[Tolerability of oral administration of carboxymethylcellulose in two patients presenting anaphylactic reaction after carboxymethylcellulose injection].

BACKGROUND

Carboxymethylcellulose is a high-molecular-weight polysaccharide molecule used as a binding agent, for coating molecules and to increase the viscosity of formulations. It is present in a large number of pharmaceutical products but is also found in food and cosmetics.

CASE-REPORT: We report two cases of patients who presented anaphylactic reactions immediately after localised corticosteroid injections; intra-articular for the first and intralesional for the second. Allergological testing for different corticosteroids and carboxymethylcellulose by means of prick-tests and intradermal testing indicated that the immediate hypersensitivity reaction was caused by the excipient, carboxymethylcellulose. The excellent safety of oral reintroduction of carboxymethylcellulose in a pharmaceutical preparation in these two patients confirmed that this large molecule is not absorbed through the digestive system.

DISCUSSION: The avoidance list of products containing carboxymethylcellulose could be greatly reduced and limited to only injectable pharmaceutical preparations containing carboxymethylcellulose and to oral contrast media containing large quantities of carboxymethylcellulose.