What severe systemic allergic reactions can chlorhexidine in Nystaform HC Ointment cause?

Chlorhexidine in Nystaform HC Ointment can cause generalised allergic reactions and anaphylactic shock; hypersensitivity prevalence is unknown but likely very rare, and the ointment should not be given to anyone with a potential history of allergy to a chlorhexidine-containing compound.