In many cases, the patient will not notice or remember the initial trauma, as symptoms often do not appear for years. The fungi most commonly observed to cause chromoblastomycosis are:

Fonsecaea pedrosoi
Cladophialophora bantiana causes both cutaneous chromoblastomycosis and systemic phaeohyphomycosis
Phialophora verrucosa
Cladophialophora carrionii
Fonsecaea compacta

Mechanism
Over months to years, an erythematous papule appears at the site of inoculation. Although the mycosis slowly spreads, it usually remains localized to the skin and subcutaneous tissue. Hematogenous and/or lymphatic spread may occur. Multiple nodules may appear on the same limb, sometimes coalescing into a large plaque. Secondary bacterial infection may occur, sometimes inducing lymphatic obstruction. The central portion of the lesion may heal, producing a scar, or it may ulcerate. Diagnosis
The most informative test is to scrape the lesion and add potassium hydroxide (KOH), then examine under a microscope. (KOH scrapings are commonly used to examine fungal infections.) The pathognomonic finding is observing medlar bodies (also called muriform bodies or sclerotic cells). Scrapings from the lesion can also be cultured to identify the organism involved. Blood tests and imaging studies are not commonly used.On histology, chromoblastomycosis manifests as pigmented yeasts resembling "copper pennies". Special stains, such as periodic acid schiff and Gömöri methenamine silver, can be used to demonstrate the fungal organisms if needed. Prevention
No preventive measure is known aside from avoiding the traumatic inoculation of fungi. At least one study found a correlation between walking barefoot in endemic areas and occurrence of chromoblastomycosis on the foot. Treatment
Chromoblastomycosis is very difficult to cure.
Pralatrexate, sold under the brand name Folotyn, is a medication used for the treatment of relapsed or refractory peripheral T-cell lymphoma (PTCL).Pralatrexate was approved for medical use in  the United States in September 2009, as the first treatment for Peripheral T-cell Lymphoma (PTCL), an often aggressive type of non-Hodgkins lymphoma. Medical uses
Pralatrexate is indicated for the treatment of people with relapsed or refractory peripheral T-cell lymphoma (PTCL). Mechanism
Pralatrexate is a dihydrofolate reductase inhibitor. Discovery
Research on this class of drugs began in the 1950s at SRI International, where scientists were focused on developing new chemotherapies and antifolates that would be effective against tumor cells.In the late 1970s, researchers at Memorial Sloan Kettering Cancer Center discovered that cancerous cells take in natural folate through a protein identified as plasma membrane transporter (now referred to as "reduced folate carrier type 1" or "RFC-1"). Further research showed that when normal cells evolve into cancerous cells they often overproduce RFC-1 to ensure they get enough folate.A subsequent scientific collaboration was ultimately formed among SRI International, Memorial Sloan Kettering Cancer Center, and the Southern Research Institute with the intention of developing an antifolate with greater therapeutic selectivity – an agent that could be more effectively internalized into tumors (transported into the cells through RFC-1) and would be more toxic to cancer cells than normal cells.This collaboration, supported by the National Cancer Institute, led to the identification of pralatrexate in the mid-1990s. Pralatrexate was later licensed to Allos Therapeutics in 2002 for further development.