penicillin cephalosporin cross reactivity

Penicillin cephalosporin cross reactivity skin#

The most common clinical manifestation of both penicillin and cephalosporin allergy is skin reactions, occurring with a frequency of 1-3% of courses given. Non-immediate reactions such as maculopapular or morbilliform rashes are probably T-cell mediated. Immediate reactions are IgE mediated and classically manifest as anaphylaxis, urticaria, angioedema, bronchospasm and allergic rhinoconjunctivitis. Reactions to beta-lactam antibiotics can be classified into immediate and non-immediate. Over the last six months, the authors know of four cases from western Sydney including two deaths. However, reports of adverse outcomes, including fatalities, appear to be increasing. 1In clinical practice it is not uncommon for cephalosporins to be given to penicillin-allergic patients, particularly if the history of penicillin reaction was not life-threatening. Penicillins and cephalosporins exhibit partial and incomplete cross-reactivity of up to 7% that may be related to the 'generation' of cephalosporin. He remained stable on oral antihistamines and was discharged after three days. Hydrocortisone and antihistamines were given and he was admitted to hospital.Īs he was taking propranolol it was ceased, as beta blockers can potentiate further anaphylactic reactions. A diagnosis of anaphylaxis to cephalexin was made.

Wheeze and tongue swelling were absent and intra-abdominal pathology was excluded. On examination he had a generalised erythematous rash that was pruritic. Oxygen and intravenous fluids were given and in the emergency department his blood pressure was 140/70. The man had a documented history of amoxycillin allergy with pruritis.

He was prescribed cephalexin and had taken the first dose 10 minutes before collapsing. The man had seen his family doctor earlier that day complaining of sore throat, cough and haemoptysis. Ambulance officers noted impalpable blood pressure, shortness of breath and complaints of right-sided chest and epigastric pains.

Penicillin cephalosporin cross reactivity