Delayed hypersensitivity due to epidural block with ropivacaine.

Ropivacaine, introduced in 1995, is an amide-type local anaesthetic. It consists of pure optical S-(-)-isomers and has a low cardiotoxicity. We report delayed hypersensitivity reactions to ropivacaine. A 74 year old man with postherpetic neuralgia started taking amitriptyline, alprazolam, and loxoprofen and underwent an epidural block with 0.2% ropivacaine hydrochloride without preservatives (48 ml or 96 ml daily). He had no history of allergy to any local anaesthetics. Two weeks later, purpuric rash appeared on his legs, and two days afterwards he developed a widespread blotchy erythema on his trunk and arms (figure). Laboratory examination showed normal white cell and platelet counts and slight eosinophilia (640/mm). The epidural block and the drugs were stopped, and the eruptions completely resolved within seven days. We did an intradermal test with 0.2% ropivacaine from a plastic ampoule without a rubber stopper. Erythema (maximum size was 23 mm×13 mm) appeared 8-72 hours after the injection. We did the test again and took a specimen for biopsy. Histology showed perivascular infiltrates of lymphocytes and eosinophils in the dermis. Patch testing with amitriptyline, alprazolam, and loxoprofen induced no eruptions, nor did restarting the drugs. Eleven cases of delayed-type hypersensitivity reactions have been reported, caused by local injections of amides such as lignocaine, mepivacaine, and prilocaine. The symptoms were erythema, papules, vesicles, and swelling, but they did not include purpuric rash. No cases related to an epidural block or ropivacaine have been reported. Ropivacaine may cause allergic reactions characterised by signs such as urticaria, angioneurotic oedema, tachycardia, and vomiting, but delayed hypersensitivity reactions are not referred to in the Physicians’ Desk Reference. The manufacturer also has had no similar reports. Contributors:MB wrote the paper, searched the literature, and is guarantor. MH accessed the manufacturer and elaborated on the paper.