Changes of skin temperature (T(o)) of the nose area during nasal provo
cation tests with histamine and allergen were followed by means of an
infrared thermography camera. By a colimator system in which temperatu
res measured on a given surface can be integrated and averaged, thermo
graphy allows the continuous and quantitative recording of the tempera
ture during the whole procedure in a completely noninvasive way. In 10
normal subjects, increasing doses of histamine induced a dose-depende
nt rise of the nose external temperature. No significant change was ob
served with the vehicle solution. In six subjects allergic to grass po
llen, the nebulization of increasing concentrations of a pollen extrac
t induced a dose-dependent rise in T(o). The T(o) rise observed after
histamine or allergen corresponded to a marked nasal obstruction. The
nebulization of the highest dose of the pollen extract did not induce
any T(o) rise in six nonallergic subjects. The continuous recording of
the skin temperature by a noninvasive method might yield additional i
nformation on the vascular changes rapidly occurring during nasal chal
lenges.