# Phaeohyphomycosis: A 10-Year Study From a Tertiary Care Centre in South India

## TL;DR

This 10-year study from South India examines the epidemiology and clinical features of phaeohyphomycosis, a fungal infection, highlighting its underrepresentation and diagnostic challenges.

## Contribution

The study provides new epidemiological data on phaeohyphomycosis from a South Indian tertiary care center over a decade.

## Key findings

- 46 cases of phaeohyphomycosis were identified, with lesions mostly on extremities and a 17% history of thorn pricks.
- Alternaria was the most commonly isolated pathogen in cultured cases, accounting for 42% of isolates.
- The study emphasizes the importance of histopathological examination for accurate diagnosis due to the infection's varied and often subtle clinical presentation.

## Abstract

Background

Phaeohyphomycosis, a fungal infection caused by dematiaceous fungi, presents a significant health challenge affecting both immunocompromised and immunocompetent individuals. Despite its clinical importance, phaeohyphomycosis remains underrepresented in epidemiological studies, leading to gaps in our understanding of its prevalence, clinical manifestations, and associated risk factors. This retrospective study conducted in South India aims to address these gaps by examining the incidence, diverse clinical presentations, and other relevant epidemiological aspects of phaeohyphomycosis in patients referred for pathological examination.

Objective

To investigate the epidemiological trends, clinicopathological characteristics, and microbiological spectrum of phaeohyphomycosis in patients at a tertiary care center in South India over 10 years.

Materials and methods

This comprehensive study was conducted at Employees State Insurance Corporation Medical College & Post Graduate Institute of Medical Sciences and Research (ESIC Medical College and PGIMSR), Chennai, embodying a retrospective observational approach. Over a decade, researchers meticulously reviewed cases diagnosed with phaeohyphomycosis. This involved an in-depth analysis of patients' medical records to gather detailed information on presenting symptoms, history of thorn pricks, diabetic status, and other pertinent epidemiological data. Additionally, culture samples were selectively obtained from patients exhibiting abscesses or cystic swellings, followed by a thorough assessment of the culture reports.

Results

In the ten-year study period, a total of 46 cases were identified. Most lesions were solid or cystic and located on extremities, predominantly affecting the digits. Eight cases (17%) had a history of thorn prick injuries, and six cases (13%) were associated with diabetes mellitus. Microscopic examination revealed necrosis, granulomas, varying degrees of inflammatory infiltrates, giant cells, and pigmented fungal hyphae. In some cases, biopsies revealed pseudoepitheliomatous hyperplasia. Among the 19 cases where culture was performed, Alternaria was the most commonly isolated pathogen (42%).

Conclusion

The study brings to light the diagnostic challenges inherent in phaeohyphomycosis cases, which often eluded clinical diagnosis and were only conclusively identified via pathological examinations. While this research was primarily focused on outpatients presenting with minor symptoms, it underscores the potential for more severe clinical presentations in immunocompromised patients. Our findings emphasize the need for increased clinical awareness and the pivotal role of histopathological examination in accurately diagnosing phaeohyphomycosis, particularly in cases with extremity lesions. This study contributes significantly to the understanding of phaeohyphomycosis and advocates for ongoing research to better understand its epidemiology and clinical diversity.