Chromoblastomycosis

Background

Mostly members of the family Herpotrichiellaceae within the order Chaetothyriales
Fonsecaea species
- Fonsecaea pedrosoi (most common), which is present in Brazil, Mexico, Sri Lanka, Japan, and Madagascar
- F. monophora and F. pugnacius, which both have neurotropism
- F. nubica
Cladophialophora species
- Cladophialophora carrionii
- Cladophialophora samoensis
Cladosporium carrionii
Phialophora verrucosa
Rhinocladiella aquaspersa
Exophiala species, which is a black yeast-like mold
- Exophiala dermatitidis

Known by many names worldwide, including chapa (Cuba), figueira or formigueiro (Brazil), sundo or sustra (South America), foratra, gajo-miala, or didra (Madagascar)
Other medical names include black or yellow blastomycosis

More common in tropics and subtropics worldwide
In the US, Fonsecaea pedrosoi, Fonsecaea monphora, and Phialophora verrucosa
Higher rates in Mexico, Brazil, other parts of northern South America, Madagascar, and China
Relatively high rate in Japan, as well

Chronic localized fungal infection of the skin and subcutaneous tissue that produces raised, scaly lesions, usually in the lower extremities
- Lesions are warty, cauliflower-like
- Does not usually involve deeper structures like muscle or bone
Typically an implantation infection secondary to traumatic inoculation
- Plants: wood, straw, grass, thorns, palm trees, bamboo, coconut shells, cacti
- Animals: insect stings, cow stomp, buck rear, cock spine, caterpillars, leeches
- Farming tools: hoes, axes, knives, and mills
- May be associated with natural disasters (hurricanes and flooding), motor vehicle collisions, bricks, and shoes
Severity based on

Fungi
- Other implantation mycoses: sporotrichosis, eumycetoma, and lacaziosis
- Dimorphic fungi
Bacteria
- Cutaneous non-tuberculous mycobacteria
- Leprosy
- Nocardiosis
- Actinomycosis
- Yaws
- Tertiary syphilis
Parasites
- Leishmaniasis
- Rhinosporidioisis
Viruses: Human papilloma virus
Non-infectious causes
- Squamous cell carcinoma
- Mycosis fungoides (cutaneous T-cell lymphoma)
- Sarcoidosis
- Systemic lupus serythematosus

Skin scrapings or skin biopsy followed by histology and culture
- Try to get areas where there are black specks ("cayenne pepper")
Histology
- Pathognomonic muriform cells (copper penny cells)
Culture
- Resistant to cycloheximide
- May take up to 6 weeks to grow

Surgical excision is the main therapy
Can also treat with cryotherapy, laster therapy, or heat therapy
Antifungals include itraconazole, posaconazole, isavuconazole, and terbinafine
- Fonsecaea species are relatively difficult to treat