Skin symptoms | ||
Symptom | Mediators | Mechanism |
Flushing | Histamine (H1), PGD2 | Increased vasodilation and permeability of blood vessels
Blood is closer to the skin and redness is seen |
Itching | Histamine (H1), leukotrienes LTC4, LTD4, LTE4, PAF | Possibly stimulation of itch receptors or interaction with local neurotransmitters |
Urticaria | Histamine (H1), PAF, heparin, bradykinin | Increased vasodilation and permeability of blood vessels and lymphatic vessels
Fluid is trapped inappropriately between layers of skin |
Angioedema | Histamine (H1), heparin, bradykinin, PAF | Increased vasodilation and permeability of blood vessels and lymphatic vessels
Fluid is trapped inappropriately between layers of tissue |
Respiratory symptoms | ||
Symptom | Mediators | Mechanism |
Nasal congestion | Histamine (H1), histamine (H2), leukotrienes LTC4, LTD4, LTE4 | Increased mucus production
Smooth muscle constriction |
Sneezing | Histamine (H1), histamine (H2), leukotrienes LTC4, LTD4, LTE4 | Increased mucus production
Smooth muscle constriction |
Airway constriction/ difficulty breathing | Histamine (H1), leukotrienes LTC4, LTD4, LTE4, PAF | Increased mucus production
Smooth muscle constriction |
Cardiovascular symptoms | ||
Symptom | Mediators | Mechanism |
Low blood pressure | Histamine (H1), PAF, PGD2, bradykinin | Decreased force of heart contraction
Increased vasodilation and permeability of blood vessels Impact on norepinephrine signaling Change in heart rate |
Presyncope/syncope (fainting) | Histamine (H1), histamine (H3), PAF, bradykinin | Increased vasodilation and permeability of blood vessels
Decrease in blood pressure Dysfunctional release of neurotransmitters |
High blood pressure | Chymase, 9a,11b-PGF2, renin, thromboxane A, carboxypeptidase A | Impact on renin-angiotensin pathway
Impact on norepinephrine signaling Tightening and decreased permeability of blood vessels |
Tachycardia | Histamine (H2), PGD2 | Increasing heart rate
Increasing force of heart contraction Impact on norepinephrine signaling |
Arrhythmias | Chymase, PAF, renin | Impact on renin-angiotensin pathway
Impact on norepinephrine signaling |
Gastrointestinal symptoms | ||
Symptom | Mediators | Mechanism |
Diarrhea | Histamine (H1), histamine (H2), bradykinin, serotonin | Smooth muscle constriction
Increased gastric acid secretion Dysfunctional release of neurotransmitters |
Gas | Histamine (H1), histamine (H2), bradykinin | Smooth muscle constriction
Increased gastric acid secretion |
Abdominal pain | Histamine (H1), histamine (H2), bradykinin, serotonin | Smooth muscle constriction
Increased gastric acid secretion Dysfunctional release of neurotransmitters |
Nausea/vomiting | Histamine (H3), serotonin | Dysfunctional release of neurotransmitters |
Constipation | Histamine (H2), histamine (H3), serotonin (low) | Dysfunctional release of neurotransmitters |