What are the other Names for this Condition? (Also known as/Synonyms)

• Chromomycosis
• Fonseca Disease
• Pedroso Disease

What is Chromoblastomycosis? (Definition/Background Information)

• Chromoblastomycosis is a tropical infection of the skin and subcutaneous tissues that is caused by many fungal species, such as Phialophora verrucose or Fonsecaea pedrosoi, which are found in soil and decaying organic matter
• This chronic infection is marked by the formation of raised and crusted itchy skin lesions usually on the hands and legs, along-with swelling of the involved limbs. Chromoblastomycosis may present similar features to many other cutaneous infections
• The condition is generally difficult to treat. The treatment of Chromoblastomycosis may involve antifungal medications, heat or cold therapy, and surgery to remove dead tissues. The prognosis of the infection depends on early diagnosis and adequate treatment support

Who gets Chromoblastomycosis? (Age and Sex Distribution)

• Chromoblastomycosis is a fungal infection that can affect individuals of all ages, although most of the affected individuals are between 30 to 50 years old
• Both males and females are affected; although, a male predilection is noted (male-female ratio is 2:1)
• The infection is commonly seen in the tropical and subtropical regions of the world
• Individuals of all racial and ethnic groups may be affected. Madagascar and Japan reportedly present a high number of cases

What are the Risk Factors for Chromoblastomycosis? (Predisposing Factors)

• Exposure to the causative fungi is the main risk factor for Chromoblastomycosis
• People living in or traveling to countries with tropical and subtropical climates have a greater risk for infection, particularly in the rural regions
• Walking barefoot or playing in soil without adequate protection of the feet
• Farmers, agriculture workers, and gardeners have a higher risk in the endemic areas
• Genetic factors - correlation with HLA-A29 is rarely noted

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Chromoblastomycosis? (Etiology)

Chromoblastomycosis is a fungal infection of skin that may be caused by any of the following pathogens:

• Cladophialophora bantiana
• Cladophialophora carrionii
• Fonsecaea compacta
• Fonsecaea pedrosoi
• Phialophora verrucosa
• Rhinocladiella aquaspersa

The fungi are commonly found in soil, organic matter, and decaying wood or plants, in hot-wet climates. Individuals are mostly infected following a minor skin injury, such as when they step on a thorn or from wood splintering. Chromoblastomycosis is a slowly progressing infection. The period of incubation (time between first infection to onset of initial symptoms) may vary from a few months to several years.

What are the Signs and Symptoms of Chromoblastomycosis?

The signs and symptoms of Chromoblastomycosis may include:

• Appearance of a small papule (raised bump on skin) with reddish discoloration, at the site of previous minor trauma (such as splinter entry)

However, since many months to years may have passed before the first onset of Chromoblastomycosis, the affected individuals may have long forgotten the events related to the minor injury.

• No pain or discomfort may be noted initially as the papule grows, extremely slowly
• The papule turns into a dry nodule presenting scarring at the center
• Limb enlargement may be noted (elephantiasis)
• Slowly, multiple skin lesions may form in the vicinity of the original lesion (satellite lesions)
• These are raised and crusty in appearance
• Ulceration of the skin lesions
• The multiple lesions may fuse together to form a large lesion
• Severe itchiness may be noted
• The hands and feet are commonly affected, but any area of the body may be involved

How is Chromoblastomycosis Diagnosed?

Chromoblastomycosis is diagnosed on the basis of the following information:

• Physical examination and a complete medical history
• Bacterial culture of pus swabs
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Potassium hydroxide (KOH) preparation: Microscopic observation of a sample to detect fungal infections
• Skin biopsy: A skin tissue biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Culture of skin tissue for fungi and atypical mycobacterial organisms

A differential diagnosis may be undertaken to exclude other medical conditions that present similar signs and symptoms. These may include:

• Atypical mycobacterium infection
• Cutaneous squamous cell carcinoma
• Discoid lupus erythematosus
• Leishmaniasis
• Leprosy
• Psoriasis
• Sporotrichosis
• Syphilis
• Tuberculosis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Chromoblastomycosis?

The complications of Chromoblastomycosis may include:

• Emotional stress due to cosmetic concerns
• Lymphedema causing swollen limbs
• Permanent scarring of skin
• Recurrent and superimposed infections
• The infection can spread via the blood and lymphatic system to other body tissues and regions
• Malignant transformation to squamous cell carcinoma (in rare cases)

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Chromoblastomycosis Treated?

A treatment of Chromoblastomycosis is difficult, challenging, and time-consuming. It may involve the following measures:

• Administration of antifungal medications such as itraconazole, 5- flucytosine, terbinafine, amphotericin B, voriconazole, or posaconazole
• Antibacterial (antibiotic) therapy for secondary infections
• Cryotherapy
• Surgical debridement of tissues

How can Chromoblastomycosis be Prevented?

Avoiding exposure to the causative fungi can help prevent Chromoblastomycosis.

What is the Prognosis of Chromoblastomycosis? (Outcomes/Resolutions)

• The prognosis of Chromoblastomycosis is dependent upon the severity of the signs and symptoms and associated complications, if any
• Small and localized lesions are known to respond well to treatment, while larger and diffused lesions may be difficult to treat
• In very rare cases, Chromoblastomycosis is known to resolve spontaneously

Additional and Relevant Useful Information for Chromoblastomycosis:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/