starting 10-30 minutes after the bite
If neurotoxic venom (e.g. green and black mamba)
  • Weakness and paralysis of skeletal and respiratory muscles (drooping eyelids, difficulty in swallowing, double vision, slurred speech, difficulty in breathing) – starting 15-30 minutes after the bite
  • Excessive sweating and salivation
If hemotoxic venom
  • Bleeding, oozing from the site, bloody blisters
  • Haematuria, haematemesis – even after some days


  • Whole blood clotting test at arrival and every 4-6 hours for the first day: put 2-5 ml of blood in a dry tube and observe after 30 minutes: if incomplete or no clotting, it indicates coagulation abnormalities


  • Wash site with a lot of clean water
  • Wipe away excess venom
  • Assess skin for fang penetration
  • If there is a wound, clean it with a lot of clean water
If signs of fang penetration
  • Apply firm crepe bandage to entire limb to ensure constant pressure (except if cytotoxic)
  • Immobilise limb with a splint
  • Analgesic e.g. paracetamol (avoid aspirin)
  • If no signs and symptoms for 6-8 hours: most likely bite without envenomation
  • Observation for 12-24 hours recommended
  • Tetanus toxoid (TT) IM 0.5 ml if not previously immunised in the last 10 years
If local necrosis develops
  • Remove blisters, clean and dress daily, debride after lesions stabilise (minimum 15 days)
Venom in eyes
  • Irrigate eyes with plenty of water
  • Cover with eye pads
Criteria for referral for administration of antivenom
  • Signs of systemic poisoning (paralysis, respiratory difficulty, bleeding)
  • Spreading local damage:
    • Swelling of hand or foot (site of most bites) within 1 hour of bite
    • Swelling of elbow or knee within 3 hours of bite
    • Swelling of groin or chest at any time
    • Significant swelling of head or neck
  • Antivenom sera polyvalent (E & C Africa)
    • Check package insert for IV dosage details.Ensure the solution is clear and check that patient has no history of allergy
  • Indicated only if wound is infected


  • Do not apply a tourniquet
  • Do not squeeze or incise the wound
  • Do not attempt to suck the venom out