XIII - β-lactam antibiotics

https://doi.org/10.1016/S0091-6749(18)30578-5Get rights and content

Section snippets

SUMMARY STATEMENTS

  • Penicillin is the most frequent cause of anaphylaxis in humans and has been estimated to be responsible for 75% of anaphylactic deaths in the United States.

  • Although allergic reactions may occur after administration of penicillin by any route, parenteral administration is most likely to induce severe reactions such as anaphylaxis. Oral administration appears considerably safer.

  • Patients with a history of a prior penicillin reaction are six times more likely to experience a reaction on subsequent

Epidemiology

Penicillin is the most frequent cause of anaphylaxis in humans1 and has been estimated to be responsible for 75% of anaphylactic deaths in the United States.2 Most deaths from penicillin anaphylaxis have occurred among individuals with no history of atopic disease.3 Anaphylactic reactions to penicillin occur most commonly in adults between the ages of 20 and 49 years, although such reactions have occurred in both children and the elderly.4 A fatal outcome, however, may be more likely in the

EVALUATION OF PENICILLIN ALLERGY

Although the history alone is not diagnostic of penicillin hypersensitivity, it may be helpful in the initial assessment. Patients with a history of prior penicillin reaction are six times more likely to experience a reaction on subsequent exposure compared with those without a previous history.8 Nevertheless, there are reasons why a previous history of penicillin hypersensitivity may not be reliable. For example, minor rashes in childhood may be misdiagnosed as penicillin allergy. In addition,

SELECTION OF PATIENTS FOR PENICILLIN SKIN TESTING

Patients with a history of a possible allergic reaction to penicillin who have recommended indications for penicillin treatment should be skin tested. This includes patients with a history of anaphylaxis, urticaria, or other rashes, as well as patients with unknown childhood or adult reactions. Individuals who have experienced anaphylaxis to penicillin cannot be reliably skin tested for 1 to 2 weeks or longer after the reaction.17, 18 Skin testing is generally not recommended for a patient with

RISKS OF ANAPHYLAXIS FROM SKIN TESTING

By using the above reagents and proper technique by skilled personnel, serious reactions, including anaphylaxis and death, are extremely rare. Nevertheless, anaphylactic reactions and deaths from penicillin skin testing have been reported. However, these were all caused by administration of higher than recommended doses or intracutaneous testing not preceded by prick/puncture testing. Use of penicillin skin test reagents does not appear to resensitize the patient.

TREATMENT ON THE BASIS OF SKIN TEST RESULTS

If the patient has a past history of an allergic reaction to penicillin and the skin test response is positive to either major or minor determinants, the patient should receive an alternate antibiotic unless the indication for penicillin is clear. If administration of penicillin is mandatory in this setting, desensitization is indicated.

Although the patient does not need to undergo test dosing before receiving a full therapeutic dose. If skin test responses to a mix of minor determinants (if

SPECIAL PROBLEMS

Administration of ampicillin and amoxicillin is associated with the development of morbilliform rashes in 5% to 13% of patients. These patients should not be considered at risk of a life-threatening reaction to penicillin and therefore do not require skin testing. On the other hand, if the rash to ampicillin or amoxicillin is urticarial, or if the patient has a history of anaphylaxis, the patient should undergo penicillin skin testing before a future course of penicillin is given.

Carbapenems

CEPHALOSPORIN ALLERGY

Cephalosporins and penicillins have a common β-lactam ring structure, and varying degrees of cross-reactivity have been documented. However, the risk of allergic reactions to cephalosporins in patients allergic to penicillin appears to be low (less than 10%). First generation cephalosporins may pose a greater risk than second or third generation cephalosporins. Some anaphylactic reactions to cephalosporins may be due to antibodies directed against specific side chains in these molecules rather

ADMINISTRATION OF CEPHALOSPORINS TO PATIENTS WITH A HISTORY OF ALLERGY TO PENICILLIN

If a patient has a questionable history of penicillin allergy and requires a cephalosporin, penicillin skin testing can be considered to ensure the absence of penicillin-specific IgE antibodies. If a patient has a history of an immediate systemic reaction to penicillin, skin testing to major and minor determinants of penicillin should be done to determine if the patient has penicillin-specific IgE antibodies. If skin test responses are negative, the patient can receive the cephalosporin at no

ADMINISTRATION OF PENICILLIN TO A PATIENT WITH A HISTORY OF ALLERGY TO A CEPHALOSPORIN

Patients with a history of IgE-mediated reactions to a cephalosporin who require penicillin should undergo penicillin skin testing. If the test responses are negative, they can receive penicillin; if positive, they should either receive an alternative medication or undergo desensitization to penicillin.

ADMINISTRATION OF A CEPHALOSPORIN TO A PATIENT WITH A PAST HISTORY OF ALLERGY TO A CEPHALOSPORIN

If a patient with a past history of allergy to one cephalosporin requires treatment with another cephalosporin, skin testing with the required cephalosporin can be done, recognizing that the negative predictive value is unknown. If the skin test response for the cephalosporin is positive, control subjects can be tested to determine if the positive response was due to irritation or was possibly IgE-mediated. Skin testing should be done with a prick/puncture technique and possibly be followed by

REFERENCES (18)

There are more references available in the full text version of this article.

Cited by (0)

View full text