Opportunistic infection during treatment with low dose methotrexate

Am J Respir Crit Care Med. 1994 Jul;150(1):258-60. doi: 10.1164/ajrccm.150.1.8025760.


Two patients receiving low dose methotrexate, one with rheumatoid arthritis and the other with pityriasis rubra pilaris, developed disseminated histoplasmosis and Mycobacterium avium intracellulare pneumonia, respectively. Twenty-three cases of opportunistic infection in patients receiving low dose methotrexate have been reported previously, with Pneumocystis carinii pneumonia being the most common infection (10 of 23, 43%). Patients receiving low dose methotrexate are at risk for opportunistic infection despite normal leukocyte counts.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Aged
  • Female
  • Histoplasmosis / immunology
  • Humans
  • Immunosuppression Therapy
  • Male
  • Methotrexate / administration & dosage*
  • Methotrexate / adverse effects
  • Middle Aged
  • Mycobacterium avium-intracellulare Infection / immunology
  • Opportunistic Infections / immunology*


  • Methotrexate