Toxicology - Phosphorus Poisoning

Toxicological aspects of Phosphorus with emphasis on its forms, uses, poisoning: types, diagnosis, treatment, autopsy features and medico-legal importance.

1. . Phosphorus poisoning Adhavan. M Ⅱ MBBS IGMC&RI Puducherry

2. Forms Uses Poisoning Types Diagnosis Treatment Autopsy features Medico-legal importance

3. Phosphorus Inorganic, non-metallic element 2 varieties - yellow/white & red Yellow phosphorous - yellowish, crystalline solid with garlicky odour ; on exposure to air forms whitish fumes; highly combustible; ignites at 34℃; luminescent & phosphorescent Red phosphorus - reddish, amorphous, odourless , insoluble; Not absorbed in GIT - relatively harmless Derivatives - Phosphoric acid, phosphine, aluminium phosphide, zinc phosphide

4. Uses Matches - Lucifer matches - strike anywhere - 1906 Berne convention - safety matches - Potassium chlorate + antimony sulphide Fireworks - Banned in western countries, not in India Military use - Tracer bullets, incendiary bombs, smoke screens, rescue flares Insecticide & rodenticide - Zinc phosphide - cockroaches, rats - e.g. Ratol Fertilizer Medicinal - In homeopathy

5. Poisoning Fatal dose - 60mg (1mg/kg body weight) Mode of action - protoplasmic poison, hepatotoxin; cause shock, CVS collapse; skin, mucosa irritant; oils enhance absorption Poisoning types Fulminant Acute Chronic

6. Fulminant poisoning Ingestion of massive doses - <2g Peripheral vessel collapse Death in 12 to 24 hours Signs of hepatic, renal damage not seen

7. Acute poisoning Common type Stages Ⅰ Ⅱ & Ⅲ Stage Ⅰ - up to 3 days Local side effects - burning pain, vomiting, diarrhoea, pain abdomen, haematemesis Garlic odour breath Vomitus, stool - luminous; fumes from stools

8. Stage Ⅱ - up to several days after stage-Ⅰ Symptom-free Patient well enough to be discharged Stage Ⅲ Due to systemic effects after absorption GI symptoms reappear, more severe Prominent liver damage manifestations - hepatomegaly, jaundice, pruritus, bleeding, hepatic encephalopathy - drowsiness, confusion, ataxia, flapping tremor, stupor, coma

9. Stage Ⅲ contd. Mousy odour of breath - foetor hepaticus Renal damage- oliguria, haematuria, albuminuria, renal failure ECG changes - tachycardia, ST & T wave changes, QT prolongation, low voltage QRS, arrhythmias Terminal convulsions before death Dermal contact - painful corrosion with yellow, necrotic, severely painful 2nd, 3rd degree chemical burns with garlic odour; absorption from damaged skin - systemic poisoning

10. Chronic poisoning Long term occupational exposure to phosphorus pentoxide fumes Phossy jaw, Glass jaw, Lucifer’s jaw Toothache - recurrence - extraction - bone exposed - necrosis, sequestration, osteomyelitis of lower jaw Red phosphorus - dermatitis

11. Diagnosis Garlicky odour of breath, vomitus Fuming, luminous vomitus & stools Evidence of hepatic, renal failure Hypoprothrombinaemia, thrombocytopenia, haematemesis, haematochezia, haematuria, haemorrhages of skin, mucous membranes Hypokalaemia, hyperchloraemia, hypocalcaemia, hyperphosphataemia, hypophosphataemia

12. Treatment Acute poisoning Gastric lavage with KMnO₄, CuSO₄ - risk of combustion Do not administer milk, fatty foods IV fluids Isotonic saline, sodium lactate - treats shock, dehydration, acidosis Glucose - hypoglycaemia Calcium gluconate - hypocalcaemia

13. Whole blood, FFP - agglutination defects Steroids - shock Anticonvulsants - seizures N-acetyl cysteine - prevents progression of liver damage Chronic poisoning Remove patient from source of exposure Dental treatment, follow up

14. Dermal burns Flush with water; clean with soap & water; remove loose, non-viable tissue; give IV analgesics Should not debride closed blisters Prophylactic topical antibiotics - silver sulfadiazine, bacitracin Analgesics - paracetamol, codeine for pain relief

15. Embedded phosphorus removal Visualise by UV lamp Remove with metal forceps Remaining particles - discontinue moist dressing - smoke from crystals - remove manually Deep, extensive injury - consult burns specialist

16. Autopsy findings External Emaciation, purpuric rashes, jaundice, garlicky smell Mucous membrane of mouth is corroded Dark brown coloured hypostasis

17. Internal Multiple haemorrhages in muscles, mucosa, serosa GIT, RS, liver, kidney, heart, peritoneum, lungs, brain Stomach and intestines - mucous membranes: yellowish or greyish-white, softened, thickened, inflamed, corroded in patches; stomach contents - luminous, garlicky smell Liver - swollen, yellow, soft, fatty, friable Kidneys - enlarged, greasy, yellow Heart - flabby, pale, shows fatty degeneration Lungs - fat emboli in pulmonary arterioles, capillaries

18. Medico-legal importance Accidental poisoning - ingestion of cockroach, rat poisons, fireworks by children; contaminated food Suicidal poisoning - Rat pastes like Ratol; formerly in western countries - match heads+brandy+sugar Homicidal poisoning - formerly used - mixed in soups, jams, rum - smell of garlic - unsuspected Arson - covered with dung or wet cloth & thrown on huts Abortifacient - oral, vaginal

19. References Pillay VV. Inorganic non-metallic poisons. In: Comprehensive medical toxicology. 2nd edition. Hyderabad: Paras medical publisher; 2008. p 95-99. Biswas G. Non-metallic and mechanical irritants. In: Review of forensic medicine and toxicology. Third edition. New Delhi: Jaypee brothers medical publishers(P)Ltd; 2015. p 514-516.

20. Thank you