Chromoblastomycosis

Chromoblastomycosis is one of the most frequent fungal infections caused by the transcutaneous inoculation of propagules (spores) from several species of melanized fungi. It has attracted a lot of attention because of the increased incidence of tropical and subtropical climates. As an advanced leader in drug discovery, Creative Biolabs combines our first-class technologies and long-term scientific expertise in the field of antifungal drug discovery. We provide a full series of antifungal drug discovery services against various fungal infections, including chromoblastomycosis.

Introduction of Chromoblastomycosis

The human mutilating disease chromoblastomycosis, also known as chromomycosis, cladosporiosis, Fonseca's disease, Pedroso's disease, phaeosporotrichosis, or verrucous dermatitis, is a long-term cutaneous infection affecting normal, immunocompetent people mostly in tropical or subtropical areas. It is characterized by formation of papillomatous nodules that tend to ulcerate.

Fig.1 Global distribution of chromoblastomycosis. (Queiroz-Telles, 2017)

Chromoblastomycosis is caused by melanized members of the order Chaetothyriales, including dark brown or black fungi that produce sclerotic bodies in tissue. The most commonly observed causative agents causing chromoblastomycosis include:

• Fonsecaea Pedrosoi
• Cladophialophora Carrionii
• Phialophora Verrucosa
• Rhinocladiella Aquaspersa
• Exophiala Jeanselmei
• Exophiala Spinifera

Symptoms and Signs

Usually, the progress of chromoblastomycosis is very slow, presenting various stages in the clinic.

• It starts as a small, itchy, enlarging papules on exposed skin such as the foot or hand.
• These papules slowly extend to form dull red or violaceous, sharply demarcated patches with indurated bases and may be at least partial clearing with scarring in the center of the lesion.
• Dull red or grayish cauliflower-shaped nodular projections develop in the center of patches, gradually extending to cover extremities.
• Obstructed lymphatics, persisting itches, and secondary bacterial superinfections may develop, causing ulcerations and occasionally septicemia.

Diagnosis of Chromoblastomycosis

Late phase of chromoblastomycosis lesions have a characteristic appearance, but the early lesions may be mistaken for dermatophytoses. At present, the diagnosis of chromoblastomycosis mainly relies on microscopy and culture of scrapings or pus swabs. Fontana-Masson staining for melanin can help to confirm the presence of the dematiaceous fungus, which is pathognomonic and may show typical thick-walled dark-brown cells on skin biopsy.

Fig.2 Cultures of chromoblastomycosis pathogens. (Hernández-Hernández, 2018)

Treatment of Chromoblastomycosis

Treatment of chromoblastomycosis is difficult and prolonged, with the rarely spontaneous recovery. Antibiotics are the most commonly used treatment in the clinic. Notably, antibiotics may be used to treat bacterial superinfections in the course of disease.

Prevention of Chromoblastomycosis

There has no effective preventive measure is discussed aside from avoiding the traumatic inoculation of fungi. It is documented that walking barefoot in endemic areas has a correlation with the occurrence of chromoblastomycosis on the foot. So it is necessary to abstain walking barefoot to reduce the incidence of infection.

Creative Biolabs is dedicated to partnering with you to address your research requirements in the study of chromoblastomycosis, and our expert scientific staff has extensive experience with difficult projects. We will spare no effort to advance your research and programs in antifungal drug development. Please feel free to contact us for more information.

References

1. Queiroz-Telles, F.; et al. Chromoblastomycosis. Clin Microbiol Rev. 2017, 30(1):233-276.
2. Hernández-Hernández, F.; et al. First case of chromoblastomycosis due to Phoma insulana. Enfermedades infecciosas y microbiologia clinica (English ed.). 2018, 36(2): 95-99.

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