First record of Aspergillus brunneus causing fingernail aspergillomycosis in a primary schoolchild

Anjali Sharma; Geeta Sumbali

doi:10.4103/ijpd.ijpd_150_21

CASE REPORT

Year : 2022 | Volume : 23 | Issue : 2 | Page : 153-155

First record of Aspergillus brunneus causing fingernail aspergillomycosis in a primary schoolchild

Anjali Sharma, Geeta Sumbali
Department of Botany, University of Jammu, Jammu and Kashmir, India

Date of Submission	30-Oct-2021
Date of Decision	19-Jan-2022
Date of Acceptance	20-Jan-2022
Date of Web Publication	30-Mar-2022

Correspondence Address:
Dr. Anjali Sharma
Department of Botany, University of Jammu, Jammu, Jammu and Kashmir
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/ijpd.ijpd_150_21

Abstract

Onychomycosis among children has been reported to be of less common occurrence than in adults. However, species of Aspergillus are emerging as the new causative agents of onychomycosis. Here, we report a new case of fingernail aspergillomycosis in an 11-year-old schoolboy. The thumbnail of the patient demonstrated thickening, yellow discoloration, and onycholysis at the distal end. Culturing of the clinical nail sample on Sabouraud dextrose agar medium supplemented with chloramphenicol (0.05 mg/ml) produced yellowish-white colonies repeatedly on more than three consecutive occasions. Slide cultures showed uniseriate phialides covering two-third of the vesicle. Further, DNA sequencing of the internal transcribed spacer region confirmed its identity as Aspergillus brunneus. This is the first documented report of A. brunneus as an etiological agent of onychomycosis.

Keywords: Aspergillomycosis, Aspergillus brunneus, fingernail, onychomycosis

How to cite this article:
Sharma A, Sumbali G. First record of Aspergillus brunneus causing fingernail aspergillomycosis in a primary schoolchild. Indian J Paediatr Dermatol 2022;23:153-5

How to cite this URL:
Sharma A, Sumbali G. First record of Aspergillus brunneus causing fingernail aspergillomycosis in a primary schoolchild. Indian J Paediatr Dermatol [serial online] 2022 [cited 2022 May 17];23:153-5. Available from: https://www.ijpd.in/text.asp?2022/23/2/153/341462

Introduction

Aspergillomycosis is generally used to describe mycosis caused by Aspergillus species. A variety of human diseases are known to be caused by Aspergillus species, of which onychomycosis is of worldwide occurrence. According to published reports on the epidemiology of onychomycosis due to Aspergillus species, it has been shown that they constitute 7.7%–100% of the nondermatophytic onychomycosis in general population.^[1]

However, cases of onychomycosis among children are comparatively less common than in adults, but their frequency is on the rise.^[2],[3] Further, the prevalence of onychomycosis is much lower in children between 0 and 18 years of age, which may be due to their faster nail growth, smaller nail surface, lower prevalence of tinea pedis, and reduced exposure to fungi.^[2] The prevalence of onychomycosis among children has been reported to range from 0.2% to 2.6%.^[4] According to some reports, male children are more likely affected with onychomycosis than female children.^[2]

In this communication, we report a new case of fingernail aspergillomycosis detected in a schoolboy of district Rajouri (UT of Jammu and Kashmir).

Case Report

We report a case of onychomycosis of the thumbnail of the left hand in an 11-year-old schoolboy residing at Darhal, Rajouri district (J&K). He complained of progressive discoloration of the nail with mild pain for the past 6 months. Examination revealed a thickened nail with yellowish-brown discoloration of the complete nail plate with the presence of subungual hyperkeratosis [Figure 1]a. The proximal and the lateral nail folds with cuticle were normal. There was no history of any antecedent trauma or any other immunocompromised state. The rest of the general and clinical examination of the patient was normal. There was no significant past or family history. After taking proper consent and history of the patient, dystrophied nail clippings/scrapings were taken for the mycological examination (cultural and microscopic details) and later molecular characterization was done to confirm the identity of the nail pathogen. The sampled dystrophied nail clippings were cleaned with 70% ethanol, cultured on Sabouraud dextrose agar medium supplemented with chloramphenicol (0.05 mg/ml), and incubated at 28°C for up to 14 days. Repeated isolations on more than three consecutive occasions yielded a species of Aspergillus whose mycological and molecular identification was confirmed as Aspergillus brunneus Delacroix.

Figure 1: (a) Left-hand thumbnail showing yellowish-brown discoloration with the presence of onycholysis with subungual hyperkeratosis. (b) Colonies of Aspergillus brunneus on Czapek's yeast agar medium after 7 days of growth at 28°C. (c) Lactophenol cotton blue mount of Aspergillus brunneus showing uniseriate heads covering over two-third of the vesicle. (d) Variably shaped conidia in chains: globose to subglobose, tuberculate, and rough walled (Bars = 10 μm)

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Colonies on Czapek's yeast agar medium were moderately deep, plane, margins entire, mycelium sulfur yellow, texture floccose, sporulation sparse; conidia en masse pale green, soluble pigments absent; exudates absent, reverse fulvous. Conidiophores with smooth stipes, hyaline or light brown, 700–1200 × 7–18 μm. Vesicles globose to subglobose, 32–58 μm wide, fertile over two-third of the entire surface. Phialides flask shaped 10–18.5 × 7–12.5 μm. Conidia globose to subglobose, tuberculate, 8–15 × 8–13 μm [Figure 1]b, [Figure 1]b, [Figure 1]c, [Figure 1]d.

Ribosomal ribonucleic acid gene sequencing was done for the molecular identification. The internal transcribed spacer sequences obtained were aligned using BLAST tool against the National Center for Biotechnology Information (NCBI) nucleotide database (http://blast.ncbi.nlm.nih.gov/) for most homologous sequences. The percentage similarity of the pathogenic fungi using NCBI-BLASTn tool was above 99%. The fungal pathogen was identified as A. brunneus (Accession No. MT337603.1). The strain number given to this pathogen is AP-I. Sequences of the identity >90% were retrieved and aligned with the sequence of AP-I, using Clustal W module of Mega-X software. The evolutionary history was inferred by using the neighbor-joining method to obtain the phylogenetic tree. The tree authentication was designated in terms of bootstrap P values (above 50%) given at branch nodes. The fungus Corynespora cassiicola from the class Dothideomycetes was used as an outgroup [Figure 2].

Figure 2: Neighbor-joining tree of AP-I strain based on internal transcribed spacer sequences. Confidence values (above 50%) obtained from a 500-replicate bootstrap analysis are shown at branch nodes. Corynespora cassiicola was used as an outgroup

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Discussion

Aspergillus species are ubiquitous environmental molds found in the air, soil, water, and decaying vegetation. Onychomycosis due to Aspergillus species usually causes distal lateral subungual onychomycosis, and the toenails are 25 times more frequently involved than the fingernails because of increased exposure to soil, decaying vegetation, water, etc., where this mold frequently thrives.^[5] Further, it has also been shown that among the people with fingernail and toenail aspergillomycosis, 85% had discolored nails, 89% were with brittle nails, and 93% were with hard nails and hyperkeratosis.^[6]

Aspergillus onychomycosis has been observed more among individuals with occupational exposures.^[5] According to Moore and Weiss,^[7] Aspergillus infection starts underneath the nail near the hyponychium region where the spores get lodged or at the lateral nail folds and the diseased nail plate gets colonized. Although Aspergillus onychomycosis is uncommon in children,^[2] Aspergillus niger has been isolated from a 3-year-old immunocompetent child with single nail mycosis.^[8] Recently, Aspergillus species has also been reported in a neonate by Verma et al.^[9] Onychomycosis in children between 0 and 18 years of age has also been reported by Kim et al.^[10] who found concomitant tinea pedis infection and distal and lateral subungual onychomycosis to be the most common clinical type. As most of the children are careless about cleanliness of hands and feet, they may acquire fungal infections during sports activity, which may lead to nail trauma, or they may get infected through the contaminated environment.

In the present investigation, A. brunneus is being reported as a new case of fingernail aspergillomycosis. Earlier, A. niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus versicolor, Aspergillus sydowii, and Aspergillus persii have been reported as causal agents of onychomycosis among schoolchildren of other two districts (Jammu and Doda) of the union territory of Jammu and Kashmir. So far, there is no documented report of A. brunneus as an etiological agent of onychomycosis and can be considered as a new addition to the list of aspergilli causing onychomycosis. The study implicates that there is a need for careful mycological examination of children diagnosed with nail dystrophies.

Declaration of consent

The authors certify that they have obtained all appropriate consent forms, duly signed by the parent(s) of the patient. In the form the parent(s) has/have given his/her/their consent for the images and other clinical information of their child to be reported in the journal. The parents understand that the names and initials of their child will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Acknowledgments

The authors are thankful to the Head, Department of Botany, University of Jammu (India), for providing laboratory facilities and to the University Grants Commission (UGC), Special Assistance Programme (SAP-II), New Delhi (India), for providing financial assistance during the period of research.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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