Abstract COVID-19 disease caused by the SARS-CoV-2 coronavirus causes a wide range of clinical manifestations, ranging from mild to severe, with the main ones affecting the respiratory tract, such as pneumonia. In patients with greater severity, the high frequency of bacterial and fungal coinfection stands out, a situation related both to the patient’s pre-existing comorbidities and due to the hospitalization itself. Cases of mucormycosis associated with COVID-19 were highlighted in the lay and scientific media, with the increase in mycosis cases being directly and indirectly attributed to the viral infection. This report describes a case of rhino-orbito-cerebral mucormycosis in a diabetic patient hospitalized for COVID-19, whose diagnosis was confirmed by identifying the agent Rhizopus microsporus var. microsporus through culture for fungi and PCR examination.

Abstract The detection of muriform cells in direct mycological or anatomopathological examination is considered pathognomonic for chromoblastomycosis. The morphological aspect that these fungal structures acquire were called “Borelli spiders”, when associated with hyphae. Reports of this association have been described for decades, initially related to more pathogenic agents of this mycosis. More recent studies have shown aspects related to the host's immunity that participate in this process, as well as an association with a worse disease prognosis. The present study discloses the findings of complementary examinations with the presence of “Borelli’s spiders” in a patient diagnosed with chromoblastomycosis.

Abstract Currently, pagetoid dyskeratosis is believed to involve an accelerated keratinization process, possibly induced by mechanical trauma. It represents, in almost its totality, incidental histological findings of specific cells, except when it occurs in the hands, where it usually occurs simultaneously with skin lesions and local dyschromia. These are large, rounded keratinocytes, with pale cytoplasm and a pyknotic nucleus surrounded by a clear halo, which can be easily mistaken by other skin diseases. Its etiology is not completely elucidated, and the correct identification of this entity can be of great importance in the differential diagnosis of skin disorders and the understanding of the keratinization process of the epidermis.

Abstract Background American cutaneous leishmaniasis is an infectious dermatosis caused by protozoa of the genus Leishmania, which comprises a broad spectrum of clinical manifestations depending on the parasite species involved in the infections and the immunogenetic response of the host. The use of techniques for amplification of the parasites DNA based on polymerase chain reaction polymerase chain reaction and the recent application of combined techniques, such as high-resolution DNA dissociation, have been described as a viable alternative for the detection and identification of Leishmania spp. in biological samples. Objectives To identify the Leishmania species using the polymerase chain reaction high-resolution DNA dissociation technique in skin biopsies of hospital-treated patients, and compare with results obtained by other molecular identification techniques. Methods A retrospective study assessing patients with suspected American cutaneous leishmaniasis seen at a hospital in São Paulo/Brazil was conducted. The paraffin blocks of 22 patients were analyzed by polymerase chain reaction high-resolution DNA dissociation to confirm the diagnosis and identify the species. Results Of the 22 patients with suspected American cutaneous leishmaniasis, the parasite was identified in 14, comprising five cases (35.6%) of infection by L. amazonensis, four (28.5%) by L. braziliensis, two (14.4%) by L. amazonensis + L. infantum chagasi, two (14.4%) by L. guyanensis, and one (7.1%) by Leishmania infantum chagasi. In one of the samples, in which the presence of amastigotes was confirmed on histopathological examination, the polymerase chain reaction high-resolution DNA dissociation technique failed to detect the DNA of the parasite. Study limitations The retrospective nature of the study and small number of patients. Conclusions The method detected and identified Leishmania species in paraffin-embedded skin biopsies with a sensitivity of 96.4% and could be routinely used in the public health system.

Abstract Pseudomycetoma is an extremely rare deep mycosis, caused by dermatophytic fungi that penetrate the tissue from infected follicles of tinea capitis. Both clinically and histopathology are similar to eumycetoma, being distinguished through the isolation of the fungus, which in the case of pseudomycetoma can be Microsporum spp. or Trichophyton spp. genre. We present a 24-year-old man with an exuberant tumor in the occipital region with fistula, whose histopathological examination evidenced grains composed of hyaline hyphae and the culture for fungi isolated the agent Microsporum canis. Combined treatment of surgical excision followed by oral griseofulvin for two years was performed, with resolution of the condition.

Abstract Background: Anogenital warts are the leading sexually transmitted infection in patients seeking care at specialized clinics. They may display a vast array of forms, according to the interaction of the virus with the host's immunity. Cellular immunity is the epithelium's main form of defense against the virus, involving an active participation of the Langerhans cells and pro-inflammatory cytokines such as TNF-α. Objective: To assess the epithelial immune response of anogenital warts in males, according to the number of lesions presented. Methods: This is a prospective, cross-sectional study carried out at the dermatology outpatient clinic in a tertiary hospital. We included male patients over 18 years of age without comorbidities who had anogenital condylomata and no previous treatments.In order to evaluate the local epithelial immunity, the lesions were quantified, then removed and employed in CD1a immunohistochemistry assays for assessing the morphometry and morphology of Langerhans cells; TNF-α; reaction was used for determining cytokine positivity in the epithelium. Results: 48 patients were included in the study. There was no statistically significant difference as to the number of Langerhans cells, in their morphology, or the presence of TNF-α. However, patients presenting with more Langerhans cells in the lesions had cells with a star-like and dendritic morphology, whereas in those with a lower cell count had cells with a rounded morphology and no dendrites (p < 0.001). Study limitations: Small number of patients analyzed. Conclusion: There was no difference in epithelial immunity between patients having few or many anogenital condyloma lesions as measured by the morphology and morphometry of Langerhans cells and TNF-α; positivity. Such an assessment employing immunity markers differing from the usual ones is expected to yield useful results.

Abstract The number of individuals with tattoos has been increasing worldwide, alongside with reports of complications varying from reactions to the injected pigments to infections caused by agents inoculated in the pigmentation process. The diagnosis of such unwanted events can be obtained through complementary non-invasive methods, preserving the maximum of the tattoo design. The authors present two cases of patients with warts on tattooing, and correlate their clinical aspects to in vivo and ex vivo dermoscopy, and to the findings in the histopathological examination, aiming to determine patterns that aid the diagnosis of these lesions without performing biopsy.

Abstract: Paracoccidioidomycosis is a fungal infection that occurs in immunocompetent patients and are classified into two forms: the acute-subacute form, predominantly in young patients, and the chronic adult form that may present classic ulcerated lesions to rare sarcoid ones. We present the case of a boy whose infection began with sarcoid lesions but, after being mistakenly diagnosed with cutaneous sarcoidosis and treated (for three years) with prednisone, developed painful ulcerations throughout the body. After the correct diagnosis, with evidence of the fungus in histopathological and mycological examinations, the patient was properly treated with itraconazole for eight months and evolved with total remission of the disease.

Abstract: Dermoscopic examination allows visualization of horizontal images on the skin, showing well-defined patterns. The authors propose ex vivo dermoscopic visualization using a vertical view of skin sections. The new image clearly distinguishes the stratum corneum, epidermis, and dermis as well as the anatomical location of the pigment. Will this new approach be useful in dermoscopic diagnosis? Further studies are needed.

Abstract: Atypical mycobacterial infections are caused by mycobacteria other than those from the M. tuberculosis complex and M. leprae. Its incidence has increased progressively, with considerable increase of scientific publications on the subject. Only 10% of the cases present with cutaneous infections, most of them related to surgical interventions and aesthetic procedures. We present a case of mycobacteriosis due to automotive accident that presented a diagnostic challenge due to its clinical presentation with lesions of sporotrichoid progression in the lymphatic system.

Abstract: Donovanosis is a chronic infectious disease caused by the Gram-negative bacteria Klebsiella granulomatis, which mainly affects the skin and mucous membranes of the genital, perigenital, and inguinal regions. Also known as venereal granuloma or granuloma inguinale, it is endemic in tropical and subtropical regions of the globe and often associated with sexual transmission. We report the case of an 11-year-old female victim of chronic sexual abuse, who was diagnosed with donovanosis and presented a good therapeutic response to doxycycline.