Deep mycoses and pseudomycoses of the foot: a single-center retrospective study of 160 cases, in a tertiary-care center in Mexico.

BACKGROUND

Deep mycoses and pseudomycoses (DMP) may cause significant disability and even death; however, the reports regarding these diseases, mainly affecting the foot, are scarce.

OBJECTIVE

To describe the epidemiological, clinical, and diagnostic characteristics of DMP of the foot in 160 patients.

METHODS

A retrospective and observational study of DMP affecting the foot was carried out in a tertiary-care center in Mexico for 20 years (from January 2000 to December 2019). Cases with confirmatory microbiological studies were included; the identification of the isolated fungi was based on the forms of reproduction. For actinomycetes, morphological analysis in an automated system ATB Vitek® 1574 (Biomèrieux) was used. The fungi were identified by PCR, using several primers from the ITS regions and for actinomycetes in the 16S rRNA region. Data from histopathological studies were also collected.

RESULTS

One hundred and sixty proven cases of DMP of the foot were included. The cases were categorized into nine types of infections including mycetoma (actinomycetoma and eumycetoma) in 102 cases (63.7%); sporotrichosis in 21 cases (13.1%); chromoblastomycosis, 18 cases (11.2%); phaeohyphomycosis, 3 cases (1.8%); histoplasmosis, 12 cases (7.5%); coccidioidomycosis 2 cases (1.2%) and botryomycosis and nocardiosis with one case respectively (0.6%). Most cases developed after traumatic implantation (147 cases, 91.8%). One hundred fifteen cases (71.8%) were men. The evolution was chronic in 125 cases (78.2%); bone involvement was observed in 64 cases (40%). Parasitic forms were observed In 139 cases (86.8%). The isolation and identification of the etiological agents were confirmed in all cases.

CONCLUSION

The main DMP affecting the foot were infections due to traumatic implantation; most were endemic mycoses. The clinical characteristics and the evolution of the diseases are easily misdiagnosed, and thus, diagnostic tests are usually required.