History and exam

Key diagnostic factors

common

presence of risk factors

Key risk factors include history of self-harm or recent interpersonal conflict, mental illness, alcohol or drug abuse, and pesticide availability and ease of access.

increased secretions

Severe bronchorrhoea may be seen and is diagnostic.

Excessive lacrimation and salivation also occur.

fasciculations

These are much more noticeable early on and are diagnostic. They usually occur in peri-orbital, chest, or leg muscles, and are not responsive to atropine.

pinpoint pupils

These are almost universally present in severe cases prior to atropine treatment and do not respond to naloxone (an opioid receptor antagonist used in the treatment of opioid overdose).

distinctive odour

Distinctive odour of solvent can often be detected on a patient.

chest crackles and rhonchi

Widespread wheezes and crackles indicate bronchospasm and pulmonary oedema.

semi-conscious/coma

Patient may be semi-conscious at presentation; coma indicates a worse prognosis.

Other diagnostic factors

common

visual disturbances

Patient may report blurred vision.

vomiting

Nausea and vomiting are common muscarinic symptoms of organophosphate poisoning.

influenza-like syndrome

Exposure, even dermal, may result in an influenza-like syndrome (e.g., fatigue, runny nose, headache, dizziness, anorexia, sweating, diarrhoea, and muscle weakness).

urinary or faecal incontinence

Patient may report incontinence, or it may be a sign on presentation if a patient is semi-conscious or confused.

proximal muscle weakness

This may occur early on, or after other signs are resolving. It is not responsive to atropine.

abnormal deep tendon reflexes

Frequently increased early on, and decreased or absent later. It is not responsive to atropine.

abnormal heart rate

Extreme bradycardia or tachycardia may be seen.

abnormal blood pressure

Hypertension may be seen. Refractory hypotension is a far more concerning sign, indicating a grave prognosis.

decreased respiration

Oxygen saturation is usually low. Respiratory failure is more common with severe poisoning.

hypothermia

Mild to moderate hypothermia is often present on admission if atropine treatment has not been given.

uncommon

seizures

Seizures are more common with severe poisoning.

delayed-onset central nervous system and peripheral (predominantly motor) neuropathy

Onset is 1 to 5 weeks. The neuropathy may be severe and can lead to permanent disability. It may also have upper motor neuron disease features.

Risk factors

strong

pesticide availability

A major factor determining the frequency with which fatal and non-fatal acute pesticide poisoning occurs in various countries.[4]

history of self-harm or recent interpersonal conflict

Consistently found to be a risk factor (for deliberate self-poisoning with pesticides) across all cultures.[5][6][7][8]

mental illness

Consistently found to be a risk factor (for deliberate self-poisoning with pesticides) across all cultures.[5][6][7][8]

alcohol or drug abuse

Consistently found to be a risk factor (for deliberate self-poisoning with pesticides) across all cultures.[5][6][7][8]

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