[Anaphylaxis after injection of corticosteroid preparations--carboxymethylcellulose as a hidden allergen].

Two patients developed anaphylaxis after injection of a corticosteroid preparation containing carboxymethylcellulose (E466). In both cases skin tests yielded positive immediate type reactions to pure carboxymethylcellulose. This hydrophilic derivative of cellulose has found wide application in the pharmaceutical, cosmetics and food industry. The diagnosis is based on skin testing as 9% of the normal population was found to have serum IgE antibodies to this compound. In case of anaphylaxis after injection of corticosteroids, carboxymethylcellulose in addition to corticosteroids should be included for skin testing.