Immediate hypersensitivity reaction to carboxymethylcellulose in lidocaine jelly and dimethicone drops: A case report and mini‐review

Excipient allergies are rare and difficult to diagnose. Carboxymethylcellulose (CMC, carmellose sodium) is an anionic water-soluble polymer derived from native cellulose, that is, used as excipient. Here, we report a case of urticaria caused by the CMC in lidocaine jelly dimethicone drops, which had for upper gastrointestinal endoscopy. widely pharmaceutical preparations, food additives, other pharmaceuticals, its use increasing. However, there few reports on immediate hypersensitivity reactions because substances containing CMC. Previous our suggest excipients, such CMC, can be potential hidden allergens.