China
Africa
Explore chapters and articles related to this topic
Fungal Infections
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Uwe Wollina, Pietro Nenoff, Shyam Verma, Uta-Christina Hipler
Chromoblastomycosis or chromomycosis is a chronic polymorphic fungal infection of the skin and subcutaneous tissue. It is caused by several species of melanized or dematiaceous fungi, which produce a dark pigment. The fungus penetrates the skin through a skin injury. About 4–8 weeks later, a papule develops that progresses to a slow-growing warty nodule.
Ketoconazole
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissues caused by dematiaceous fungi (most commonly Fonsecaea pedrosoi, Philaophora verrucosa, Cladosporium carrionii), which are found in soil and decomposing vegetation and innoculated into skin by trauma. It is generally difficult to treat. Most infections caused by dematiaceous fungi require both surgical and medical treatment. Ketoconazole (200–400 mg daily) therapy for several months produced a moderate improvement in 30% of patients with mild disease. It is not effective in those with extensive disease (Restrepo, 1994). Cutaneous chromomycosis due to F. pedrosoi was reported in a renal transplant patient who required multiple excision biopsies and ketoconazole to effectively control her disease. Although residual skin lesions regressed over several months of treatment, they did not disappear, and recurrent lessions developed while she was taking ketoconazole 200 mg daily. New crops of lesions were excised and the patient remained free of disease for 1 year on continued ketoconazole (Wackym et al., 1985). Successful treatment with ketoconazole and flucytosine in combination has also been reported (Silber et al., 1983). At present, itraconazole is considered to be the drug of choice (Queiroz-Telles et al., 1992). Other medical therapeutic options include 5-flucytosine, terbinafine, fluconazole, thiabendazole, and amphotericin B (Martinez and Mendez Tovar, 2007).
Nail specific conditions
Published in Eckart Haneke, Histopathology of the NailOnychopathology, 2017
In Central Europe, onychomycosis nigricans is seen due to some strains of Trichophyton rubrum var. nigricans that produce a soluble melanin-type pigment, whereas molds are more common in hot climate.62 The soluble fungal melanin is seen as a diffuse yellow color both in H&E and PAS stained nails. One case of melanonychia was seen due to Medlar bodies.63 These are sclerotic or muriform cells of several dematiaceous pigmented fungi and are characterized by three-dimensional septation; common causes of chromoblastomycosis are Fonsecaea pedrosoi, Fonsecaea compacta, Cladosporium carrionii, Phialophora verrucosa, Rhinocladiella aquaspersa, and Aureobasidium pullulans. The fungi are identified by PAS or Grocott stains. We have seen thick-walled pigmented spores in a wooden splinter under the nail in a female patient without the history of travel to subtropical or tropical regions (Figure 4.22). Darkly pigmented spores and hyphae were also seen in a patient with onychogryphosis (Figure 4.20).
Aspartic peptidase of Phialophora verrucosa as target of HIV peptidase inhibitors: blockage of its enzymatic activity and interference with fungal growth and macrophage interaction
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Marcela Q. Granato, Ingrid S. Sousa, Thabatta L. S. A. Rosa, Diego S. Gonçalves, Sergio H. Seabra, Daniela S. Alviano, Maria C. V. Pessolani, André L. S. Santos, Lucimar F. Kneipp
Phialophora verrucosa is a dematiaceous fungus associated with several diseases including chromoblastomycosis (CBM), phaeohyphomycosis and mycetoma1–3. However, the main mycosis caused by this fungus is CBM4. Although no gold standard therapy for CBM has been proposed, itraconazole is the most commonly used antifungal agent. It also may be combined with other drugs and/or physical methods such as surgery removal and thermotherapy5. However, infections caused by CBM fungi, especially P. verrucosa are refractory to available therapies and quite difficult to treat3,6. Thus, the main challenges to combat those debilitating fungal infections are the search for new targets and novel therapeutic approaches. Little is known about the mechanisms used by P. verrucosa to promote diseases. Most studies are based on taxonomical, clinical and epidemiological researches6,7. Fungal pathogenesis is related to several factors including melanin, dimorphism and hydrolytic enzymes8. Enzymes as peptidases are produced by several pathogenic fungi and can modulate essential fungal cell events, such as nutrition, growth, differentiation, biofilm formation, signalling and cell death pathways, as well as invasion and evasion of host cells9,10. In the last years, our research group has shown that Fonsecaea pedrosoi, another aetiological agent of CBM, is able to secrete different proteolytic enzymes involved with growth, cell differentiation and fungal pathogenesis11–15. In the previous study, we detected an extracellular metallopeptidase activity on P. verrucosa and showed that this enzyme could be involved with fungal growth and cellular differentiation16.