Page 13 of 20

IM21.9 | Bee Sting and Other Envenomation — SDL Guide

Learning Objectives

• Distinguish anaphylaxis from direct toxic envenomation in bee and wasp sting, and describe the specific management for each
• Describe the first-aid management of jellyfish envenomation, including the role of vinegar and what must be avoided
• Describe the clinical presentation of centipede and black widow spider envenomation and their management principles
• Apply adrenaline 0.5 mg IM as the correct first-line treatment for anaphylaxis from any envenomation source
• Recognise the renal risk from massive bee/wasp envenomation and describe the supportive management targeting pigment nephropathy

INSTRUCTIONS

Bee stings, jellyfish, and arthropod envenomation form the broad and diverse end of the envenomation spectrum. This module equips you to recognise the two critical distinctions — anaphylaxis versus toxic envenomation, and the specific first-aid steps for each arthropod — so that you can act correctly in the first minutes of any envenomation emergency.

References

• Harrison's Principles of Internal Medicine, 21st ed. — Arthropod Envenomation; Anaphylaxis (textbook)
• API Textbook of Medicine, 10th ed. — Chapter on Envenomation (textbook)
• World Allergy Organization (WAO) Anaphylaxis Guidelines, 2020 Update (guideline)

---

Version 2.0 | NMC CBUC 2024

Bee and Wasp Sting: Clinical Spectrum and Management

Bee and wasp stings produce two entirely distinct clinical syndromes depending on whether the patient is sensitised (prior exposure has generated IgE antibodies) and whether the sting is single or massive. Recognising which syndrome is present within the first few minutes of evaluation determines whether the treatment is adrenaline (anaphylaxis) or supportive ICU care (toxic massive envenomation). Conflating these two syndromes is a dangerous error: giving antihistamines as first-line treatment for anaphylaxis is inadequate, while treating a massively stung patient with only adrenaline misses the unfolding organ-system toxicity.

Syndrome 1 — Anaphylaxis from a single (or few) sting(s) in a sensitised individual:
Bee venom contains phospholipase A2 and melittin as major allergens. In a sensitised person (previous bee sting with sensitisation), re-exposure triggers a type I IgE-mediated anaphylactic reaction. The clinical presentation is characterised by rapid onset (seconds to minutes) of: generalised urticaria and pruritus, angioedema (face, lips, tongue), bronchospasm (wheeze, breathlessness), stridor (laryngeal oedema), hypotension, tachycardia, and potentially loss of consciousness. Anaphylaxis is defined clinically as a severe, life-threatening systemic hypersensitivity reaction — and bee sting is one of the most common triggers in India. Without immediate treatment, cardiovascular collapse and death can occur within minutes.

Management of bee sting anaphylaxis:
- Adrenaline 0.5 mg IM (1:1000 solution, 0.5 mL) into the anterolateral thigh — the first and only life-saving treatment, given before anything else. This is the same action as for antivenom anaphylaxis. Repeat every 5–15 minutes if response is inadequate.
- Remove the stinger by scraping (not pinching — pinching squeezes residual venom from the venom sac into the wound).
- Lay flat with legs elevated if hypotensive (unless respiratory distress — then semi-recumbent).
- IV access and IV normal saline 500–1000 mL for hypotension.
- IV chlorphenamine 10 mg and IV hydrocortisone 200 mg as adjuncts (onset delayed).
- Salbutamol nebulisation for persistent bronchospasm.
- Monitor for biphasic anaphylaxis (recurrence 1–8 hours later) — observe for minimum 4–6 hours.
- Prescribe an auto-injector adrenaline pen (EpiPen) and allergy referral for long-term management.

Bee Sting Anaphylaxis Management Algorithm

Syndrome 2 — Massive/toxic bee envenomation (>50 stings, typically >100):
When a large number of stings occur simultaneously — as in an attack by an entire hive (50–1000+ stings) — the cumulative venom load produces direct toxicity independent of prior sensitisation. The venom components cause: haemolysis (phospholipase A2 destroys red cell membranes → haemoglobinuria → pigment nephropathy), rhabdomyolysis (melittin-mediated myonecrosis → myoglobinuria), hepatotoxicity, direct nephrotoxicity, and in severe cases a consumption coagulopathy. The clinical presentation is systemic collapse without the urticarial/bronchospasm pattern of anaphylaxis: dark urine, jaundice, diffuse oedema, and acute kidney injury developing over hours to days. There is NO role for adrenaline in purely toxic envenomation — the mechanism is not IgE-mediated.

Management of massive bee envenomation:
- Remove all stingers by scraping.
- Aggressive IV fluid hydration (normal saline 200–300 mL/hour) targeting urine output ≥200 mL/hour — the priority is to flush haemoglobin and myoglobin casts from the renal tubules.
- Monitor urine colour and dipstick (dark urine + blood on dipstick + no red cells on microscopy = pigment nephropathy).
- Serial serum creatinine, CK, LDH, and liver enzymes.
- Manage acute kidney injury with nephrology input; dialysis if renal failure progresses.
- Antihistamines for any urticarial component.
- ICU admission for systemic toxicity with ≥100 stings.

Jellyfish Envenomation

Jellyfish envenomation is encountered in coastal states of India — Kerala, Tamil Nadu, Karnataka, Andhra Pradesh, Odisha, Maharashtra, Gujarat, and West Bengal — and in the Andaman and Nicobar Islands. The envenomation mechanism is unique: jellyfish tentacles carry thousands of microscopic nematocysts — highly pressurised coiled tubules that discharge on contact with skin, injecting venom through the epidermis. The discharge is triggered by touch and is essentially instantaneous; even tentacles separated from the jellyfish remain capable of firing nematocysts for hours. This is why a common mistake — rubbing the affected area with a towel — causes thousands of additional nematocyst discharges and dramatically worsens envenomation.

Clinical presentation: Most jellyfish stings in India cause local envenomation only: immediate intense burning pain, linear or branching erythema following the tentacle contact pattern ('whiplash marks'), oedema, and vesicle formation over the subsequent hours. The pattern of the marks often retains the branching geometry of the tentacle, which is pathognomonic.

Systemic envenomation is uncommon from the jellyfish species commonly encountered in Indian coastal waters but can occur with specific species (Physalia physalis — Portuguese man-o-war is not a true jellyfish but a siphonophore, but causes similar stings; Chironex fleckeri — the Australian box jellyfish — is not found in Indian waters but is taught for completeness). Systemic features, when they occur, include: nausea, vomiting, muscle cramps, arrhythmias, and in severe cases cardiovascular collapse.

Management:
1. Do NOT rub the area — rubbing discharges additional nematocysts.
2. Remove tentacles by flushing with seawater (NOT fresh water — fresh water changes osmolality and triggers nematocyst discharge) and picking off remaining tentacles with tweezers or a credit card-edge scraping motion.
3. Deactivate remaining nematocysts: Apply 5% acetic acid (household vinegar) to the affected area for 30 minutes — vinegar acidifies the nematocyst and prevents discharge. This is the standard first aid. Isopropyl alcohol 70% is an alternative.
4. Analgesia: Oral paracetamol or tramadol for pain. Topical lignocaine gel or ice pack for local relief.
5. Antihistamines for urticaria. Systemic features: treat symptomatically. Anaphylaxis (rare): adrenaline IM as above.
6. Tetanus prophylaxis if not up to date.

Jellyfish Sting First Aid Sequence

Centipede, Spider, and Other Arthropod Envenomation

Centipede and spider bites are common in India but rarely cause life-threatening envenomation. The clinical importance of these envenomations lies in correct first aid, accurate diagnosis, and avoiding unnecessary treatment based on overestimated danger. There are no species of truly dangerous spider in India comparable to the black widow or brown recluse of North America, though some local species cause significant local reactions.

Provided image

Centipede envenomation: The Indian giant centipede (Scolopendra species) can reach 20–30 cm in length and delivers venom via a pair of modified front legs (forcipules), not its mouthparts. The bite causes immediate intense burning pain at the bite site, local oedema, erythema, and sometimes lymphangitis. Systemic features are rare but include headache, nausea, and anxiety from autonomic stimulation. Severe reactions with haemolysis and AKI are reported rarely from massive envenomation. Management is supportive: analgesia (paracetamol, tramadol, or local infiltration of lignocaine for severe pain), wound cleaning, tetanus prophylaxis, and observation for 4–6 hours for systemic features. Ice application for 10–15 minutes reduces local pain. No antivenom is available.

Spider envenomation: Most spider bites in India cause only local reactions — pain, erythema, and minor swelling. The black widow spider (Latrodectus species) is present in India and produces the latrodectism syndrome: severe abdominal cramps, diffuse muscle spasm (mimicking acute abdomen), tachycardia, hypertension, and diaphoresis — caused by massive catecholamine and acetylcholine release from spider venom (similar mechanism to scorpion). Management is supportive: opioid analgesia for cramps, benzodiazepines for muscle spasm, antihypertensives if needed. Black widow antivenom is available in some countries but not routinely in India; supportive management is the standard of care. The brown recluse spider (Loxosceles species) is not native to India but causes a necrotic local wound where present globally.

Wasp envenomation: Wasp stings follow the same principle as bee stings — single sting in a sensitised individual → anaphylaxis (treat with adrenaline IM); massive sting attack → direct toxicity with haemolysis and AKI (supportive care, aggressive IV fluids). The distinction between anaphylaxis and toxic envenomation applies to all Hymenoptera (bees, wasps, hornets) stings.