Antibiotic produced by Streptomyces venezuelae. It comprises a nitrobenzene ring linked to propanol, with an amide group binding to a derivative of dichloroacetamide acid.
Allergy to penicillin.
Previous exposure to phenicols.
Topical use of chloramphenicol may lead to: contact dermatitis, anaphylactic shock, aplastic anemia.
General: anaphylactic shock, fever.
Cutaneous: urticaria, maculopapular rash, angioedema, contact dermatitis.
Haematological: aplastic anemia.
Positive scratch and patch test reported in some cases involving cutaneous manifestations (patch-tests with chloramphenicol 1% in pet).
Antibodies against chloramphenicol have been found, with no obvious clinical manifestation.
The dichloroacetamide ring is probably the major antigenic determinant.
Cross-sensitivity between chloramphenicol and synthetic derivatives is likely.