Contact Allergy to Two Aluminum Salts in Consecutively Patch-Tested Dermatitis Patients

Background Recently, aluminum chloride hexahydrate (ACH) 10.0% petrolatum (pet) was recommended for patch testing to detect aluminum contact allergy. Aluminum lactate (AL) may be as reliable a test substance as ACH. Objective We aimed to investigate the frequencies of aluminum allergy when ACH and AL were used in patch testing consecutive patients. Methods Petrolatum preparations of ACH 10.0% and AL 12.0% were added to the baseline series in 2010-2017. Aluminum chloride hexahydrate 10.0% pet was added to the children baseline series from July 1, 2012, to December 31, 2017. Results A total of 5448 patients were patch tested with the extended baseline series and 196 children with the extended children baseline series. Forty-eight of the 5448 adults (0.9%) and 10 of the 196 children (5.1%) were diagnosed with aluminum contact allergy. A significant difference was found between the aluminum allergy frequencies in children and adults patch tested with ACH in 2013-2017 (P < 0.001). The difference between the frequencies of contact allergies for the 2 aluminum salts is not statistically significant. Conclusions Patch testing with ACH and AL demonstrated similar contact allergy frequencies. To detect aluminum allergy, patch testing with ACH 10.0% pet is recommended. Aluminum chloride hexahydrate 10.0% pet should be considered for inclusion in baseline series for patch testing adults and children.