History and exam
Key diagnostic factors
common
presence of risk factors
Ingestion of ≥125 mg/kg salicylate
In the UK, the National Poisons Information Service recommends that children and adults who might have ingested ≥125 mg/kg salicylate, or those who are symptomatic, should be assessed for toxicity.[2]
Ingestion of any amount of oil of wintergreen[1][5]
Oil of wintergreen is 98% methyl salicylate, and its ingestion carries a substantial risk of salicylate poisoning.
Found in some topical liniments and non-prescription medications.
Ingestion of bismuth subsalicylate[1][2]
Many non-prescription antidiarrhoeal medications contain bismuth subsalicylate, a 50% aspirin equivalent.
Salicylate overdose from these products is rare.
History of self-harm or suicide attempt[1]
Salicylate-containing products may be ingested intentionally in overdose as a means of self-harm or with suicidal intent.[5] See Suicide risk mitigation.
Children aged ≤3 years and adults aged ≥70 years
Incorrect salicylate dosing in children and older people can result in toxic salicylate exposure.
Accidental ingestion is also of particular concern at extremes of age.[5]
unknown toxin ingestion or exposure
Consider salicylate poisoning in all patients with a history of toxin ingestion or topical exposure, particularly in the presence of an unexplained metabolic acidosis.
confusion, disorientation, agitation
nausea, vomiting, epigastric pain
fever, sweating, warm extremities, bounding pulses
dyspnoea
Predominant shortness of breath associated with a history of suspected poisoning should alert the physician to the possibility of an underlying metabolic acidosis and/or respiratory alkalosis.[1] May reflect onset of acute respiratory distress syndrome, which, although not common, can be life-threatening and reflects severe poisoning.[1][2] Shortness of breath may be the only presenting symptom.
May also indicate chronic poisoning.
tachypnoea, hyperventilation, Kussmaul's respirations
Salicylates stimulate the respiratory centre directly and cause tachypnoea in early salicylate poisoning.[1][2]
Respiratory alkalosis is, therefore, a feature of early salicylate poisoning. Metabolic acidosis, when it develops, also stimulates a compensatory respiratory response. Respiratory signs may be the only presenting features.
tinnitus and/or deafness
Mild central nervous system effects usually present in early stages of acute ingestion.[1] Tinnitus is commonly present as a clinical symptom indicating onset of potential salicylate toxicity. Tinnitus is so common at salicylate levels of 20 mg/dL (1.45 mmol/L) or more that it can be used to gauge presence of excess intake.[1] Tinnitus and deafness resolve as salicylate levels fall.
malaise and/or dizziness
movement disorders, asterixis, stupor
Neurological toxicity may be the only presenting sign or symptom. Substantial neurological toxicity indicates severe poisoning.[1]
confusion and/or delirium (irritability, hallucinations, deterioration in activities of daily living)
Neurological toxicity may be the only presenting sign or symptom, with confusion and delirium occurring particularly in chronic or subacute ingestions.[1] Substantial neurological toxicity indicates severe poisoning.
coma and/or papilloedema
Neurological toxicity may be the only presenting sign or symptom. It can extend beyond tinnitus and mild confusion to life-threatening manifestations such as coma and cerebral oedema (papilloedema is suggestive but neither a sensitive nor a specific finding).[1] Indicates severe or chronic poisoning and is associated with death.[1][2]
More common in children.[2]
uncommon
Other diagnostic factors
common
volume depletion/dehydration
Indicates moderate poisoning.[2] Common though non-specific sign, including dry mucous membranes and poor skin turgor. Central volume depletion may not be obvious in a patient with diaphoresis.
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