Proximal Subungual Onychomycosis in the Immunocompetent: A Case Report and Review of the Literature

April 2018 | Volume 17 | Issue 4 | Case Reports | 475 | Copyright © April 2018

Sydney E. Liang BS,a David E. Cohen MD MPH,b and Evan A. Rieder MDb

aNew York University School of Medicine, New York, NY bThe Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY

Table1but further investigation has identified them as a noteworthy cause of PSO.5,6 Our patient, although fungal culture was not obtained, demonstrated mild erythema and paronychia of his affected digits, suggesting his PSO may have been caused by a NDM. This would support the growing evidence demonstrating that NDMs can be an important cause of PSO in immunocompetent individuals.PSO is an uncommon disease that is most frequently found in immunocompromised patients. Dermatophytes are the most common cause, while NDMs can also provoke the disease. This case of PSO highlights the potential for its rare occurrence in a healthy host. However, the clinical presentation of PSO should always trigger an evaluation for possible immunodeficiency illnesses.


The authors have no relevant conflicts of interest to disclose. The authors do not have grants or additional technical support to disclose. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. This manuscript is not under consideration elsewhere and has not been previously published.


  1. Hay RJ, Baran R. Onychomycosis: a proposed revision of the clinical classification. J Am Acad Dermatol. 2011;65(6):1219-1227.
  2. Gupta AK, Taborda P, Taborda V, et al. Epidemiology and prevalence of onychomycosis in HIV-positive individuals. Int J Dermatol. 2000;39(10):746-753.
  3. Elewski BE. Clinical pearl: proximal white subungual onychomycosis in AIDS. J Am Acad Dermatol. 1993;29(4):631-632.
  4. Rongioletti F, Persi A, Tripodi S, Rebora A. Proximal white subungual onychomycosis: a sign of immunodeficiency. J Am Acad Dermatol. 1994;30(1):129-130.
  5. Tosti A, Piraccini BM, Lorenzi S. Onychomycosis caused by nondermatophytic molds: clinical features and response to treatment of 59 cases. J Am Acad Dermatol. 2000;42(2 Pt 1):217-224.
  6. Elewski BE. Onychomycosis: pathogenesis, diagnosis, and management. Clin Microbiol Rev. 1998;11(3):415-429.
  7. Weinberg JM, Koestenblatt EK, Don PC, White SM, Stein MN, Bamji M. Proximal white subungual onychomycosis in the immunocompetent patient: report of two cases and review of the literature. Acta Derm Venereol. 1999;79(1):81-82.
  8. Piraccini BM, Morelli R, Stinchi C, Tosti A. Proximal subungual onychomycosis due to Microsporum canis. Br J Dermatol. 1996;134(1):175-177.
  9. Baran R, Tosti A, Piraccini BM. Uncommon clinical patterns of Fusarium nail infection: report of three cases. Br J Dermatol. 1997;136(3):424-427.
  10. Schmidt BM, Holmes, C. Proximal White Onychomycosis in an Immunocompetent Patient: A Case Report. Case Reports in Clinical Medicine. 2015;4:4.


Evan A. Rieder MD