Types of thermal injuries Definition Old classification Recent classification Dry or simple burn. degree burn AFirst thermal injury is a tissue injurydegree resulting Epidermal 1st & 2nd degree Scald or moist burn. Secondthe degree burn from application of heat in any form to By the external or surface of the burn body. Third degree burn Chemical or internal corrosive burn. Dermo - epidermal Fourth degree burn 3rd & 4th degree Electric burn. Lecturer of Forensic Medicine & Clinical Toxicology Fifth degree burn Deep burn Radiation burn. 5th & 6th degree Sixth degree burn Dry burn Any degree Degree Air passage Contains soot Hair Blood Skin Cause Singed Thick, viscid & contains COHb Dry & charred Flame or heated body Thick with Scar disfigurement Burnt Clothes From below Site & spread upward Charring Vesicles Present At circumference of burnt area Scald 1st, 2nd & No soot 3rd Wet Sodden & bleached Steam or hot Less liquid disfigurement Wet From above downward Absent Over burnt area Corrosive 1st, 3rd, 4th No soot Eaten Stained & corroded Corrosive acid or Much alkali disfigurement Eaten At & below site of contact With mineral Rarely found acid Factors affecting degree of burn A) Extent of burnt area: D) Age is determined by rule of nine of Wallace. B) Depth of burn: E) Sex The 3rd degree burn is the most serious one. F)Site General C) of burn.health. Neck, abdominal wall or genitalia are more dangerous than those of the extremities. Causes of death from burn III) Deathdeath within 2-7 days: I) Rapid Immediate causes "within 6 hours“ II) "within 6-48 hours”: IV) after one week: - Supra-renal haemorrhage. Secondary oligaemic shock. Neurogenic shock. - Rupture of an acute duodenal ulcer (at 12th day) (curling'saccidental ulcer) (stress ulcer): may be due Associated serious injuries to vital - to Bronchopneumonia. hypovolaemia causing devitalization of organs. Secondary toxaemic shock. mucous membrane in addition to the absorbed toxins which excreted by the liver into - burn Inflammation ofare serous membranes. Asphyxia (suffocation). the duodenum. Acute oedema of glottis (in the neck). Traumatic asphyxia. - Septicemia. - Liver, kidney or heart damage: cell degeneration and necrosis of these organs due Tetanus, gangrene and erysipelas.: Pulmonary fat embolism (burn in a fatty area(. to the effect of burn toxins metabolism. Burn vitality Age of Burn Erythema Appears Antemortem immediately burn 36 hs Appears Line of hyperemia Present Vesicles 1w 2-3hs Vesicles Presence of COHb Sepsis Vital reaction Superficial slough Cause of death Deep slough Soot in URT Scar Postmortem burn Red 48 hs Absent 2 ws Albuminous fluid absent poor in rich in chloride albumin and chloride Present Absent 2–3 36 hs Infl., pus 1 healing Nothing But burn days w Nil Other causes 3 ws Present 2m Coppery Absent 6m Postmortem Picture of Burn Complications of Burn --Particles soot are present the air The bodyofshows evidence ofin antemortem passage. burns of various degrees. The body presents a peculiar attitude;hge -- Subcutaneous or subserous peticheal attitude of defence, boxing or "Pugilistic may be present . attitude". Sepsis Deformities - Haemoconcentration of blood due to loss Keloid formation - Crimson red cherry colour red of hypostasis. of plasma and colour of the skin. Generalized visceral congestion Hge --Skull may show thermal fracture and "fissure in the internal organs. fracture“. - Points of differentiation () thermal & traumatic fracture Thermal Fracture The fracturesigns is notofdisplaced Postmortem burn The brain is shrunken Extradural haematoma doesn’t fill the space Traumatic Fracture The fracture Other postmortem signsisofdisplaced death The brain is edematous & associated with contused wound in scalp Extradural haematoma fill the space Factors influencing the effect of electric current Electric burn Physical Voltage Physiological Resistance of body tissue Humidity Nature of current Pathway of current Anticipation of shock Duration of contact General health Causes of Death Ventricular fibrillation Central Respiratory failure Peripheral Cardiac arrest Cerebral anoxia Electric burn Hyperthermic effect Marks P.M. PictureCurrent of Electric Burn NMicroscopic / E appearance appearance - It is of the same size and shape as the - Compression of the stratum corni which Rapid onset of rigor mortis conductor. stains deeply with superficial carbonization. Marked hypostasis Grayish-white painless areas of aseptic - Separation of the cells in the form of slits necrosis. (electric channels). Presence of current mark - They vary from superficial circumscribed - Elongation of both cells and nuclei. severe burns with full thickness lesions Internaltosigns of asphyxia tissue necrosis. -The electric current is DC not AC. Lightning syndrome Definition Characterized by: -About 20.000 amperes. It is the discharge of the atmosphere Loss of consciousness. potential () clouds, or () clouds and -About 100 - 1000 million volts. st degree burn. Earth. Skin burn (similar to 1 Conductive deafness. - A single flash lasts 1/1000th of a second.