Penicillin allergic reactions

The possible role of fungal infections in the development and/or persistence of penicillin allergic reactions has been emphasized (Feinberg 1944 Schuppli 1958, 1962 Blum and de Weck 1966). 

Allergy to penicillins is a fairly common phenomenon and is estimated to occur in 2—8% of patients (1, 3 ). Probably due to the repeated and frequent use of penicillins, allergic reactions have become increasingly frequent and severe. It is estimated that approximately 3000 anaphylactic reactions occur annually, of which 10% are fatal (2 ). One reviewer (2 ) has interpreted the evidence to date as suggesting that severe reactions are most likely to occur in patients with a history of atopic asthma, hay fever, or atopic dermatitis. This opinion has also been recently ventured by Parker (5 ). However, the opposite view is put forward by Horowitz (6 ) this author cites a study by Green et al. (1971) on 1027 patients in which it was found that there was no correlation between penicillin reactions (or sensitivity) and a family or personal history of allergy. According to Horowitz this study has since been extended to cover somewhat more than 3000 patients. 

The cephalosporins generally cause few side effects (80,132,219—221). Thrombophlebitis occurs as a result of intravenous administration of all cephalosporins. Hypersensitivity reactions related to the cephalosporins are the most common side effects observed, but these are less common than found with the penicillins. Clinically only about 5—10% of patients with allergic reactions to the penicillins manifest the same reactions to the cephalosporins, and data would contradict any tme cross-reactivity to cephalosporins in patients who have previously reacted to penicillin (80,132,219). 

The penicillins in general, ate renowned for their lack of toxicity. The most common adverse effect of the use of penicillins is an allergic reaction which can change from a mild rash to fatal anaphylactic shock in rate cases. AH penicillins cross the placenta and ate excreted in maternal milk. However, the relative freedom from toxicity tenders these compounds valuable agents during pregnancy and lactation. 

A hypersensitivity (or allergic) reaction to a drug occurs in some individuals, especially those with a history of allergy to many substances. Signs and symptoms of a hypersensitivity to penicillin are highlighted in Display 7-3. 

Some types of allergic reaction, for example immediate or delayed-type skin allergies, serum-sickness-like reactions and anaphylactic reactions, may occur in a proportion of patients given penicillin treatment. There is some, but not complete, cross-allergy with cephalosporins. 

Lactamases Bacillus cereus (or other bacteria, as appropriate) Sterility testing, treatment of penicillin-induced allergic reaction 2.4.4, 4.5... 

In penicillin-allergic patients, oral or parenteral clindamycin may be used. Alternatively, a first-generation cephalosporin such as cefazolin (1 to 2 g IV every 6 to 8 hours) may be used cautiously for patients who have not experienced immediate or anaphylactic penicillin reactions and are penicillin skin test negative. In severe cases in which cephalosporins cannot be used because of documented methicillin resistance or severe allergic reactions to /1-lactam antibiotics, IV vancomycin should be administered. 

Q34 Wh ich of the follov/ing drugs should be used v/ith utmost caution in o patient v/ho hod o severe allergic reaction to penicillin ... 

The two major questions concerning the use of antibiotics in agriculture are the safety of the residues in the animal-derived food and the antibiotic resistance that may develop from the use of these drugs in animals. I will not talk about antibiotic resistance as Mr. Frappaolo discusses this issue in a separate paper. The residue issue can be further divided into the toxicity and the allergic reaction to the drug residues. There is sufficient concern for the allergic reaction to penicillin that its tolerance is based upon this concern however, the rest of the antibiotics have tolerances based on toxicity other than the allergic reaction. 

Hypersensitivity reactions Make careful inquiry for a history of hypersensitivity reactions. Monitor patients who have had immediate hypersensitivity reactions to penicillins or cephalosporins. If an allergic reaction occurs, discontinue the drug and institute supportive treatment. Cross-sensitivity with other penicillins or -lactam antibiotics is rare. 

The incidence of nonallergic ampicillin eruptions is 40 to 100% in patients with concomitant Epstein-Barr virus (mononucleosis), cytomegalovirus, acute lymphocytic leukemia, lymphoma, or reticulosarcoma. Nonallergic penicillin-associated rashes are characteristically morbilliform (symmetrical, erythematous, confluent, maculopapular) eruptions on the extremities. The onset of typical nonallergic eruptions is more than 72 hours after (3-lactam exposure. The mechanism for the nonurticarial ampicillin rash is not known and is not related to IgE or type I hypersensitivity. Penicillin skin tests are not useful in the evaluation of nonurticarial ampicillin rashes. Patients with a history of nonurticarial ampicillin rashes may receive other (3-lactam antibiotics without greater risk of subsequent serious allergic reactions. 

Does not identify those patients who react to a minor antigenic determinant (i.e., anaphylaxis) does not reliably predict the occurrence of late reactions patients with a negative skin test may still have allergic reactions to therapeutic penicillin... 

Penicillin-allergic patients tolerate aztreonam without reaction. Occasional skin rashes and elevations of serum aminotransferases occur during administration of aztreonam, but major toxicity has not yet been reported. In patients with a history of penicillin anaphylaxis, aztreonam may be used to treat serious infections such as pneumonia, meningitis, and sepsis caused by susceptible gram-negative pathogens. 

Penicillin and its derivatives are very widely used antibiotics, which are well tolerated and have a low acute toxicity. Doses as high as 1 g kg-1 day-1 can be given by intravenous injection. However, penicillin and related derivative drugs cause more allergic reactions than any other class of drug. The incidence of allergic reactions to such drugs occurs in at least 1% of recipients. 

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