  * This is the Consumer Version. *  Eosinophilic Disorders  by
Mary Territo, MD  Eosinophils usually account for less than 7%
of the circulating white blood cells (100 to 500 eosinophils per
microliter of blood). These cells have a role in the protective
immunity against certain parasites but also contribute to the
inflammation that occurs in allergic disorders.  An increased
number of eosinophils in the blood (eosinophilia) usually
indicates the response of the body to parasites or an allergic
reaction.  A low number of eosinophils in the blood
(eosinopenia) can occur with Cushing syndrome, stress reactions,
and treatment with corticosteroids but does not usually cause
problems because other parts of the immune system compensate
adequately.  Idiopathic hypereosinophilic syndrome  Idiopathic
hypereosinophilic syndrome is an uncommon disorder in which the
number of eosinophils increases to more than 1,500 cells per
microliter of blood for more than 6 months without an obvious
cause.  People of any age can dev