Case report

A 57-year-old male farmer presented a pruritic lesion on the left auricle, with 20 years of evolution. He did not recall local trauma at the onset of the condition. Upon examination, an infiltrated, erythematosquamous lesion was observed on the left ear. The histopathological examination presented a granulomatous inflammatory infiltrate with suppurative foci (Fig. 1A and B).

Figure 1 (A and B) Erythematous, infiltrative lesion in the left ear. Histopathological examination: granulomatous inflammatory infiltrate with suppurative foci (Hematoxylin & eosin, ×400). 

What is your diagnosis?

The review of the sections for histopathological examination evidenced the presence of fumagoid bodies, compatible with chromoblastomycosis.

In the direct examination of biopsy fragments in 20% KOH, septate demaceous hyphae and isolated yeast cells in pairs were observed, as well as some gemmule structures. In culture, on Mycosel agar (DIFCO®) and Sabouraud dextrose agar (DIFCO®) with chloramphenicol (0.05 g/L), a blackened colony growth was observed; in microculture, phenotypic findings compatible with Rhinocladiella sp. were observed (Fig. 2 A and B).

Figure 2 (A and B) Direct examination: fumagoid bodies. Microculture: septate demaceous hyphae and elliptical conidia in the upper portion of simple or slightly branched conidiophores - phenotypic characteristics compatible with Rhinocladiella spp. (KOH-20%, ×400; blue, lactophenol, ×400). 

R. aquaspersa was confirmed through amplification and sequencing of the intergenic spacer (ITS) region of the ribosomal DNA (rDNA) using the polymerase chain reaction (PCR) technique.

After confirmation of the diagnosis of chromoblastomycosis, itraconazole (300 mg/day) was initiated; the patient presented significant improvement after 25 days and almost complete remission in ten weeks (Fig. 3 A and B). The patient remains under outpatient follow-up.

Figure 3 (A and B) After 25 days of treatment, and at the end of ten weeks. 

Discussion

Chromoblastomycosis is a subcutaneous mycosis caused by demaceous fungi of the order Chaetothyriales, family Herpotrichiellaceae, found in decomposing soil, vegetables, plants, and wood.^1,2 The main etiological agents are from the genera Fonsecaea, Cladophialophora, Phialophora, Rhinocladiella, and Exophiala. Inoculation occurs after trauma with contaminated material.^1,3,4

The condition most frequently affects men between 40 and 50 years of age, being considered a cosmopolitan disease, with greater prevalence in tropical and subtropical regions.² In Brazil, it occurs in most states, with a predominance in the Amazon region, particularly in the state of Pará.^2,5

The disease mainly affects the lower limbs. In cases with long evolution, association with lymphedema is common.^1,4,6 In Japan, the most common locations involved are the upper limbs, face, and cervical region.² Reports of manifestations exclusively on the auricle are rare.^1,3,6-10 Among the cases reported in this topography, Fonsecaea pedrosoi^1,3,10 and Phialophora verrucosa⁷ were the most commonly identified agents, followed by Fonsecaea nubica⁶ and Rhinocladiella aquaspersa.⁸

According to the literature consulted, this is the second case with isolated involvement of the auricle caused by R. aquaspersa.

In the Amazon region, the differential diagnosis must include Jorge Lobo's disease, leprosy, anergic leishmaniasis, cutaneous tuberculosis, and paracoccidioidomycosis. Histopathological and mycological exams are essential for diagnosis.

Several treatments are indicated for chromoblastomycosis. For localized lesions, surgical excision, cryotherapy, or thermotherapy are recommended; for more extensive cases, systemic and immunoadjuvant antifungals are recommended.^2,4 Among systemic antifungals, itraconazole, posaconazole, voriconazole, and isavuconazole are used.⁴ The literature reports two cases of chromoblastomycosis in auricular locations, which presented complete regression after treatment with flucytosine³ and itraconazole¹ for 12 and 10 weeks, respectively.

There are reports of a good therapeutic response with the association of systemic antifungals and topical immunoadjuvants, such as imiquimod.⁴