Allergy, histamine 1 receptor blockers, and the risk of multiple sclerosis.

Title
Allergy, histamine 1 receptor blockers, and the risk of multiple sclerosis.
Source
Neurology. 66(4):572-5, 2006 Feb 28.



BACKGROUND:

It is unclear whether allergic diseases are associated with multiple sclerosis (MS), but histamine 1 receptor blockers, used in the treatment of allergic conditions, decreased the severity of experimental autoimmune encephalomyelitis (an animal model of MS).

OBJECTIVE:

To assess the association of allergy history and use of histamine 1 receptor blockers with the risk of MS.

Histamine 1 receptor blockers (H1RBs) decrease the severity of experimental autoimmune (formerly allergic) encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Because these drugs are commonly used for the treatment of allergic conditions, it is conceivable that allergy and MS may share some risk factors. This hypothesis is indirectly supported by recent increases in the incidence of both allergic disorders and MS, and with the association of both conditions in individuals.

The identification of a link between allergy or H1RB use and MS could improve our understanding of MS physiopathology and help to develop new therapies. However, no studies have evaluated the relation between H1RB use and the development of MS in humans, and epidemiologic studies on the association between MS and allergic conditions provide conflicting results that are difficult to interpret because of design limitations.

CONCLUSION:

These results do not support a strong link between allergic conditions and multiple sclerosis (MS) risk but suggest a possible beneficial effect of antihistamines on the onset of MS.