Cutaneous manifestations of deep mycoses in Nigeria: a systematic review

Background Deep mycoses are serious fungal diseases commonly associated with the immunocompromised but can also present in the immunocompetent following severe exposure to fungal pathogens. Included in this group are subcutaneous and systemic fungal infections. Objectives Reviews highlighting skin involvement in patients with deep mycosis in the Nigerian setting are sparse in the literature. This systematic review summarized the clinical presentation, risk factors, and diagnosis of deep mycosis presenting with cutaneous manifestations in Nigerians. Design This was a systematic review conducted following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. Data sources and methods PubMed, Google Scholar, and the African Journal Online database were searched from inception to February 2024 to identify published articles from Nigeria on deep mycoses with cutaneous manifestations. We included single case reports and case series on cutaneous involvement in deep fungal infections in Nigeria. Review articles, guidelines, meta-analyses, animal studies, and fungal studies not relating to the Nigerian setting were excluded. Results We identified 16 well-documented articles on deep cutaneous mycoses published in Nigeria over the past six decades which amounted to 137 cases; 102 (74.5%) cases were reported before the year 2000, while the remainder were published within the past two decades. The 137 cases were majorly histoplasmosis ( n = 87, 63.5%) and eumycetoma ( n = 19, 13.9%) and predominant risk factors, farming ( n = 13, 9.5%) and diabetes mellitus ( n = 3, 2.2%), The diagnosis of cases was predominantly via histopathology ( n =131, 95.6%) with a few cases diagnosed by fungal culture ( n = 15, 10.9%), and antigen assay ( n = 1, 0.7%) respectively. Twenty-one (15.3%) were clinically diagnosed as cancers including a case of carcinoma of the skin, and one each (0.7%) as skin tuberculosis or neurofibromatosis but all histologically confirmed as deep cutaneous mycoses. Conclusion The decline of reports on deep cutaneous mycoses in recent times suggests neglect or a low index of suspicion from attending clinicians. This is further buttressed in the misdiagnosis of cases as other clinical entities. Ensuring a histological diagnosis of skin lesions, especially in at-risk patients will mitigate these gaps.