What are the other Names for this Condition? (Also known as/Synonyms)

• CO-Induced Headache
• Warehouse Workers’ Headache

What is Carbon Monoxide-Induced Headache? (Definition/Background Information)

• Carbon Monoxide (CO)-Induced Headache is described as a form of headache that occurs following exposure to carbon monoxide gas. The onset of the headache is typically within 12 hours of gas exposure, and a spontaneous resolution is noted within 3 days (following its elimination from the body)
• Carbon monoxide (CO) is a poisonous, colorless, odorless, and tasteless gas. Breathing in carbon monoxide is poisonous and can often be fatal. CO can form where there is a partial or incomplete combustion of fuels such as wood, kerosene, or natural gas
• When excess carbon monoxide gets accumulated in the air, the oxygen in the hemoglobin of the red blood cells gets replaced with the CO gas, forming carboxyhemoglobin. The severity of the headache is dictated by the levels of carboxyhemoglobin in blood
  • At 10-20% levels - mild headaches are noted; there are no neurological or gastrointestinal signs and symptoms
  • At 20-30% levels - a pulsating headache of moderate intensity is noted along-with irritability
  • At 30-40% levels - the headache is severe, and the affected individual may also present nausea, vomiting, and blurry vision
  • Over 40% levels - loss of consciousness may occur
• Individuals of any age group, gender, race, or ethnicity may be at risk for Carbon Monoxide-Induced Headache due to exposure to CO gas. However, young children are more at risk of gas poisoning than adults

The criteria for diagnosis of Carbon Monoxide (CO)-Induced Headache as outlined by the International Headache Society (IHS) is given below:

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

(Source: International Headache Society Classification ICHD-3, London, United Kingdom)