• No cases reported in Ireland (to March 2023)
  • Increasing number of cases in migrants to the EU
  • Beware in unvaccinated or immunocompromised
  • Most present with cutaneous form

Cutaneous Diphtheria


  • Blueish/grey eschar with raised edges
  • Consider in chronic/unhealing wounds
  • C. diphtheriae may co-contaminate wounds growing Staph. or Strep.

Respiratory Diphtheria


  • Sore throat, fever
  • ± Adherent greyish membrane (bleeds when manipulated) of the tonsils
Image from PHIL-ID1942
Diphtheria membrane
Diphtheria membrane from wikimedia

Differential Dx

  • Strep. / viral pharyngitis
  • Vincent's angina (bact. gingivitis ± Borrelia vincentii)
  • Infectious mononucleosis
  • Oral syphilis
  • Candidiasis


  • Dacron or Viscose swab before starting antibiotics
  • Skin, nose and throat
  • Culture a section of membrane if possible


  • Contact micro. in all suspected
  • Advise restrict contact with other until swap results
  • Contact Department of Public Health immediately

Content by Dr Íomhar O' Sullivan. Last review Dr ÍOS 26/04/23.