What the physicians should know about mast cells, dendritic cells, urticaria, and omalizumab during COVID-19 or asymptomatic infections due to SARS-CoV-2?

Coronavirus disease (COVID-19) pandemic presents several dermatological manifestations described in the present indexed literature, with around 700 cases reported until May 2020, some described as urticaria or urticarial rashes. Urticaria is constituted by evanescent erythematous-edematous lesions (wheals and flare), which does not persist in the same site for more than 24 to 48 hours and appears in other topographic localization, resolving without residual hyper pigmentation. During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, some cytokines are synthesized, including Interferon (IFN) type I, TNF-α, and chemokines which may induce mast cells (MCs) and basophils degranulation by mechanisms similar to the autoinflammatory monogenic or polygenic diseases. In this article, we discuss the spectrum of the urticaria and urticarial-like lesions in the COVID-19's era, besides other aspects related to innate and adaptative immune response to viral infections, interactions between dermal dendritic cells and MCs, and degranulation of MCs by different stimuli. Plasmacytoid dendritic cells share, in allergic patients, expression of the high-affinity IgE receptors on cell membranes and demonstrated a low pattern of type I IFN secretion in viral infections. We discuss the previous descriptions of the effects of omalizumab, a monoclonal antibody directed to IgE and high-affinity IgE receptors, to improve the IFN responses and enhance their antiviral effects.

Immunopathological characterization of human cutaneous leishmaniasis lesions caused by Leishmania (Viannia) spp. in Amazonian Brazil.

American cutaneous leishmaniasis (ACL) is a chronic infectious disease caused by different protozoan species of Leishmania, and it is endemic in both tropical and subtropical countries. Using immunohistochemistry, we investigate the density of CD68+, lysozyme+, CD1a+, factor XIIIa+, CD4+, CD8+, CD56+, interferon (IFN)-γ+, and inducible NO synthase (iNOS+) cells. These cells were analyzed from 22 biopsy samples obtained from the lesions of ACL patients, whose infection was caused by Leishmania (Viannia) spp. Histopathological analysis showed dense mononuclear inflammatory infiltration in the dermis, which was composed of lymphocytes, macrophages, plasma cells, and discrete tissue parasitism. Granulomatous reactions were also present in the majority of cases. The density of the activated macrophages was higher than that of inactivated macrophages in the lesions. The density of Langerhans cells (CD1a+) was lower than that of dermal dendrocytes (factor XIIIa+). The density of CD8+ T lymphocytes was higher than that of CD4+ T lymphocytes. The cellular density of these immunological markers in relation to the species of Leishmania demonstrated that L. (Viannia) sp. lesions had higher IFN-γ expression than that Leishmania (Viania) braziliensis lesions. The evaluation of these markers, according to disease progression, did not reveal any significant differences. L. (Viannia) sp. infection leads to a favorable immune response in the host, as predominantly represented by lysozyme+, factor XIIIa+, CD8+ T cells, and the expression of (IFN)-γ+ at the lesion site.

Topical application of imiquimod as a treatment for chromoblastomycosis.

Chromoblastomycosis is a subcutaneous mycosis that remains a therapeutic challenge, with no standard treatment and high rates of relapse. On the basis of our recent discoveries in mouse models, we tested the efficacy of topical applications of imiquimod to treat patients afflicted with this chronic fungal infection. We report results of treatment for the first 4 recipients of topical imiquimod, all of whom displayed a marked improvement of their lesions, both with and without concurrent oral antifungal therapy.

Chromoblastomycosis: New Perspective on Adjuvant Treatment with Acitretin.

Chromoblastomycosis (CBM) is a neglected human disease, caused by different species of pigmented dematiaceous fungi that cause granulomatous and suppurative dermatosis. This infection is difficult to treat and there are limited therapeutic options, including terbinafine, itraconazole, and tioconazole. Classic treatment is administered for a long period of time, but some patients do not respond properly, and therefore, such therapeutic approaches possess low cure rates. Therefore, it is vital to develop new strategies for the treatment of CBM. In this regard, it has been observed that the association of immunomodulatory molecules such as glucan with therapy carried out with antifungal drugs improves cutaneous lesions in comparison to treatment with antifungal drugs alone, suggesting that drug association may be an interesting and significant approach to incorporate into CBM therapy. Thus, the aim of this work was to associate classical antifungal therapy with the adjuvants imiquimod and acitretin. In the present case, we reported a patient with extensive CBM caused by Fonsaecae pedrosoi, that affected an extensive area of the right leg, that was left without treatment for 11 years. He was treated with a classical combination of itraconazole and terbinafine via the oral route plus topical imiquimod and oral acitretin, as an adjuvant therapy. After five months of treatment, a significant regression of verrucous plaques was observed, suggesting that the use of these adjuvants combined with the classical antifungal drugs, intraconazole plus terbinafine, can reduce treatment time and rapidly improve the patient's quality of life. This result confirms that the use of coadjuvant drugs may be effective in the treatment of this infectious disease.

New Immunological Markers in Chromoblastomycosis-The Importance of PD-1 and PD-L1 Molecules in Human Infection.

The pathogenesis of chromoblastomycosis (CBM) is associated with Th2 and/or T regulatory immune responses, while resistance is associated with a Th1 response. However, even in the presence of IFN-γ, fungi persist in the lesions, and the reason for this persistence is unknown. To clarify the factors associated with pathogenesis, this study aimed to determine the polarization of the cellular immune response and the densities of cells that express markers of exhaustion in the skin of CBM patients. In the skin of patients with CBM, a moderate inflammatory infiltrate was observed, characterized primarily by the occurrence of histiocytes. Analysis of fungal density allowed us to divide patients into groups that exhibited low and high fungal densities; however, the intensity of the inflammatory response was not related to mycotic loads. Furthermore, patients with CBM exhibited a significant increase in the number of CD4+ and CD8+ cells associated with a high density of IL-10-, IL-17-, and IFN-γ-producing cells, indicating the presence of a chronic and mixed cellular immune response, which was also independent of fungal load. A significant increase in the number of PD-1+ and PD-L1+ cells was observed, which may be associated with the maintenance of the fungus in the skin and the progression of the disease.

Cutaneous larva migrans: a bad souvenir from the vacation.

Cutaneous larva migrans (CLM) is a common endemic disease in tropical and subtropical countries. This condition is caused by skin-penetrating larvae of nematodes, mainly of the hookworm Ancylostoma braziliense and other nematodes of the family Ancylostomidae. We report three cases of CLM acquired during vacations in different regions of Brazil.

Primary Cutaneous Cryptococcosis Caused by Cryptococcus gatti in an Elderly Patient.

According to the spread of Cryptococcus sp., fungal infections can be classified as primary or secondary. In primary cutaneous cryptococcosis, the fungi are restricted to the skin of the patients, without systemic involvement. The incidence of primary cutaneous cryptococcosis is high in patients with immunosuppression, and this type of infection is rarely observed in patients who are immunocompetent. In the present case report, a patient who is immunocompetent and has systemic comorbidity reported that, after skin trauma, ulcerovegetative lesions appeared in the right upper arm; the etiologic agent was identified as Cryptococcus gatti, serotype B. The cutaneous lesions healed completely after 5 months of fluconazole treatment.

Reviewing the Etiologic Agents, Microbe-Host Relationship, Immune Response, Diagnosis, and Treatment in Chromoblastomycosis.

Chromoblastomycosis (CBM) is a neglected human disease, caused by different species of pigmented dematiaceous fungi that cause subcutaneous infections. This disease has been considered an occupational disease, occurring among people working in the field of agriculture, particularly in low-income countries. In 1914, the first case of CBM was described in Brazil, and although efforts have been made, few scientific and technological advances have been made in this area. In the field of fungi and host cell relationship, a very reduced number of antigens were characterized, but available data suggest that ectoantigens bind to the cell membrane of host cells and modulate the phagocytic, immunological, and microbicidal responses of immune cells. Furthermore, antigens cleave extracellular proteins in tissues, allowing fungi to spread. On the contrary, if phagocytic cells are able to present antigens in MHC molecules to T lymphocytes in the presence of costimulation and IL-12, a Th1 immune response will develop and a relative control of the disease will be observed. Despite knowledge of the resistance and susceptibility in CBM, up to now, no effective vaccines have been developed. In the field of chemotherapy, most patients are treated with conventional antifungal drugs, such as itraconazole and terbinafine, but these drugs exhibit limitations, considering that not all patients heal cutaneous lesions. Few advances in treatment have been made so far, but one of the most promising ones is based on the use of immunomodulators, such as imiquimod. Data about a standard treatment are missing in the medical literature; part of it is caused by the existence of a diversity of etiologic agents and clinical forms. The present review summarizes the advances made in the field of CBM related to the diversity of pathogenic species, fungi and host cell relationship, antigens, innate and acquired immunity, clinical forms of CBM, chemotherapy, and diagnosis.

Lymphocutaneous Sporotrichosis Refractory to First-Line Treatment.

Sporotrichosis is a fungal infection endemic in Latin America and has been attributed to the thermodimorphic fungus of the genus Sporothrix. Transmission to humans occurs during a traumatic injury with soil or organic material; additionally, lesions caused by infected cats play an important role in the epidemiology of the disease. The classic treatment of sporotrichosis is performed with itraconazole or potassium iodide; second-line medications, such as amphotericin B and terbinafine, can alternatively be used in cases of first-line drug failure. In the present study, a patient with lymphocutaneous sporotrichosis in the right upper limb exhibited intolerance to itraconazole and potassium iodide, additionally during the period of use; these drugs did not control skin lesions. In this patient, amphotericin B deoxycholate and its liposomal version were used in this patient; and complete recovery of the lesions was observed.

A case of tuberculosis verrucosa cutis in Brazil undiagnosed for 15 years.

Tuberculosis verrucosa cutis is a rare medical condition that is caused by the inoculation of Mycobacterium tuberculosis into the skin of a previously sensitized individual. This clinical form of tuberculosis corresponds to 1-2% of all cases of tuberculosis and due to the paucibacillary characteristic of the lesions, patients can be misdiagnosed, accounting for the chronification of the skin infection. Herein, we report the case of a 26-year-old male farmer, presenting plaques with verrucosa and hyperkeratosis features in the left thigh and buttocks during 15 years. M. tuberculosis was identified by PCR and the patient was treated with standard anti-tuberculosis drugs, with subsequent improvement of the skin lesions.

Managing chromoblastomycosis with acitretin plus imiquimod: A case report on the improvement of cutaneous lesions and reduction of the treatment time.

Chromoblastomycosis (CBM) is an infectious disease caused by fungi that is prevalent in tropical and subtropical countries. Besides few therapeutic options, the classical treatment of CBM needs to be administrated for a long period of time, and unfortunately some patients do not show improvement of the lesions. Thus, it becomes urgent to develop new strategies for the treatment of CBM. This work reports a successful treatment, performed with the combination of oral acitretin (50 mg/kg, once a day) plus topical imiquimod (50 mg/g, five times per week) for 5 months in a patient with CBM. A significant improvement of the lesions was observed in the 1st month, and in the 5th a complete regression of lesions was recorded. Changes in the biochemical parameters were not observed. These data suggest that the combination of acitretin and imiquimod may be effective at treating CBM.

Case Report: Treatment of Chromoblastomycosis with Combinations including Acitretin: A Report of Two Cases.

Chromoblastomycosis is a cutaneous fungal infection caused by dematiaceous fungi that belong to the order Chaetothyriales and family Herpotrichiellaceae. This infection is prevalent in tropical and subtropical areas and has been designated as a neglected tropical disease according to the WHO. Chromoblastomycosis infection is difficult to treat, and there are limited therapeutic options, making urgent the characterization of new medicines or approaches to treat such infection. In the present case report, two patients with extensive chromoblastomycosis lesions were treated with the combination of itraconazole, acitretin, and imiquimod. In the fourth month of treatment, both patients showed improvement of verrucous plates, suggesting that acitretin combined with drugs already used in chromoblastomycosis therapy can decrease the time of treatment, improving patient's quality of life.

Successful treatment of chromoblastomycosis caused by Fonsecaea pedrosoi using imiquimod.

Chromoblastomycosis (CBM) is a fungal infection caused by fungi belonging to the order Chaetothyriales, and caused mainly by Fonsecaea pedrosoi. The classic treatment, based on itraconazole and/or terbinafine as well as physical approaches, is considered complex and ineffective due to the high rate of relapses. Thus, new strategies are needed to manage CBM; in this regard, the present work reports the evolution of lesions in patients successfully treated with imiquimod. Of note, classic treatment was not effective in healing the lesions of two of them, but single topical treatment with imiquimod healed the lesions.

Donovanosis treated with thiamphenicol.

Ten patients with donovanosis were treated with thiamphenicol for two weeks. In eight of them, included two HIV infected patients, lesions healed. The safety profile of thiamphenicol makes it a useful and cost-effective agent in the management of donovanosis. Randomized controlled trials should be conducted with these treatment options.

Macrophage subtypes in recurrent nodular basal cell carcinoma after Mohs micrographic surgery.

BACKGROUND: The macrophages associated with solid tumors are related to the progression or regression of tumors, depending on the differentiation in M1 or M2. M2 subtype promotes angiogenesis, remodeling, and tissue repair (tumor proliferation). In contrast, M1 produces toxic mediators and presents antigens, destroying microorganisms and tumor cells. The microenvironment of most aggressive forms of basal cell carcinoma (BCC) shows an increase in macrophages due to M2 phenotype compared to noninvasive forms. The treatment of nodular BCC by Mohs micrographic surgery (MMS) provides high cure rates, but relapses can occur. AIMS: To compare the total population of macrophages and their subpopulations M1 and M2 in cases of recurrent and nonrecurrent nodular BCC after excision by MMS. MATERIALS & METHODS: Histological sections obtained from paraffin blocks of nine cases of recurrent nodular BCC after MMS and 18 cases of nonrecurrent nodular BCC operated by MMS were immunostained for iNOS, CD204, CD163, and CD68. The expression of these markers was analyzed by image analysis. RESULTS: No significant differences were found between the groups in relation to the average percentage of M1 cells, M2 cells, and total cells. DISCUSSION AND CONCLUSION: A relationship was not seen between tumor-associated macrophages (TAM) and tumor recurrence.

Tungiasis under dermoscopy: in vivo and ex vivo examination of the cutaneous infestation due to Tunga penetrans.

The female flea Tunga penetrans is responsible for a cutaneous parasitosis known as Tungiasis. We report the clinical case of a 12 year-old Caucasian boy who sought treatment in a dermatological private office due to a painful lesion in the plantar area and whose dermoscopic examination, without skin contact, allowed the visualization of parasite's movement inside the skin. The diagnosis of tungiasis is clinical, but it can be aided by in vivo and ex vivo dermoscopic examination of the lesion.