Mast cell activation disease (MCAD)
This page gives a simplified introduction to the complex subject for those readers with no basic knowledge in medicine, biology and biochemistry. On the subpages of this page the individual aspects are then dealt with in greater detail.
Mast cells are a particular cell type which belongs to the immune system and is found in all body tissues. Mast cells in the human body have as similar function like the watchtowers of an ancient city. The guards are looking for foreign intruders. Once they perceive something suspicious, they will alert the soldiers in their neighbourhood by using chemical signal substances. The soldiers then will rush to the location where the attack takes place to fend off the danger. Histamine is the most important of over 200 neurotransmitters that serve the communication with surrounding cells.
The disease occurs when some of these "guardians" become overzealous, hypersensitive or too numerous, causing frequent or permanent false alarms. The affected organs or the whole body are then unreasonably put into a "state of war", as if it was attacked by a pathogen. The body is feeling sick and reacting with numerous symptoms to the supposed, but non-existent threat.
Mast cell disorders are probably very common, but can not yet be reliably diagnosed. It is estimated that between 5 and 17% of the total population are affected.