Background The link between various chronic skin disorders and
toxocariasis was previously demonstrated by case reports and several case-control studies. However, these previous studies were based only on the Toxocara canis excretory-secretory-
enzyme-linked
immunosorbent assay (
TES-ELISA) serological technique, which is not specific due to cross-reactivity with parasites of the genera Anisakis or Ascaris. Immunoblot analysis is highly specific and can detect very low levels of Toxocara
antibodies. Therefore, this technique may be useful in the identification of Toxocara
infection in patients with chronic skin disorders. Objectives Because
urticaria and
pruritus/
prurigo are skin conditions previously associated with
toxocariasis, we carried out a prospective study using both
TES-ELISA and Toxocara Western blot on 113 patients with either
chronic urticaria (n = 84) or chronic
pruritus (n = 29). Methods Patients were matched with controls according to gender, age and residence location (rural or urban area). Data were analysed using a Mantel-Haenszel chi(2) test. Results The proportion of positive
TES-ELISA results was not significantly different for patients with chronic skin disorders (
urticaria or
pruritus/
prurigo) from that of control subjects. However, the proportion of positive immunoblot results was significantly higher for patients with
chronic urticaria than for control subjects (P = 0.009). Conclusions Our study demonstrates the need to perform Western blotting immunodiagnosis, whatever the
TES-ELISA result, to improve diagnosis of human
toxocariasis in patients with
chronic urticaria caused by Toxocara
infection.