TRIMELLITIC ANHYDRIDE-SENSITIVE MOUSE AS AN ANIMAL-MODEL FOR CONTACT URTICARIA

The respiratory allergen trimellitic anhydride (TMA) has been shown to induce IgE production and immediate ear swelling in mice sensitized t o it, We studied whether TMA sensitivity could be used as an animal mo del for immunological contact urticaria. BALB/C mice were sensitized t o TMA by topical applications. Groups of animals were pretreated on th e ears with the glucocorticosteroid (GCS) betamethasone-17,21-dipropio nate, the antihistamine (AH) diphenhydramine hydrochloride, the non-st eroidal anti-inflammatory drug (NSAID) indomethacin or vehicle (VEH), Ears were challenged with TMA and ear thickness was measured at baseli ne and 1, 2, 4, 8 and 24 h after challenge. Trimellitic anhydride caus ed a significant biphasic ear swelling response with an early peak at 1-2h, a plateau at 4h and a late peak at 24h, However, there was also an early swelling by TMA in non-sensitized mice, suggesting that non-i mmunological as well as immunological mechanisms contribute to early s welling by TMA, Glucocorticosteroid suppressed significantly the early and to some extent the late TMA responses, while AH suppresseI only e arly and NSAID only late TMA responses, Ear swelling in TMA-sensitive BALB/C mice may represent a combination of immunological and non-immun ological contact urticaria and allergic contact dermatitis. Mice sensi tive to TMA may be helpful in defining pharmacological agents affectin g contact urticaria and the model is perhaps suitable for identificati on of some immunologically mediated contact urticants. (C) 1997 by Joh n Wiley & Sons, Ltd.