Intravenous penicillin desensitization and treatment during pregnancy

Untreated syphilis during pregnancy may result in stillbirth in one fourth of cases, while in infants who survive, there may be serious immediate and delayed manifestations. Penicillin is the drug of choice for treating both mother and fetus. We describe a woman with an allergy against both major and minor determinants of penicillin in whom syphilis was diagnosed on routine obstetric screening. Her obstetric history included one vaginal delivery at term and four subsequent spontaneous abortions at 12 to 16 weeks. The patient underwent desensitization utilizing graduated intravenous doses of penicillin followed by treatment with a constant infusion for eight days. She experienced no serious allergic reactions requiring alteration of therapy. We conclude that antibiotic desensitization may be a safe alternative during pregnancy if performed with careful monitoring. In this case, it allowed use of penicillin rather than less desirable alternatives.