Fingernail Onychomycosis Due to Aspergillus niger

Atypical and Unpredictable Superficial Mycosis Presentations: A Narrative Review

While typically exhibiting characteristic features, fungal infections can sometimes present in an unusual context, having improbable localization (eyelid, face, or joint); mimicking other skin diseases such as eczema, psoriasis, or mycosis fungoides; and appearing with unexpected color, shape, or distribution. The emergence of such a challenging clinical picture is attributed to the complex interplay of host characteristics (hygiene and aging population), environment (climate change), advances in medical procedures, and agent factors (fungal resistance and species emergence). We aim to provide a better understanding of unusual epidemiological contexts and atypical manifestations of fungal superficial diseases, knowing that there is no pre-established clinical guide for these conditions. Thus, a literature examination was performed to provide a comprehensive analysis on rare and atypical superficial mycosis as well as an update on certain fungal clinical manifestations and their significance. The research and standard data extraction were performed using PubMed, Medline, Scopus, and EMBASE databases, and a total of 222 articles were identified. This review covers published research findings for the past six months.

A 5-year single-center study about onychomycosis with a focus on Aspergillus spp. in Albania

BACKGROUND

Onychomycosis is a common nail infection caused by dermatophytes, nondermatophytes molds (NDM), and yeasts. The prevalence of Aspergillus spp. is increasing worldwide. This study aims to describe the epidemiological and microbiological features of onychomycosis, especially for Aspergillus spp.

METHODS

This is a 5-year retrospective study of clinically suspected onychomycosis in one microbiological clinic in Albania. The mycological examination, which included direct microscopic examination of nail scrapings with 20% KOH and culture, was performed on 411 patients. After incubation, we studied the macroscopic characteristics of the colonies, size, shape, and color, and their microscopic examination. We evaluated positive cases for Aspergillus, all cases where Aspergillus was grown in the culture, the microscopy was positive, and the culture was negative for dermatophyte.

RESULTS

Onychomycosis resulted positive in 267 patients (52.9% females vs. 47.1% males). A total of 62.2% resulted infected by dermatophytes, 29.6% by yeasts, and 8.2% by NDM. Onychomycosis resulted more frequent in the age group 15-64 years old (63%). Aspergillus spp. were found in 19 patients from 22 patients with NDM onychomycosis. Males (11 patients) and the age group 15-64 years old (14 patients) were more vulnerable to Aspergillus spp. A. niger, A. flavus, and A. terreus isolated from the nail cultures in our study. The culture resulted more superior to KOH examinations.

CONCLUSIONS

Our study indicates that NDM, including Aspergillus spp., are still rare findings from fungal examinations. However, dermatologist's clinical suspicion and microbiologist's skills are mandatory in diagnosing and properly managing patients with Aspergillus spp.

Aspergillus Genus and Its Various Human Superficial and Cutaneous Features

Superficial and cutaneous aspergillosis is a rare fungal disease that is restricted to the outer layers of the skin, nails, and the outer auditory canal, infrequently invading the deeper tissue and viscera, particularly in immunocompromised patients. These mycoses are acquired through two main routes: direct traumatic inoculation or inhalation of airborne fungal spores into paranasal sinuses and lungs. Lesions are classified into three categories: otomycosis, onychomycosis, and cutaneous aspergillosis. Superficial and cutaneous aspergillosis occurs less frequently and therefore remains poorly characterized; it usually involves sites of superficial trauma-namely, at or near intravenous entry catheter site, at the point of traumatic inoculation (orthopaedic inoculation, ear-self-cleaning, schizophrenic ear self-injuries), at surgery incision, and at the site of contact with occlusive dressings, especially in burn patients. Onychomycosis and otomycosis are more seen in immunocompetent patients, while cutaneous aspergillosis is widely described among the immunocompromised individuals. This paper is a review of related literature.

Pestalotioid fungi: A rare agent of onychomycosis among agriculture workers

Background and Purpose:

Pestalotioid fungi are ubiquitous environmental molds that have received considerable attention in recent times not only because of their role as a plant pathogen but also owing to their high frequency of retrieval from human diseases. Regarding this, the present study was conducted to investigate onychomycosis caused by pestalotioid fungi, commonly considered important phytopathogens causing grey blight disease in Camellia sinensis.

Materials and Methods:

A total of 122 agriculture workers were enrolled from Assam, India. Direct microscopic examination was carried out using 40% KOH to determine the presence of any fungal element. Further processing of the specimens for the isolation of fungi was performed using the standard protocol. In addition, the keratinolytic potential of the isolates was evaluated by means of the in vitro hair perforation test.

Results:

Out of 103 culture-positive samples, non-dermatophyte and dermatophyte molds constituted 82.52% (n=85) and 6.79% (n=7) of the samples, followed by yeasts (n=1, 0.9%) and sterile hyphae (n=10, 9.7%). With regard to the isolated non-dermatophyte molds (82.69%), 4 cases belonged to pestalotioid fungi, such as Neopestalotiopsis piceana (n=1), Pestalotiopsis species (n=1), and Pseudopestalotiopsis theae (n=2). The keratinolytic activity of Pestalotiopsis species showed perforation by disrupting the hair cortex; furthermore, macroconidia were found to be present inside the human hair.

Conclusion:

A high rate of NDM isolation may be attributed to constant exposure to adverse environmental and occupational hazards. This study highlighted the importance of “pestalotioid fungi” as the rare etiologic agent of onychomycosis. Another remarkable finding was the keratinolytic potential of Pestalotiopsis species, which is unique in this study.

Fungal infections of the feet in patients with erysipelas of the lower limb: is it a significant clinical problem?

BACKGROUND

Erysipelas is a bacterial infection of the superficial layers of the skin usually caused by Group A Streptococci, often seen in clinical practice. Fungal infections of the feet and elderly age are some of the most significant risk factors for the infection. The aim of the study was to evaluate the frequency of fungal infections from different regions of the feet in patients with erysipelas.

METHODS

56 patients with clinically diagnosed erysipelas and 56 healthy individuals were clinically examined and tested for fungal infection in three locations: toenails, interdigital space, and soles. The collected samples were evaluated under a microscope and then mycological cultures on Sabouraud's medium were prepared. After 4 weeks of incubation, the cultures were analysed with the identification of particular pathogens.

RESULTS

42.9% (24/56) of the patients with erysipelas had positive mycological cultures. Toenails and interdigital spaces (both 62.5%) were the most frequently affected areas, followed by soles (37.5%). The most common pathogen was T. rubrum (43.18%), followed by Candida spp. (27.27%), and T. mentagrophytes var.interdigitale (13.63%). Only 14.3% (8/56) of the samples taken from the control group were positive and T.rubrum was the only type of fungus cultured.

CONCLUSIONS

Fungal infections of the feet are important risk factors for the first episode as well as recurrent erysipelas. Prevention and early treatment of fungal infections, especially in elderly people, can significantly reduce the incidence of erysipelas.

Onychomycosis Associated with Superficial Skin Infection Due to Aspergillus sydowii in an Immunocompromised Patient

Opportunistic fungal infections of the skin and nail are frequently encountered in human. Recent years have shown increased incidence of fungal infections especially in immunocompromised patients. Onychomycosis in HIV-infected patients is reported to occur in 15-40%, four times more than in the general population. Here, we report a case of fingernail proximal subungual onychomycosis with associated skin infection caused by an opportunistic mold, Aspergillus sydowii, in a HIV positive individual. Isolation of A. sydowii from nail and skin of an immunocompromised person needs accurate identification for successful treatment.

Subungual onychomycosis due to Aspergillus niger mimicking a glomus tumor: A case report

Onychomycosis is a common nail infection caused by dermatophytes, while non-dermatophytes including Aspergillus spp. are causes of nail onychomycosis. Aspergillus niger is not common as a cause of nail onychomycosis. In the current study we present a 60-year-old woman with subungual onychomycosis due to Aspergillus niger mimicking a glomus tumor. Physical examination revealed right thumb had a black color of nail bed. Localized tenderness and severe pain were observed. However, the cold sensitivity test, Loves pin test and Hildreths test were negative. On radiograph, bone erosion was found in a part of distal phalanx at the right thumb. Magnetic resonance imaging identified a mass at the subungual space, which exhibited low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The differential diagnosis included glomus tumor and infection. The histological findings demonstrated dichotomous septate hyphae. The culture was positive for Aspergillus niger. The results suggested that when physical examination is not typical for a glomus tumor, other diseases may be considered. Additionally, frozen section diagnosis may be useful.

Incidence and biodiversity of yeasts, dermatophytes and non-dermatophytes in superficial skin infections in Assiut, Egypt

OBJECTIVE

The aim was to identify the incidence of the causal agents from dermatophytes, non-dermatophytes and yeasts in Assiut Governorate employing, beside the morphological and physiological techniques, the genotypic ones.

PATIENTS

Samples from infected nails, skin and hair were taken from 125 patients.

MATERIALS AND METHODS

Patients who presented with onychomycosis, tinea capitis, tinea corporis, tinea cruris and tinea pedis during the period from February 2012 to October 2015 were clinically examined and diagnosed by dermatologists and were guided to Assiut University Mycological Centre for direct microscopic examination, culturing and identification.

RESULTS

Onychomycosis was the most common infecting (64.8% of the cases) followed by tinea capitis (17.6%). Direct microscopic preparations showed only 45 positive cases, while 96 cases showed positive cultures. Infections were more frequent in females than males. Fifty-one fungal species and 1 variety were obtained. Yeasts were the main agents being cultured from 46.02% of total cases. Non-dermatophytes were the second etiologic agents. Aspergillus was responsible for infecting 19.47% of total cases and dermatophytes appeared in only 15.93% of the cases.

CONCLUSIONS

Yeasts were the main causal agents followed by non-dermatophytic fungi (mainly species of Aspergillus, then Alternaria, Scopulariopsis and Fusarium). Both direct microscopic preparations and culturing are recommended for mycological evaluation of clinical specimens. Sequence analysis of ITS region is recommended for yeast identification.

Mycology - an update Part 3: Dermatomycoses: topical and systemic therapy

Treatment of dermatophyte infections is based on the clinical picture and mycological detection of the causative pathogen. Based on the appropriate indication, onychomycosis can be treated topically using an antimycotic nail lacquer. Atraumatic nail abrasion with 40 % urea ointment has a beneficial effect on healing. Continuous treatment of onychomycosis with terbinafine represents the most effective systemic therapy. Terbinafine or itraconazole are the safest and most effective antimycotic agents for the treatment of onychomycosis in children. For laser therapy of onychomycosis, only a few studies on clinical efficacy are available. Regarding tinea capitis, targeted species-specific therapy of dermatophytosis of the scalp is currently recommended. Terbinafine, yet also itraconazole and fluconazole, are effective in tinea capitis caused by Trichophyton species. Microsporum infections of the scalp are preferably treated with griseofulvin, alternatively with itraconazole or fluconazole. Terbinafine is less effective. Candidal intertrigo are topically treated with nystatin, but azoles or ciclopirox olamine are also suitable candidates. Systemically, fluconazole or itraconazole are used. Topical and systemic antimycotics are equivalent forms of therapy in acute vulvovaginal mycosis. Fluconazole is the drug of choice in chronic recurrent vulvovaginal mycosis caused by Candida albicans. Ketoconazole shows very good efficacy in tinea versicolor. With respect to systemic treatment of severe and widespread tinea versicolor, itraconazole is the drug of choice.

Aspergillus species as emerging causative agents of onychomycosis

BACKGROUND

Onychomycosis is a common nail infection caused by dermatophytes, non-dermatophyte molds (NDM), and yeasts. Aspergillus species are emerging as increasing causes of toenail onychomycosis. The purpose of this study was species delineation of Aspergillus spp. isolated from patients with onychomycosis.

METHODS

During a period of one year (2012-2013), nail samples were collected from patients clinically suspected of onychomycosis and subjected to microscopic examination and culture. Species identification was performed based on macro- and micro-morphology of colonies. For precise species identification, PCR-amplification and sequencing of the beta-tubulin gene followed by BLAST queries were performed where required.

RESULTS

A total of 463/2,292 (20.2%) tested nails were diagnosed with onychomycosis. Among the positive specimens, 154 cases (33.2%) were identified as saprophytic NDM onychomycosis, 135 (29.2%) of which were attributable to Aspergillus. Aspergillus species isolated from the infected nails included Aspergillus flavus (77.3%, n=119), Aspergillus niger (n=4), Aspergillus tubingensis (n=4), Aspergillus terreus (n=3), Aspergillus sydowii (n=2), Aspergillus spp. (n=2), and Aspergillus candidus (n=1). Among the patients diagnosed with onychomycosis due to Aspergillus (average patient age, 47.4 years), 40 had fingernail and 95 toenail involvement. The large toenails were most commonly affected.

CONCLUSIONS

This study identified a markedly high occurrence of A. flavus, and this fungus appears to be an emerging cause of saprophytic onychomycosis in Iran. The study moreover highlights the necessity of differentiating between dermatophytic and non-dermatophytic nail infections for informed decisions on appropriate therapy.