Bites and Stings

Introduction and Classification of Bites and Stings

Bites and stings are common presentations in Nigerian healthcare settings, ranging from harmless insect encounters to life-threatening venomous snakebites. Categorizing these injuries correctly guides immediate clinical decisions.

• Insect stings: Delivered by bees, wasps, ants, and scorpions, injecting venom that causes local pain or systemic allergic reactions.
• Snakebites: Caused by venomous or non-venomous species, leading to local tissue destruction, neurotoxicity, or coagulopathy.
• Mammal bites: Inflicted by dogs, cats, or humans, carrying a high risk of bacterial contamination and tissue trauma.

Venom Pathophysiology and Toxin Types

Venoms are complex mixtures of proteins, enzymes, and peptides that disrupt normal physiological processes. Understanding these toxins helps nurses anticipate clinical deterioration.

• Cytotoxins: Found in vipers, these enzymes destroy cell membranes, causing local swelling, blistering, and tissue necrosis.
• Neurotoxins: Common in elapids and scorpions, these block nerve impulse transmission, leading to respiratory failure and muscle paralysis.
• Hemotoxins: These interfere with the clotting cascade, resulting in spontaneous bleeding or disseminated intravascular coagulation.

Clinical Assessment and Triage

Rapid evaluation saves lives when dealing with envenomation. Nurses must prioritize the ABCDE framework—Airway, Breathing, Circulation, Disability, and Exposure.

Inspect the wound for fang marks, localized erythema, and edema progression. Always ask the patient about the time of the incident, the animal species if known, and any traditional treatments applied prior to arrival. Document baseline vital signs immediately, repeating them frequently to catch early signs of systemic shock or respiratory compromise.

Management of Insect Stings and Localized Reactions

Most insect stings result in localized pain, redness, and mild swelling. Treatment focuses on symptom relief and preventing secondary infection.

1. Stinger removal: Gently scrape the stinger away using a rigid card or fingernail. Avoid using tweezers, as squeezing can inject more venom from the attached sac.
2. Cleaning: Wash the area thoroughly with soap and clean water.
3. Cold application: Apply a cold pack to reduce pain and vasoconstrict blood vessels, slowing venom absorption.
4. Pharmacology: Administer oral antihistamines and topical calamine lotion or mild corticosteroids to control itching.

Emergency Care for Snakebites

Snakebites demand calm, decisive intervention. First aid myths, such as making cuts or applying tourniquets, worsen patient outcomes and must be discouraged.

• Immobilization: Keep the affected limb still and at or below heart level to minimize lymphatic venom spread.
• Antivenom: Administer polyvalent or monovalent antivenom strictly per hospital protocol once systemic signs appear.
• Supportive care: Monitor for renal failure, maintain intravenous access, and prepare for airway management if neurotoxic paralysis develops.

Recognizing and Treating Anaphylactic Shock

Anaphylaxis is a severe, life-threatening systemic hypersensitivity reaction that can occur within minutes of a bite or sting.

Clinical indicators include urticaria, facial angioedema, wheezing, stridor, tachycardia, and a rapid drop in blood pressure. Immediate intervention requires the prompt administration of adrenaline (epinephrine) intramuscularly into the anterolateral thigh. Nurses must also establish airway patency, administer high-flow oxygen, and set up intravenous fluid resuscitation to combat distributive shock.

Complications, Secondary Infections, and Wound Care

Bites often break the skin barrier, introducing pathogens that cause localized infections, abscesses, or systemic sepsis. Animal bites, especially from dogs and humans, carry high bacterial loads including *Pasteurella* and *Staphylococcus* species.

Management involves thorough wound irrigation with copious amounts of sterile normal saline, surgical debridement of necrotic tissue, and prescribed prophylactic antibiotics. Nurses must monitor for ascending redness, purulent discharge, and fever, while ensuring the patient's tetanus immunization status is updated.

Patient Education and Prevention Strategies

Prevention remains the most effective intervention against bites and stings. Nurses play a crucial role in educating individuals, families, and communities on safety measures.

• Advise wearing protective boots and long trousers when walking through tall grass or farming.
• Recommend clearing brush, firewood, and debris away from residential housing to deter snakes and scorpions.
• Instruct individuals with known insect allergies to carry an epinephrine auto-injector and wear medical alert identification.
• Emphasize avoiding provocation of stray animals or wild snakes.