| Chromoblastomycosis | |
|---|---|
| Other names | Chromomycosis,[1] Cladosporiosis,[1] Fonseca's disease,[1] Pedroso's disease,[1] Phaeosporotrichosis,[1] or Verrucous dermatitis[1] |
 | |
| Micrograph of chromoblastomycosis showing sclerotic bodies | |
| Specialty | Infectious disease,Dermatology |
Chromoblastomycosis is a long-termfungal infection of the skin[2] andsubcutaneous tissue (achronicsubcutaneous mycosis).[3]
It can be caused by many different types offungi which become implanted under theskin, often by thorns or splinters.[4] Chromoblastomycosis spreads very slowly.[citation needed]
It is rarely fatal and usually has a goodprognosis, but it can be very difficult to cure. The several treatment options include medication and surgery.[5]
The infection occurs most commonly in tropical or subtropical climates, often in rural areas.[6]
The initial trauma causing the infection is often forgotten or not noticed. The infection builds at the site over the years, and a small redpapule (skin elevation) appears. The lesion is usually not painful, with few, if any symptoms. Patients rarely seek medical care at this point.[citation needed]
Several complications may occur. Usually, the infection slowly spreads to the surrounding tissue while remaining localized to the area around the original wound. However, sometimes the fungi may spread through theblood vessels orlymph vessels, producingmetastatic lesions at distant sites. Another possibility is secondary infection withbacteria. This may lead tolymph stasis (obstruction of the lymph vessels) andelephantiasis. The nodules may becomeulcerated, or multiple nodules may grow and coalesce, affecting a large area of a limb.[citation needed]
Chromoblastomycosis is believed to originate in minor trauma to the skin, usually from vegetative material such as thorns or splinters; this trauma implants fungus in the subcutaneous tissue. 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:
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.[citation needed]
The most informative test is to scrape the lesion and addpotassium hydroxide (KOH), then examine it under a microscope. (KOH scrapings are commonly used to examine fungal infections.) Thepathognomonic finding is observingmedlar bodies (also called muriform bodies or sclerotic cells). Scrapings from the lesion can also becultured 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.[citation needed]
No preventive measure is known aside from avoiding the traumatic inoculation of fungi. At least one study found a correlation between walking barefoot inendemic areas and the occurrence of chromoblastomycosis on the foot.[citation needed]
Chromoblastomycosis is very difficult to cure. The primary treatments of choice are:[citation needed]
Other treatment options are the antifungal drugterbinafine,[12] another antifungal azoleposaconazole, andheat therapy.
Antibiotics may be used to treat bacterial superinfections.[citation needed]
Amphotericin B has also been used.[13]
Photodynamic therapy is a newer type of therapy used to treat Chromoblastomycosis.[14]
The prognosis for chromoblastomycosis is very good for small lesions. Severe cases are difficult to cure, although the prognosis is still good. The primary complications are ulceration,lymphedema, and secondary bacterial infection. A few cases ofmalignant transformation tosquamous cell carcinoma have been reported. Chromoblastomycosis is very rarely fatal.[citation needed]
Chromoblastomycosis occurs globally, most commonly in rural areas in tropical or subtropical climates.[6]
It is most common in rural areas between approximately 30°N and 30°Slatitude. Over two-thirds of patients aremale, usually between the ages of 30 and 50. A correlation withHLA-A29 suggests genetic factors may play a role, as well.[15]
Chromoblastomycosis is considered aneglected tropical disease, affects mainly people living in poverty, and causes considerablemorbidity, stigma, and discrimination.[6]
