Forensic Medicine and Toxicology: Injury, Identity and Poisons
Core concepts
Forensic medicine tests the interpretation of injury and the medicolegal process. Understand wound types and their distinguishing features: abrasion, contusion, laceration, incised wound, stab wound, and gunshot injury, including entry and exit characteristics. Learn the timing of injuries by their appearance, and the distinction between antemortem and postmortem change. Know the signs of death and the estimation of time since death by body temperature, rigor, livor and putrefaction.
Medicolegal topics include consent, confidentiality, the reporting of notifiable conditions, and the duties of a doctor asked to provide a medico-legal report. Toxicology questions are pattern-based: recognise the toxidrome - cholinergic, anticholinergic, opioid, sympathomimetic - and pair it with the agent and antidote. Know the management principles: airway protection, decontamination where appropriate, antidotes, and enhanced elimination.
Traps
Questions often test whether an injury could have been self-inflicted, or whether a wound pattern is consistent with the stated history. Beware of assuming a poison from a single symptom; toxidromes require a constellation. Distinguish the duty to report from the duty of confidentiality - the exceptions are specific and limited.
Rule of thumb
For any poisoning, treat the patient not the poison: support airway, breathing and circulation first, then give an antidote only where one exists and is indicated.
Worked example
A farmer presents with salivation, lacrimation, urination, diarrhoea, bronchospasm and bradycardia after pesticide exposure. This is a cholinergic toxidrome from organophosphate poisoning; management is decontamination, atropine titrated to secretions, and pralidoxime where indicated.