Scorpion sting

Symptoms

• Immediate, burning or stabbing pain
• Tingling, numbness, paresthesia, or hypersensitivity around the sting
• Mild erythema or swelling, often much less impressive than the pain
• Occasionally local sweating or itching

• Restlessness, anxiety, agitation
• Sweating, salivation, lacrimation, rhinorrhea
• Nausea, vomiting, abdominal pain, diarrhea
• Blurred vision, abnormal eye movements, slurred speech, difficulty swallowing or handling secretions
• Muscle twitching, fasciculations, jerking, tremor, or abnormal limb movements
• Palpitations, chest pain, breathlessness

Signs of systemic envenoming

Evaluation

1. Immediate assessment

• Airway: secretions, dysphagia, gag/cough, aspiration risk
• Breathing: respiratory rate, work of breathing, oxygen saturation, chest crepitations
• Circulation: pulse, blood pressure, capillary refill, extremity temperature, urine output
• Disability: mental status, agitation, neuromuscular activity, cranial nerve signs
• Exposure: inspect sting site, search for edema/necrosis, and check for evidence of allergy or infection.

• Time and site of sting
• Region of exposure and, if safe, a photo or description of the scorpion
• Progression of symptoms and any prehospital treatment
• Age and weight, especially in children
• Cardiac, respiratory, renal disease, pregnancy, and drug allergies.

2. Severity classification

• Mild: Local pain/paresthesia only, stable vital signs.
• Moderate: Autonomic or neuromuscular findings, such as vomiting, sweating, salivation, agitation, tachycardia, hypertension, or muscle twitching.
• Severe: Airway compromise, respiratory distress, pulmonary edema, shock, altered consciousness, dangerous arrhythmia, severe neuromuscular dysfunction, or myocardial dysfunction.

3. Investigations

• Continuous cardiac monitoring, repeated BP, pulse oximetry, temperature, and urine output
• ECG
• Blood glucose, CBC, electrolytes, urea/creatinine, liver tests
• ABG/VBG and lactate if respiratory distress, shock, or severe illness
• Troponin and CK/CK-MB if cardiac injury is suspected
• Chest radiograph for pulmonary edema
• Echocardiography if signs of heart failure, shock, persistent hypotension, abnormal ECG/troponin, or pulmonary edema
• Urinalysis for hemoglobin/myoglobin and renal involvement
• Serum lipase/amylase if abdominal pain or vomiting suggests pancreatitis.

Management

First aid

• Reassure the patient and keep them still.
• Wash the sting site with soap and water.
• Apply a cold pack wrapped in cloth intermittently for pain.
• Remove rings, bangles, or tight items from the affected limb.
• Transport promptly to medical care if the patient is a child, symptoms are more than local, or the species may be dangerous.

Mild sting

• Oral paracetamol or an NSAID if suitable
• Local anesthetic infiltration may be considered for severe local pain
• Cold compresses and elevation
• Update tetanus immunization when indicated
• Short observation, with discharge only if vital signs remain normal and there are no systemic features.

Moderate or severe envenoming

1. Airway and breathing
   • Supplemental oxygen.
   • Suction secretions and protect the airway when bulbar dysfunction is present.
   • Early intubation and mechanical ventilation for respiratory failure, inability to protect the airway, or severe pulmonary edema.
2. Monitoring and support
   • Cardiac monitor, frequent reassessment, strict input/output.
   • Establish IV access.
   • Use IV fluids carefully. Pulmonary edema may be cardiogenic, so indiscriminate fluid boluses can worsen it.
3. Agitation and neuromuscular excitation
   • Benzodiazepines may be used with close respiratory monitoring.
   • Opioids or sedatives can depress respiration, especially in a patient with bulbar weakness or excessive secretions.
4. Cardiovascular complications
   • Treat pulmonary edema, cardiogenic shock, hypertension, or arrhythmias in a monitored critical-care setting.
   • For species causing catecholamine-mediated cardiovascular toxicity, specialist protocols may use vasodilators such as prazosin or nitroglycerin and inotropic support such as dobutamine for cardiogenic shock.
   • Management should be guided by BP, perfusion, ECG, echocardiography, and evidence of pulmonary edema. Tintinalli’s Emergency Medicine, p. 1397.
5. Antivenom
   • Give species-appropriate, locally available scorpion antivenom for clinically significant systemic envenoming, especially progressive neurotoxicity, cranial-nerve/bulbar dysfunction, severe autonomic features, respiratory compromise, or cardiovascular toxicity.
   • Antivenom is not usually indicated for pain alone.
   • It must be administered where anaphylaxis can be recognized and treated, because immediate allergic reactions and delayed serum sickness can occur.
   • Product selection and dose are regional and species-specific. Do not substitute snake antivenom.
6. Prazosin in India
   • In Indian red scorpion envenoming with autonomic/cardiovascular features, prazosin is widely used as an alpha-1 blocker under local pediatric/adult protocols and monitoring. Published Indian practice commonly uses weight-based repeat dosing, but the exact regimen should follow the local emergency or poison-center guideline rather than self-treatment. An Indian pediatric observational study describes 30 micrograms/kg per dose with repeated dosing and cardiac support as needed, but this is not a universal protocol. Indian pediatric study

When it is an emergency

• Any sting in an infant or young child
• Vomiting, sweating, drooling, agitation, abnormal movements, weakness, blurred vision, or trouble swallowing
• Fast or irregular heartbeat, chest pain, fainting, cold extremities
• Breathlessness, wheeze, low oxygen level, or frothy sputum
• Reduced urine output, dark urine, or severe abdominal pain
• Facial/tongue swelling, generalized hives, or anaphylaxis.