Experimental protocols.

<p>BALB/c mice were sensitized intra-peritoneally (IP) with 20 μg of midge extract (group I: midge-sensitized) or PBS (group II: controlled) on days 0, 7, 14 and 21 (n = 10 in each group). From day 28 to 35 the mice were intra-dermally (ID) sensitized with 10 μg of midge extract (group I) or PBS only (group II) on days 28, 31 and 35 (arrows). Serum samples were collected on days 0, 14, 28 and 42 as designated with inverted arrow heads. The scratching behaviours were videotaped on day 35 after the final sensitization. The mice were sacrificed on day 42.