Cefdinir allergy
Question:
12/3/2018
I saw a 16 year-old for penicillin and cephalosporin allergy. When he was three to four years old while on Amoxil for otitis, he developed a rash (not urticarial) and was switched to Omnicef. On the last day of treatment he developed a similar total body rash as when he was on Amoxil but also had swollen lower extremeity joints. No meds given but the swelling lasted 2 weeks and he was unable to walk during that time. His Penicillin testing and challenge was negative. He was negative to prick and ID to all 3 generations of Cephalosporins. Is the next step to give a single dose oral challenge with Cefdinir?
Answer:
Delayed reactions to all antibiotics are a challenge as there are multiple potential mechanisms. It is unlikely that delayed reactions, particularly when associated with persistent joint pain, are related to IgE or type I hypersensitivity. Serum sickness hypersensitivity may be associated with synovitis. If the reactions are due to IgG or IgM or T cells, the negative beta lactam/penicillin IgE test and challenge would not provide sufficient reassurance to permit routine administration. Antibiotic patch testing is a consideration to evaluate delayed, T lymphocyte dependent drug reactions (1). I do not think your patient is at risk of anaphylaxis. Thus, the antibiotic of need could be administered at routine oral dose with close follow up. I do not think a graded challenge or single oral dose challenge is necessary. However, I would consider administering 3-4 days of an oral antibiotic in an attempt to exclude a delayed reaction. I would not use cefdinir in light of the prolonged joint pain. The other option would be to use an alternative class, depending on the infection.
In summary, I do not think specific-IgE is likely responsible for the reactions suffered by your patient. The negative specific-IgE testing does not exclude delayed reactions. I would avoid cefdinir but consider an alternative beta lactam for an oral trial of several days to ensure the lack of a delayed reaction. Antibiotic patch testing may be of value but the technique is not standardized.
1. Solensky R, Khan D. Drug allergy: An updated practice parameter. Annals Allergy Asthma Immunol 2010;105:273.e1-78.
I hope this information is of help to you and your practice.
All my best.
Dennis K. Ledford, MD, FAAAAI