Allergy to penicillin

Contaminants of high molecular weight (considered to have arisen from mycelial residues frxm the fermentation process) may be responsible for the induction of allergy to penicillins their removal leads to a marked reduction in the antigenicity of the... 

If a patient has a mild, delayed allergy to penicillin, first-generation cephalosporins are effective alternatives but should be avoided in patients with an immediate-type hypersensitivity reaction. 

Allergic manifestations The cephalosporins should be avoided or used with caution in individuals allergic to penicillins (about 5 to 15% show cross-sensitivity). In contrast, the incidence of allergic reactions to cephalosporins is 1-2% in patients without a history of allergy to penicillins. 

Many principles of antibiotic selection are illustrated by this patient. (1) His history of serious allergy to penicillin eliminated this entire family of antibiotics from consideration. Thus, when his dental abscess... 

Drug allergy, once it has occurred, is not necessarily permanent, e.g. less than 50% of patients giving a history of allergy to penicillin have a reaction if it is given again. 

Leg amputation, because there is a risk of gas gangrene in an ischaemic limb and the mortality is high (benzylpenicillin, or metronidazole for the patient with allergy to penicillin)... 

Hypersensitivity reactions are frequent early in a course of penicillamine, with urticarial or maculopapular rashes, fever, and lymphadenopathy. Cross-allergy to penicillin can occur. In addition, the use of penicillamine can be complicated by a unique variety of often serious autoimmune reactions, involving the skin, kidneys, liver, lungs, muscles, or other organs. Proteinuria is found in more than 10% of patients and sometimes develops into the nephrotic syndrome. Pemphigus, myasthenia gravis, polymyositis, or a lupus-like syndrome occur in smaller percentages. 

A 46-year-old man with diabetes mellitus and a history of allergy to penicillin, seafood, and soap had spinal anesthesia, and his systolic blood pressure fell to 90 mmHg (3). He was given 500 ml of gelafundin. Within minutes, he complained of pruritus along the drip site. There was no rash or urticaria, but the infusion was stopped immediately. He became restless, had copious oral secretions, complained of dyspnea, quickly... 

An extreme example reported in 1993 involved a 55-year-old obese man with no history of allergy to penicillin, who had on earlier occasions received sodium thiopental without reaction on this occasion he stopped breathing and had severe bronchial constriction and vascular collapse requiring prolonged resuscitation and mechanical ventilation (11). 

Labs His labs include serum creatinine (Cr) level 2.4 mg/dL, blood urea nitrogen (BUN) 44 mg/dL, fasting blood glucose (FBG) 85 mg/dL, white blood cell (WBC) count 18,000/mL. He is currently febrile at 38.5°C. He has an allergy to penicillin (rash and shortness of breath). 

Case Conclusion Because the etiology of intra-abdominal infections is most often polymicrobial (gram-negative and anaerobic bacteria) and the patient has an allergy to penicillin, FD can be treated empirically with tobramycin and metronidazole or clindamycin. This regimen provides adequate empiric coverage of the most noteworthy pathogens associated with intra-abdominal infections. 

MB is a 39-year-old man who is diagnosed with cellulitis. Since he has an allergy to penicillins (urticarial rash), he is prescribed clindamycin for 10 days. Nine days into therapy he develops diarrhea. A stool culture detects C difTidk toxin. What is the best treatment for MB s diarrhea ... 

Less chance of allergic reactions and can be used for patients with allergies to penicillin. 

If a patient has a mild, delayed allergy to penicillin, first-generation cephalosporins (such as cefazolin) are effective alternatives, but they should be avoided in patients with a history of immediate-type hypersensitivity reactions to penicillins (see Table 109-6). The potential for a true immediate-type allergy should be assessed carefully, and a penicillin skin test should be conducted before giving antibiotic treatment to any patient claiming an allergy. 

Pharyngitis, scarlet fever, erysipelas, and cellulitis caused by S. pyogenes and pneumonia caused by S. pneumoniae respond to macrolides. They are valuable alternatives for treatment of patients who have a serious allergy to penicillin. Unfortunately, macrolide-resistant strains are increasingly encountered. Penicillin-resistant strains of S. pneumoniae also are very likely to be resistant to macrolides. 

The penicillins are antibiotics that interfere with bacterial cell wall synthesis. The human body has no structures similar to the bacterial cell wall, so treatment with penicillins selectively destroys the bacteria, causing no harm to the patient. In practice, however, it must always be remembered that some individuals may develop an allergy to penicillins. 

The macrolides are valuable alternatives for treatment of patients who have a serious allergy to penicillin. Unfortunately, macrolide-resistant strains are increasingly encountered. 

Vancomycin is not in the penicillin family of medications. An allergy to penicillin would not prevent administering the vancomycin. 

Basomba A, Pelaez A, Villalmanzo IG, Campos A (1978) Allergy to penicillin unsuccessfully treated with a haptenic inhibitor (Benzylpenicilloyl-N-formyllysine BPO-Flys). A case report. Clin Allergy 8 341... 

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