8.1.3 Carbon monoxide (CO)-induced headache

Previously used term:

Warehouse workers’ headache.

Description:

Headache caused by exposure to carbon monoxide, resolving spontaneously within 72 hours after its elimination.

Diagnostic criteria:
  1. Bilateral headache fulfilling criterion C
  2. Exposure to carbon monoxide (CO) has occurred
  3. Evidence of causation demonstrated by all of the following:
    1. headache has developed within 12 hours of exposure to CO
    2. headache intensity varies with the severity of CO intoxication
    3. headache has resolved within 72 hours of elimination of CO
  4. Not better accounted for by another ICHD-3 diagnosis.
Comments:

Typically, carboxyhaemoglobin levels of 10-20% cause a mild headache without gastrointestinal or neurological symptoms, levels of 20-30% cause a moderate pulsating headache and irritability, and levels of 30-40% cause a severe headache with nausea, vomiting and blurred vision. At levels above 40%, headache is usually not a complaint because of the change in consciousness.

There are no good studies of the long-term effects of CO intoxication on headache, but there is some evidence of chronic post-CO intoxication headache.