Background: The previously reported eotaxin overexpression in the lesional
skin of atopic dermatitis (AD) led us to the assumption that circulating le
vels of eotaxin may be elevated too. We sought to investigate the plasma ex
pression of eotaxin in children with skin allergy in relation to clinical a
ctivity and type of lesions.
Methods: Plasma cotaxin was assayed in 78 infants and children, of whom 16
had AD, 19 had acute urticaria (AU), and 43 were healthy matched subjects.
Seven children in the group of AU were resampled for plasma cotaxin after c
linical remission.
Results: The plasma eotaxin levels in AD (median = 158 pg/ml, mean [SD] = 1
68 [61] pg/ml) were significantly higher than the control values (median =
60 pg/ml, mean [SD]= 59.5 [18.5] pg/ml). Not only did patients with AU demo
nstrate elevated plasma eotaxin levels (median = 126 pg/ml, mean [SD] = 124
[33] pg/ml), but also a significant decline occurred on follow-up. The coe
xistence of angioedema with AU did not cause any further increase in plasma
eotaxin expression. Plasma eotaxin levels were significantly higher in AD
than in AU, probably reflecting the chronic nature of eczematous AD lesions
. The plasma eotaxin levels did not correlate with serum total I-E, periphe
ral blood absolute eosinophil count, or age of the patients. However, there
was a positive correlation between age and plasma eotaxin in the control g
roup.
Conclusions: Our findings imply that circulating levels of cotaxin increase
in AD and during flares of AU, probably to serve in the recruitment and ac
tivation of eosinophils. It may also represent a biomarker of lesional acti
vity.