Poisoning: Poisoning remains a critical concern in both emergency medicine and forensic practice. Understanding the types, routes, effects, and medico-legal implications of poisoning is essential, especially in developing countries where poisoning incidents are more prevalent. This guide delves into the types of poisoning, including examples, their diagnosis, emergency treatment, and the legal responsibilities involved.
What is poison?
A poison is any substance—solid, liquid, or gas—that can cause illness, injury, or death when introduced into a living body. Its harmful effects may be local, systemic, or both.
Understanding Toxicology and Forensic Toxicology
Forensic toxicology focuses on the medical and legal aspects of poison, dealing with both living and deceased individuals.
Common Poisons in Developing Countries
According to the WHO, nearly 3 million cases of acute poisoning occur annually, with 90% of deaths happening in developing nations. Factors influencing poisoning trends include:
Poor storage practices
Easy access to agricultural chemicals
Injudicious drug use
Socioeconomic and cultural factors
EPIDEMIOLOGY OF POISON
Types of Poisoning with Examples
1. Based on Cause (Medicolegal Classification):
- Homicidal: Arsenic, aconite, thallium
- Suicidal: Organophosphates (OPC), paracetamol, opium
- Accidental: Kerosene, household cleaners, cosmetics
- Abortifacients: Ergot, oleander, croton seeds
- Aphrodisiacs: Cocaine, cannabis, sildenafil
- Infanticidal: Madar, yellow oleander, common salt
- Rare agents: Bacterial toxins, insulin, corticosteroids
2. Based on Symptoms (Symptomatic Classification):
- Corrosive Poisons:
- Acids: Sulphuric, nitric, hydrochloric
- Alkalis: Sodium hydroxide, potassium carbonate
- Irritant Poisons:
- Inorganic: Arsenic, phosphorus
- Organic: Oleander, castor, calotropis
- Animal-based: Snake venom, wasps, spiders
- Systemic Poisons:
- Cerebral: Alcohol, opioids, amphetamines
- Cardiac: Aconite, cyanide
- Spinal and Peripheral: Nux vomica, curare
Diagnosis of Poisoning in Forensic Medicine
Suspect poisoning when:
- Symptoms appear suddenly and are similar in multiple individuals
- The patient has unusual breath odor or unusual skin color
- Toxins are found in vomit, clothing, or nearby food
🧪 Confirmatory Tests Include:
- Stomach wash analysis
- Vomitus, blood, urine, and stool testing
- Chemical analysis, like TLC, GC-MS, and UV spectrometry
Common Signs and Symptoms of Poisoning
- Nausea, vomiting, diarrhea
- Seizures, delirium, or coma
- Jaundice, liver failure
- Salivation, frothing at the mouth
- Cyanosis, paralysis, or organ failure
Symptomatic Classification
Postmortem Signs of Poisoning
🔹 External Findings:
- Discoloration (e.g., nitric acid turns skin brown, carbolic acid causes grayish-white burns)
- Odor (e.g., garlic in arsenic, fishy in zinc phosphide)
- Signs of struggle or trauma
🔹 Internal Findings:
- Corroded mucosa, gastric ulceration
- Liver, lung, and kidney congestion
- Petechial bleeding, tissue softening
- Toxic smell in body cavities
Medicolegal Duties of a Medical Practitioner in Poisoning Cases
- Provide resuscitation and immediate treatment
- Collect samples for toxicological testing
- Report to police if it’s a homicide case
- In suicidal cases, private practitioners aren’t legally bound to report (unless required by law)
- In death cases, no death certificate should be issued—the report must go to the police
- Record a dying declaration if the patient is critical
Treatment Steps for Poisoning Emergencies
🔹 Resuscitation (ABCD)
- Airway: Clear obstruction, intubation
- Breathing: Provide oxygen or artificial respiration
- Circulation: IV fluids, monitor heart rate
🔹 Removal of Unabsorbed Poison
- Skin: Wash with water and neutralizers
- Inhaled: Move to fresh air, give oxygen
- Ingested: Gastric lavage, activated charcoal
🔹 Administration of Antidotes
- Physical (e.g., charcoal)
- Chemical (e.g., potassium permanganate)
- Pharmacological (e.g., atropine for OPC)
🔹 Enhance Poison Elimination
- Diuretics, dialysis, purging
- Whole bowel irrigation
- Hemoperfusion with charcoal
Ideal Homicidal Poison Characteristics
- Cheap, easily available
- Tasteless, odorless, colorless
- Mimics natural illness
- No antidote or postmortem changes
- Difficult to detect in toxicology reports
Toxicity Measurement and Lethal Doses
| Toxicity Level | Dose (mg/kg) |
|---|---|
| Super toxic | < 5 |
| Extremely toxic | 50–500 |
| Very toxic | 50–500 |
| Moderately toxic | 5–15 gm/kg |
| Slightly toxic | 5–15 gm/kg |
| Practically non-toxic | > 15 gm/kg |
Causes of Accidental Poisoning
- Children ingesting medicines or chemicals
- Pesticides in agricultural communities
- Poor water quality (lead, mercury)
- Adulterated food or expired drugs
- Industrial exposure (CO, ammonia, asbestos)
Prevention of Accidental Poisoning
- Store drugs separately, away from food
- Lock chemicals and medicines
- Label all containers clearly
- Dispose of expired drugs responsibly
- Educate children about food safety
- Ensure good ventilation in kitchens
- Use protective gear in industries
🔚 Final Thoughts
Understanding the types of poisoning with examples is vital not just for physicians and forensic experts but also for the general public. Whether it’s recognizing early signs, knowing what makes a poison homicidal, or carrying out life-saving treatment, awareness can prevent thousands of unnecessary deaths each year.
The following groups of signs and symptoms are suggestive of poisoning:
If it occurs, the sudden onset of
- GI upset—nausea, vomiting, diarrhea
- Coma with the change of pupil
- Convulsion
- Delirium
- Jaundice with hepatic coma or precoma
- Huge salivation
- Frothy discharge per mouth
- Paralysis, particularly LMN type
- Oliguria with proteinuria or hematuria
- Persistent cyanosis
COMMON S/S OF POISONING
- GI upset—nausea, vomiting, diarrhea, abdominal pain
- Coma with the change of pupil
- Convulsion
- Delirium
- Jaundice with hepatic coma or precoma
- Huge salivation, sweating
- Frothy discharge per mouth
- Paralysis, particularly LMN type
- Oliguria with proteinuria or hematuria
- Persistent cyanosis
Symptomatic treatment
Follow up
Rehabilitation
