Chromoblastomycosis from a Non-endemic Area and Response to Itraconazole.

Chromoblastomycosis belongs to the heterogeneous group of subcutaneous mycoses. It is caused by various pigmented (dematiaceous) fungi, which gain entry into the skin via traumatic implantation. We would like to share a case report of chromoblastomycosis in a 32-year-old male, who presented to us with 3 years history of slowly progressive, itchy, verrucous, crusted lesions over right forearm and arm. He is being treated with itraconazole 100 mg twice daily. The case is of interest because it has so far not been reported from our region- the northwest arid zone of India. The patient showed favorable response to itraconazole.

What was known?

Chromoblastomycosis is endemic in the warm and humid regions of the country. Azoles are known to be of therapeutic benefit.

Introduction

Chromoblastomycosis is a subcutaneous fungal infection, which may be caused by a variety of pigmented (dematiaceous) fungi. The infection results from traumatic implantation of the fungus into skin. The disease is usually endemic in warm and humid climates, and follows the same geographic prevalence in India too. We would like to share a case report of chromoblastomycosis from Southern Rajasthan, a non-endemic arid zone of India. The case responded favorably to oral itraconazole.

Case Report

A 32-year-old, apparently healthy male farmer presented to Dermatology Outpatient Department of MB Government Hospital Udaipur with moderately itchy, crusted, slowly progressive lesion over right forearm of 3 years duration. To begin with, the patient noticed a small solid elevated lesion which was non-tender. Similar lesions continued to occur in the vicinity, some of which discharged pus. The lesions coalesced to form a large lesion with a rough whitish surface.

There was no history of grain-like discharge from the lesions. He had been treated for cutaneous tuberculosis for 4 months around 1 year back at a local hospital. However, no improvement was noticed.

On examination, a large irregular verrucous plaque, about 6 inches × 3 inches in size, with hyperpigmented border was present on extensor aspect of right forearm [Figure 1]. Multiple papulonodular satellite lesions were also present. There was associated edema of right forearm. There was no regional lymphadenopathy. The general health of the patient was unaffected. Clinically, differential diagnoses of mycetoma, cutaneous tuberculosis, chromoblastomycosis, and nocardiosis were considered.

Figure 1

Pre-treatment

Routine hematological and biochemical investigations were normal. It was histopathology from a representative lesion, and clinical correlation, which clinched the diagnosis for us. It showed pseudoepitheliomatous hyperplasia, a dense mixed dermal infiltrate of plasma cells, macrophages, PMNs, eosinophils, and giant cells. Numerous copper penny bodies (sclerotic bodies) were seen [Figure 2]. Later, we were also able to demonstrate sclerotic bodies in the KOH smear of skin scraping [Figure 3]. Fungal culture on Sabouraud's dextrose agar showed slowly growing, dark olive-black-colored colonies of Cladosporium carrionii within 4 weeks [Figure 4]. Microscopy showed erect, apically branched, elongate conidiophores producing acropetal chains of smooth-walled conidia [Figure 5].

Figure 2

Chromoblastomycosis histopathology H and E, ×40 showing sclerotic bodies

Figure 3

KOH mount showing sclerotic bodies

Figure 4

Olive green colonies of Cladosporium carrionii

Figure 5

Lactophenol Cotton Blue mount of Cladosporium carrionii

A diagnosis of chromoblastomycosis was made, and the patient was started on itraconazole 100 mg twice daily. The therapy was accepted well and the patient responded favorably. At 1 month of follow-up, the verrucosity of lesions had disappeared, edema reduced, and the nodular lesions had subsided. By the end of 3 months of follow-up, the patient had considerable improvement, with the lesions having been replaced by scar tissue [Figure 6]. We intend to continue the same treatment for another couple of months.

Figure 6

Post-treatment 3 months after follow-up

Discussion

Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissues caused by pigmented or dematiaceous fungi that are implanted into the dermis from the environment.[1] In 1999, Sharma et al. reviewed 30 previous cases, and 4 new cases of chromoblastomycosis from various parts of India.[2] Later, Kumar et al. reported 2 cases in 2000, and Sharma et al. reported 4 cases from Assam in 2010.[34] Pradhan et al. reported 13 cases from Nepal in a retrospective study published in 2007.[5] In a recently published study, Chandran et al. reported 35 new cases from central Kerala.[6] All of these studies concur that chromoblastomycosis is prevalent in warm and humid conditions, which is essential for the growth of these fungi. Such environmental conditions exist primarily in the sub-Himalayan belt, Western and eastern coasts, and southern India,[26] and these regions have been endemic for chromoblastomycosis. Dry climatic conditions do not appear to be favorable for the disease.[2] What brings interest to this case is that this is the probably first case of chromoblastomycosis reported from the northwestern arid zone of India.

The infection can be caused by a number of fungi, but the vast majority is caused by Fonsacaea pedrosoi and Cladosporium carrionii.[1] Fonsacaea pedrosoi appears to be the most common etiological agent worldwide, as well as in cases reported from warm and humid regions of India.[2789] In our case, Cladosporium carrionii was grown on culture. Although overwhelming majority of cases are found on lower limb, slowly progressive verrucous lesions on upper limb should also alert the clinician to the possibility of chromoblastomycosis, as was in our case.

Differential diagnoses include cutaneous tuberculosis and all the deep mycoses, including mycetoma and nocardiosis. Diagnosis is made by demonstration of fungus in the lesions. This is done definitively through culture of causative species on Sabouraud's dextrose agar. However, an easier and more rapid method of diagnosis is bedside demonstration of sclerotic bodies in KOH examination. Sclerotic or muriform bodies are thick-walled single cells or cell clusters seen as brown-colored “copper pennies.” They can also be detected in routine H- and E-stained biopsy specimens.

The therapeutic modalities include itraconazole 200 mg daily, with or without flucytosine (30 mg/kg QID); terbinafine 250 mg daily, and in extensive cases, intravenous amphotericin B. However, the duration of therapy seems to be prolonged and uncertain. Combination therapy with itraconazole and terbinafine has been shown to be synergistic.[5] Cladosporium carrionii seems to respond more rapidly to terbinafine and itraconazole.[10] However, the duration and dose of therapy for complete cure, with no recurrence of lesions, is still to be determined. In our case too, Cladosporium responded to itraconazole; however, we are not sure at what dose and for what duration it needs to be continued to ensure complete cure.

What is new?

Chromoblastomycosis might not be uncommon even in the dry arid regions. Lack of good histopathological facilities at many centers may be the cause of underreporting. Response to itraconazole reinforces the utility of azoles in the disease.