Genetic risk factors for human susceptibility to infections of relevance in dermatology

Genetic Susceptibility to Fungal Infections and Links to Human Ancestry

Over the ages, fungi have associated with different parts of the human body and established symbiotic associations with their host. They are mostly commensal unless there are certain not so well-defined factors that trigger the conversion to a pathogenic state. Some of the factors that induce such transition can be dependent on the fungal species, environment, immunological status of the individual, and most importantly host genetics. In this review, we discuss the different aspects of how host genetics play a role in fungal infection since mutations in several genes make hosts susceptible to such infections. We evaluate how mutations modulate the key recognition between the pathogen associated molecular patterns (PAMP) and the host pattern recognition receptor (PRR) molecules. We discuss the polymorphisms in the genes of the immune system, the way it contributes toward some common fungal infections, and highlight how the immunological status of the host determines fungal recognition and cross-reactivity of some fungal antigens against human proteins that mimic them. We highlight the importance of single nucleotide polymorphisms (SNPs) that are associated with several of the receptor coding genes and discuss how it affects the signaling cascade post-infection, immune evasion, and autoimmune disorders. As part of personalized medicine, we need the application of next-generation techniques as a feasible option to incorporate an individual’s susceptibility toward invasive fungal infections based on predisposing factors. Finally, we discuss the importance of studying genomic ancestry and reveal how genetic differences between the human race are linked to variation in fungal disease susceptibility.

Differentiation of mucosal lesions in mucocutaneous leishmaniasis and paracoccidioidomycosis

Mucocutaneous leishmaniasis and paracoccidioidomycosis are infectious diseases with similar epidemiological and clinical aspects. Cases of both diseases may manifest similar lesions in the mucosa. Therefore, the determination of distinguishing characteristics for the purpose of differential diagnosis is critical for better management of the diseases. The present study evaluated factors that assist in the differentiation of mucosal lesions between these diseases. This cross-sectional study included data from medical records of 122 cases of mucocutaneous leishmaniasis and 83 cases of paracoccidioidomycosis attended at the university hospital Cassiano Antonio Moraes, located in Vitória, Espírito Santo State, Brazil. Comparison between the diseases included the following variables: sex, age, time of disease evolution, location of the lesion and symptoms. Adults and males were affected by both diseases at higher rates. Lesions in the nasal region (95.1%; p-value = 0.000) and the pharynx (20.5%; p-value = 0.009) and nasal obstruction (34.4%; p-value = 0.000) were associated with leishmaniasis. Paracoccidioidomycosis was associated with lesions in the oral region (90.4%; p-value = 0.000), oral pain (16.9%; p-value = 0.000), and hoarseness (14.5%; p-value = 0.008). In leishmaniasis, lesions in oral regions were not associated with oral pain and were frequently located close to the nasal area. The manifestations cited above could improve the differential diagnosis of leishmaniasis and paracoccidioidomycosis, and thereby potentially aid in the choice of appropriate confirmatory diagnostic testing.