Principles of management of poisons in contact with skin- Dermal toxic exposure (skin contamination)

Dermal toxic exposure occurs when chemicals, biological toxins, industrial agents, pesticides, or household products come into direct contact with the skin. Severity depends on the chemical involved, concentration, duration of exposure, surface area affected, and patient factors such as age and skin integrity.

These exposures may cause local tissue injury, systemic absorption, or life-threatening toxicity.

Risk factors

Environmental and occupational

• Industrial workers exposed to cleaning agents, petroleum products, cement, and solvents

• Agricultural workers exposed to pesticides and herbicides

• Laboratory personnel

• Mechanics exposed to fuels and organic solvents

Household exposure

• Children exposed to detergents and bleaches

• Cosmetic chemicals (hair relaxers, dyes)

• Battery acid exposure

• Accidental spills during cleaning

Patient-related

• Infants and elderly patients

• Open wounds, burns, or eczema

• Delayed decontamination

Clinical presentation

Mild exposure

• Burning sensation

• Erythema

• Itching

• Dryness

Moderate exposure

• Blistering

• Severe pain

• Edema

• Chemical burns

Severe exposure

• Tissue necrosis (especially alkali injuries)

• Gray or white leathery skin

• Systemic toxicity (organophosphates, phenol, cyanide)

• Shock from extensive burns

Diagnostic criteria

Diagnosis is based on:

• History of chemical exposure

• Skin findings compatible with chemical injury

• Evidence of progressive tissue damage

• Evidence of systemic absorption when applicable

Investigations

• Electrolytes (large burns)

• Renal function tests

• Serum cholinesterase (organophosphate exposure)

• Toxicology screening when agent is unknown

• ECG if cardiotoxic exposure is suspected

Non-pharmacological treatment

Immediate decontamination

• Remove all clothing and personal effects immediately

• Brush off dry powders before washing

• Irrigate exposed skin with copious running water:

  • 5 minutes for non-irritants or mild irritants

  • 15–20 minutes for moderate to severe irritants and chemicals causing systemic toxicity

  • 30 minutes for most corrosives

  • 60 minutes for strong alkalis (e.g. sodium, potassium, or calcium hydroxide)

• Use non-abrasive soap and water for oily substances

• Do not attempt chemical neutralization

• Healthcare workers should wear gloves and apron

• Store contaminated clothing in a sealed transparent plastic bag

Special situations

• Phenol: wash with polyethylene glycol if available, otherwise copious water

• Sodium, potassium, and lithium metals: brush off completely before irrigation

• Pesticide exposure: prolonged washing may be required

Pharmacological treatment

• Analgesics (paracetamol or opioids for severe pain)

• Tetanus prophylaxis

• Topical antibiotics for secondary infection

• Steroids only under specialist supervision

• Specific antidotes when indicated (e.g. atropine and pralidoxime for organophosphate poisoning)

Referral

Urgent referral is required for:

• Deep dermal burns

• Tissue necrosis

• Compartment syndrome

• Extensive body surface area involvement

• Evidence of systemic toxicity

Prevention

Do's

• Store chemicals in original containers

• Wear protective gloves and clothing

• Read labels carefully

• Keep chemicals out of reach of children

Don'ts

• Transfer chemicals into drink bottles

• Remove product labels

• Leave hazardous chemicals unattended

• Store chemicals near food

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