Skin Testing for Ceftriaxone in a 1-Month-Old Infant
Skin testing for ceftriaxone can be performed in a 1-month-old baby when evaluating for drug allergy, though the evidence base is limited in this age group. 1, 2
Clinical Context for Skin Testing
Skin testing for beta-lactam antibiotics, including cephalosporins, serves as a diagnostic tool when drug allergy is suspected. The CDC guidelines acknowledge that skin testing may be helpful in some patients and settings when evaluating penicillin allergy, though they note insufficient data regarding ceftriaxone specifically. 1
Evidence Supporting Skin Testing in Pediatrics
Recent case reports demonstrate successful skin testing with ceftriaxone in pediatric patients, including a 13-year-old who had positive skin tests for ceftriaxone after anaphylaxis, while testing negative for other cephalosporins. 2
Skin testing protocols typically include both penicillin and specific cephalosporin testing to identify cross-reactivity patterns and guide safe antibiotic selection. 2
The diagnostic approach combines skin testing with the suspected antibiotic and oral challenge when appropriate, recognizing that 58-75% of pediatric patients with suspected cephalosporin allergy may be delabeled with proper protocols. 2
Important Caveats for Neonates
The primary concern with ceftriaxone in 1-month-old infants is NOT allergy testing, but rather the drug's contraindications in this age group:
Ceftriaxone is contraindicated in neonates ≤28 days if they require calcium-containing IV solutions due to precipitation risk. 3
Hyperbilirubinemic neonates should not receive ceftriaxone as it can displace bilirubin from albumin binding, risking bilirubin encephalopathy. 3
At 1 month of age (approximately 30 days), the infant is technically beyond the neonatal contraindication period for calcium-containing solutions, though caution remains warranted for hyperbilirubinemia. 3
Practical Approach to Skin Testing
If skin testing is clinically indicated for suspected ceftriaxone allergy in a 1-month-old:
Perform skin prick testing first, followed by intradermal testing if negative, using standardized concentrations when available. 2
Include penicillin G testing as it has demonstrated utility with negative predictive value up to 95.2% when combined with controlled challenge, and can help identify cross-reactivity patterns. 2
Consider testing alternative cephalosporins with different R1 side chains to identify safe alternatives if ceftriaxone allergy is confirmed. 2
Recognize that basophil activation testing (BAT) has variable sensitivity (38-75%) and may not be readily available in all settings. 2
Clinical Decision-Making
The decision to perform skin testing should weigh the clinical necessity of ceftriaxone versus alternative antibiotics:
For most neonatal infections, ampicillin plus gentamicin remains the standard presumptive regimen and avoids the need for cephalosporin exposure. 4
When cephalosporin coverage is required and ceftriaxone allergy is suspected, cefepime should be considered as an alternative rather than ceftazidime monotherapy, which is inappropriate for presumptive neonatal infection management. 4
The contraindication data for ceftriaxone in neonates remain limited, and some experts suggest it could be considered in low-risk infants without hyperbilirubinemia or calcium exposure on a case-by-case basis. 4