Detection of IgE antibodies to bacitracin using a commercially available streptavidin-linked solid phase in a patient with anaphylaxis to triple antibiotic ointment.
BACKGROUND
Bacitracin is a commonly used topical antibiotic that has on occasion been reported to cause anaphylaxis. Evidence of the role of bacitracin specific IgE in such reactions has been demonstrated by skin testing. Because of the potential for provoking a systemic reaction by skin testing, it would be advantageous to develop an in vitro test for bacitracin specific IgE.


OBJECTIVE
To report our experience coupling bacitracin to a solid phase and using it to detect specific IgE to bacitracin by fluorescent enzyme immunoassay.


METHODS
A patient with a history of recurrent anaphylaxis that developed after application of triple antibiotic ointment to an open wound underwent skin testing with triple antibiotic ointment. Bacitracin was biotinylated and coupled to streptavidin ImmunoCAPs. IgE against bacitracin in the patient's serum was detected by fluorescent enzyme immunoassay.


RESULTS
Topical application of triple antibiotic ointment to intact skin produced a 7 X 8-mm wheal with pseudopods. IgE against bacitracin was detected using biotinylated bacitracin-streptavidin ImmunoCAPs at a level of approximately 0.6 KUA/L and confirmed with ImmunoCAPs using direct coupling of bacitracin to the solid phase.


CONCLUSIONS
We demonstrate the presence of IgE antibodies to bacitracin in a patient with anaphylaxis to triple antibiotic ointment using a recently described procedure for producing custom allergen solid phases for immunoassay.
Sharif
Saba
S
Kaiser Permanente, Los Angeles Medical Center, Los Angeles, California, USA. ssharifusa@yahoo.com
Goldberg
Bruce
B
D000707:Anaphylaxis / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis*; D000891:Anti-Infective Agents, Local / Q000009:adverse effects* / Q000276:immunology; D001414:Bacitracin / Q000009:adverse effects* / Q000276:immunology; D019921:Biotinylation; D004338:Drug Combinations; D004342:Drug Hypersensitivity / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009355:Neomycin / Q000009:adverse effects; D011112:Polymyxin B / Q000009:adverse effects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012882:Skin Tests; D019809:Streptavidin
D000891:Anti-Infective Agents, Local; D004338:Drug Combinations; D001414:Bacitracin; D007073:Immunoglobulin E; C001816:bacitracin zinc, neomycin sulfate, polymyxin B, drug combination; D019809:Streptavidin; D009355:Neomycin; D011112:Polymyxin B