nebulizer solutions are widely used in the treatment of asthma and chronic obstructive pulmonary disease .
a number of bronchial and nasal nebulizer preparations contain benzalkonium chloride ( bac ) ( 1 ) .
quaternary ammonium compounds are used as antiseptics , disinfectants , detergents , and preservatives , and of these bac is the most frequently used .
we report a 23-yr - old woman presenting with anaphylactic shock following an intradermal skin test with a nebulizer solution containing bac . as far as we could ascetain from available literatures ,
this is the first reported case of anaphylaxis caused by benzalkonium in a nebulizer solution .
a 23-yr - old woman who had complained of exacerbation of cough and dyspnea after inhalation therapy with a nebulizer solution was referred to our outpatient clinic .
she had been diagnosed with asthma 3 yr previously and treated with a metered dose of a short - acting b2-agonist inhaler as needed .
she had no history of anaphylaxis , urticaria , or drug allergy . on admission ,
her white cell count was 7,400/l with 5% eosinophils and the serum total ige was 256 iu / ml by the eia method .
on spirometry , her forced vital capacity and forced expiratory volume in 1 sec were 3,520 ml ( 90% of the predicted value ) and 2,700 ml ( 86% of the predicted value ) , respectively .
she underwent skin prick tests with a panel of 10 common inhalant allergens and histamine ( allergopharma co. , hamburg , germany ) and serial dilution of nebulizer solution containing bac ( ventolin , glaxosmithklein , u.k . ) .
the skin prick test was positive only for house dust mites species ( dermatophagoides farinae and d. pteronyssinus ) .
subsequently , an intradermal skin test with a serial dilution of her nebulizer solution was performed .
a positive reaction was observed with 1:10 solution ( wheal : 45 mm in diameter , flare : 1820 mm ) .
her blood pressure was 70/30 mmhg , and her pulse was 120 - 140 per minute .
she was resuscitated with a subcutaneous injection of epinephrine ( 0.5 mg ) , an intravenous infusion of saline , and oxygen .
after obtaining oral informed consent , two healthy women without atopy or allergies underwent intradermal skin tests with the same nebulizer solution .
one month later , we conducted a bronchial provocation test with bac following the method used by asmus et al .
the patient inhaled 3 ml of 0.9% nacl solution containing 600 g of bac ( benzalkonium chloride , sigma , st .
the solutions were prepared using aseptic techniques and stored at 2 in an eppendorf tube .
each 3 ml dose was inhaled using normal tidal breathing through a devilbiss 646 nebulizer ( devilbiss co. , somerset , pa , u.s.a . ) .
spirometry was performed at the beginning of the test and 15 min after inhalation of each dose began . on bac bronchial challenge ,
the patient refused skin test with bac since she was aware of her anaphylactic reaction .
this patient 's history and the results of the skin test and bac bronchial provocation test are consistent with anaphylaxis caused by a nebulizer solution containing bac .
our case showed a positive skin test to nebulizer solution and developed an anaphylactic reaction .
although a positive bronchial provocative response to bac is not specific to diagnosis of bac - induced anaphylaxis , the immediate development of symptoms and bronchoconstriction in response to bac were significant in this case .
bac is one of the best known etiologic causes of contact dermatitis and occupational asthma .
it is found in cosmetics , soaps , baby lotions , body lotions , and skin care products , as well as in medical products , such as eye drops , ointments , and solutions .
some bronchial nebulizer solutions contain bac as a bactericidal preservative , and it causes paradoxical bronchoconstriction in some asthmatics when inhaled .
the mechanism of the allergic reaction caused by bac and other chemicals remains controversial ( 3 ) .
the previous reports on bac - induced asthma suggest that it induces anaphylaxis via either ige - mediated or non - ige mediated mechanisms .
our case showed a positive intradermal test , suggesting that an ige - mediated mechanism played a role in causing the reaction .
however , this does not exclude the possibility that bac also causes non - specific histamine release from mast cells via surface activation .
this is supported by previous reports of dose - dependant histamine release from rat mast cells , and antihistamine inhibition of the bronchoconstriction caused by bac ( 4 , 5 ) . in conclusion ,
our patient had an anaphylactic reaction caused by the intradermal injection of benzalkonium chloride in her nebulizer solution .
although this is not a common complication , such reactions may occur in patients treated with nebulized solutions containing bac .
 benzalkonium chloride ( bac ) is commonly used as a bactericidal preservative in nebulizer solutions , and can cause paradoxical onchoconstriction following nebulizing therapy in some asthmatics . 
 we describe a case of anaphylactic shock in a 23-yr - old asthmatic woman following an intradermal skin test with a salbutamol solution containing bac . 
 since she complained of cough and dyspnea after inhalation therapy with a nebulizer solution , we conducted an intradermal skin test using the same solution , which contained bac . 
 about 10 min later , the patient reported dizziness , palpitations , and dyspnea . on examination , tachycardia , 
 tachypnea , and hypotension were found . 
 she was resuscitated with a subcutaneous injection of epinephrine and an infusion of saline . 
 one month later , we conducted a bronchial provocation test with bac , and she showed a positive response . 
INTRODUCTION
CASE REPORT
DISCUSSION