Facts on File Encyclopedia of Health and Medicine

nostic testing to rule out other possible causes of
the symptoms.

Treatment Options and Outlook

Antihistamine medications are the most effective
intervention early in the onset of a type I hyper-
sensitivity reaction, the classic allergic reaction.
These medications block histamine receptors on
cell membrane surfaces, effectively breaking the
chain reaction effect of the immune response. The
longer the hypersensitivity reaction has been
under way, the less effective antihistamine med-
ications are because the reaction moves beyond
histamine release and binding. Treatment for ana-
phylactic symptoms is injection with EPINEPHRINE, a
potent NEUROTRANSMITTERand HORMONEthat effec-
tively halts the immune response. Doctors reserve

epinephrine for life-threatening hypersensitivity

reactions because the drug has numerous and sig-

nificant effects on cardiovascular and pulmonary

function.

CORTICOSTEROID MEDICATIONS are effective for

severe type I reactions and type II, III, and IV reac-

tions. Other IMMUNOSUPPRESSIVE MEDICATIONSsuch

as methotrexate and cyclosporine act through dif-

ferent mechanisms to interrupt the immune

response. DISEASE-MODIFYING ANTIRHEUMATIC DRUGS

(DMARDS) use various mechanisms to achieve simi-

lar results. MONOCLONAL ANTIBODIES (MABS)are

showing great promise for treating hypersensitiv-

ity reactions in some people. The appropriate

treatment selections depend on the type and

severity of the hypersensitivity reaction and any

other health conditions the person may also have.

270 The Immune System and Allergies

TREATMENT OPTIONS FOR HYPERSENSITIVITY REACTION

Treatments Effects Effective for Type of Reaction
ANTIHISTAMINE MEDICATIONS block HISTAMINEbinding type I

CORTICOSTEROID MEDICATIONS suppress COMPLEMENT CASCADE, ANTIBODYactivation, type II, type III, type IV
and eosinophil production type I when severe or
suppress mast cell release of histamine, LEUKOTRIENES, nonresponsive to other treatment
and PROSTAGLANDINS

DISEASE-MODIFYING suppress various immune response pathways type III
ANTIRHEUMATIC DRUGS(DMARDS)

EPINEPHRINEinjection stop the immune response type I when severe or anaphylactic

immunosuppressive agents suppress various immune response pathways type III and type IV
other than corticosteroids

leukotriene receptor block leukotriene binding type I when ASTHMApresent
antagonist medications

MAST CELLstabilizers prevent degranulation within mast cells to block the type I when asthma present
release of histamine, leukotrienes, and prostaglandins

MONOCLONAL ANTIBODIES block antibody–ANTIGENbinding type I when asthma present
(MABS) type III and type IV

NONSTEROIDAL ANTI-INFLAMMATORY block the actions of prostaglandins type III
DRUGS(NSAIDS)