- Headache, in a person affected by a primary headache disorder, and with the characteristics of that headache type, fulfilling criterion C
- Histamine has been administered
- Evidence of causation demonstrated by both of the following:
- headache has developed within 2-12 hours after administration of histamine
- headache has resolved within 72 hours after administration of histamine
- Not better accounted for by another ICHD-3 diagnosis1.
Phenomenologically, 220.127.116.11 Delayed histamine-induced headache resembles the patient’s primary headache type, but is regarded as secondary, attributed to the drug. The patient should be coded both for the primary headache and 18.104.22.168 Delayed histamine-induced headache.
While 22.214.171.124 Delayed histamine-induced headache occurs only in a person affected by a primary headache disorder and phenomenologically resembles that headache type, it is presumed that it is mechanistically distinct.