Assessing allergy by measurement of serum immunoglobulin (Ig) E antibodies
is fast and safe to perform. Serum antibodies can preferably be assessed in
patients with dermatitis and in those who regularly use antihistamines and
other pharmacological agents that reduce skin sensitivity.
Skin tests represent the easiest tool to obtain quick and reliable informat
ion for the diagnosis of respiratory allergic diseases, It is the technique
more widely used, specific and reasonably sensitive for most applications
as a marker of atopy.
Measurement of serum IgE antibodies and skin-prick testing may give complim
entary information and can be applied in clinical and epidemiological setti
ngs.
Peripheral blood eosinophilia is less used, but is important in clinical pr
actice to demonstrate the allergic aetiology of disease, to monitor its cli
nical course and to address the choice of therapy. In epidemiology, hypereo
sinophilia seems to reflect an inflammatory reaction in the airways, which
may be linked to obstructive airflow limitation.