Related Experiment Videos
Contact urticaria from Emla cream.
J Waton1, A Boulanger, P H Trechot
1Dermatology Department, Fournier Hospital, Nancy, France.
Contact Dermatitis
|December 21, 2004
Summary
This study details the first reported case of immediate hypersensitivity to Emla cream, a common topical anesthetic. The reaction, presenting as urticaria, was specifically linked to lidocaine in Emla cream.
Area of Science:
- Dermatology
- Allergology
- Pharmacology
Background:
- Emla cream, a combination of lidocaine and prilocaine, is widely used as a topical anesthetic.
- Previous literature has documented various hypersensitivity reactions to its components, including anaphylaxis and contact dermatitis.
- Immediate-type hypersensitivity reactions to Emla cream have not been previously reported.
Observation:
- A 55-year-old woman developed urticaria shortly after applying Emla cream.
- Open application testing with Emla cream confirmed hypersensitivity.
- Diagnostic testing, including patch and prick tests, identified lidocaine as the causative agent.
Findings:
- The patient exhibited a positive patch test to lidocaine and a positive prick test to Emla cream.
- No cross-reactivity was observed with other tested local anesthetics.
- Intradermal and subcutaneous administration of alternative anesthetics were well-tolerated, enabling their safe use.
Implications:
- This case represents the first documented instance of immediate-type hypersensitivity (contact urticaria) to Emla cream.
- Lidocaine is identified as the specific allergen responsible for the urticarial reaction.
- The findings highlight the importance of considering Emla cream as a potential cause of acute allergic reactions and guide safe anesthetic choices in sensitized individuals.