Prevalence of benzocaine and lidocaine patch test sensitivity in Denmark: temporal trends and relevance.

UNLABELLED: BACKGROUND. Allergens included in the European baseline series should result in positive patch test reactions in at least 1% of a patch test population. Inclusion of local anaesthetics other than benzocaine in the baseline series has previously been debated.

OBJECTIVES

To investigate temporal trends of benzocaine and lidocaine allergy in dermatitis patients who underwent routine patch testing in a tertiary referral patch test centre, and to clarify and discuss whether lidocaine and benzocaine should be included in routine series.

METHODS

Dermatitis patients who underwent routine patch testing with benzocaine as a part of the European baseline series between 1985 and 2010 (n = 19 347) and dermatitis patients who underwent routine patch testing with lidocaine between 1994 and 2001 (n = 6265) and between 2007 and 2009 (n = 1360) were included.

RESULTS

The overall prevalences of contact allergy were 0.5% (benzocaine), 0.3% (lidocaine for the period 1994-2001), and 0.14% (lidocaine for the period 2007-2009). Current relevance was observed in 10% of those with benzocaine allergy and in 5% of those with lidocaine allergy.

CONCLUSIONS

Benzocaine and lidocaine allergy is infrequent in Danish dermatitis patients. Lidocaine should only be used for aimed testing, and benzocaine should be removed from the baseline series used in Denmark.