Onychomycosis and Immunodepression

Onychomycosis in immunocompromised population: Phenotypic and molecular identification

Onychomycosis is common among immunosuppressed individuals. Renal transplant recipients (RTR) and lupus nephritis (LN) patients are submitted to corticosteroid and other immunosuppressive therapy; and diabetes mellitus (DM) patients are intrinsically immunocompromised.

OBJECTIVES

The aim of this study was to characterise and identify fungal infections on the nails (feet and hands) in immunocompromised patients.

METHODS

The clinical material, nail scales (foot and/or hand), was collected from 47 RTR, 66 LN, 67 DM, and 78 immunocompetent individuals (control group). Phenotypic and molecular analyses were performed.

RESULTS

A total of 258 patients were examined. There was a female predominance, except in the RTR. The average age was 52 years old. Lateral distal subungual onychomycosis (OSDL) (75.2%), mainly affecting the hallux nail, was frequent. The predominance of dermatophyte on toenails and Candida species on fingernails was statistically significant. A higher frequency of fingernail involvement in LN and DM, and for LN, the difference was significant (p = .0456). Infections by Candida spp. were more frequent in DM. Using molecular methods, 87.2% of diagnoses were confirmed, identifying fungal agents at the species level. Dermatophytes, Trichophyton rubrum and Trichophyton interdigitale and the species of Candida, C. parapsilosis and C. albicans, were the most frequent fungal agents.

CONCLUSIONS

Molecular techniques (sequencing of ITS regions of rDNA) offer greater accuracy, although there is no difference, regarding the detection. Clinical presentation and fungal species may differ somewhat from the general population. Immunosuppression did not increase fungal detection positivity.

Nail dermatophytoma in HIV-infected patients in Cali, Colombia

INTRODUCTION

A dermatophytoma is a mass of hyphae that is observed at direct examination, it responds poorly to treatment with antifungal drugs, some authors have proposed that it is actually a biofilm. This pathology is underdiagnosed, and its true incidence is unknown.

OBJECTIVES

This study presents the clinical findings of dermatophytoma in HIV/AIDS patients from Colombia presenting onychomycosis.

MATERIAL AND METHODS

A transversal observational descriptive study was carried out in a third level university hospital. One hundred thirty HIV positive patients diagnosed using ELISA and Western Blot that presented nail lesions on their hands and/or feet compatible with onychomycosis were included. Samples taken from affected nails were observed in direct examination with KOH and seeded onto Sabouraud agar, mycosel agar and dextrose-potato agar. Molds were identified based on macroscopic and microscopic characteristics.

RESULTS

Six (4.6%) individuals presented dermatophytoma. Average age was 43 years (range 33-50); nails more commonly affected (5/6) were on the toes, principally the hallux. Clinical manifestations included a yellow or white, rounded or linear dense area on the nail. Superficial white onychomycosis was present in 83.3% of the patients. Fungal cultures were obtained in only 5 patients; Trichophyton mentagrophytes complex was found in 2 individuals while T. rubrum, T. tonsurans and Epidermophyton floccosum were in the other 3. Average cell count for CD4⁺T lymphocytes was 86.8 cells/mm³ (range 9-282).

CONCLUSIONS

This is the first report in Colombia of dermatophytoma in HIV/AIDS patients, most of them had a CD4+ T lymphocytes count less than 200 cells/mm3. Several clinical forms of onychomycosis were observed, the most frequent was the white superficial onychomycosis.

Subclinical Onychomycosis: Not Present in HIV-Positive Population?

Background

Onychomycosis is one of the most common nail diseases and constitutes up to 50% of all nail conditions. It is a chronic fungal nail infection common in the HIV-infected population. Few studies have found fungal organisms in the nail without clinical evidence, and thus, termed subclinical onychomycosis.

Objectives

We analyzed the nails of the HIV population in our hospital, searching for subclinical onychomycosis.

Method

A distal nail clipping was stained with PAS and observed by a trained dermatopathologist.

Results

All of our samples (n = 48) turned out to be negative for fungal structures.

Conclusions

The epidemiology of onychomycosis is changing, treatment options are much better now, and diagnosis and infection detection are being done earlier. Therefore, we will continue to further study this disease in other patient populations so that we can compare our results and see whether the incidence of onychomycosis in the HIV population is now similar to that in those without HIV infection of the same age.