Mycetoma-like phaeohyphomycosis treated with terbinafine.

Clinical picture

A 70-year-old female patient was referred with a one-year-history of a painful lesion on the plantar surface of her left foot. The slow and had progressive growth limited her ability to walk. Purulent secretion was seen coming out from many draining sinuses. She had had diabetes for two years, and used NPH insulin daily. The patient also had rheumatoid arthritis and was using deflazacort 30 mg/d, chloroquine diphosphate 250 mg/d, sulfasalazine 1 g/d, and paracetamol 1.5 g/d for treatment. She had used methotrexate for one and a half years, until six months ago.

Physical examination revealed erythematous and violaceus confluent nodules with fistulas, of which there was drainage of sanguinopurulent secretion. No grains were observed (Fig. 1). The histological findings were of a chronic and suppurative dermatitis. Black septate ramified hyphae and chlamydospores were seen among neutrophils. PAS stain (Fig. 2) was positive and no grains were observed.

Fig. 1

Mycetoma-like phaeohyphomycosis: lesion in the plantar region.

Fig. 2

Hyphae are seen on PAS coloration (100x).

Purulent exudates were aspirated from a fistula and cultured in an agar-Sabouraud-dextrose medium. Culture showed slow-growing dark brown colonies. Genus and species could not be established. After confirming diagnosis, a 250 mg daily terbinafine was prescribed, for six months, with complete involution of the lesion (Fig. 3). After 36 months, the patient still maintained a clinical cure.

Fig. 3

Healed phaeohyphomycosis: one year after a six-month course of terbinafine.

Phaeohyphomycosis is caused by heterogenous group of dematiaceous fungi and affect immunocompetent and immunocompromised patients [1]. These fungal elements are ubiquitous. Several fungal species have been isolated [2]. There are four clinical manifestations: cutaneous, subcutaneous, systemic and cerebral phaeohyphomycosis. The subcutaneous form is the most common presentation and resembles benign skin and soft tissue neoplasms such as lipoma, sebaceous cysts or neurofibroma [3]. Rarely does it resemble a mycetoma, but no grains are observed clinically or histologically. Histopathological examination plays a major role in diagnosis of phaeohyphomycosis.

Surgical excision is the treatment of choice for cutaneous and subcutaneous infection. We reported a successful treatment with terbinafine.

CRediT authorship contribution statement

Paulo Eduardo Neves Ferreira Velho: Conceptualization, Writing - original draft, Methodology, Writing - review & editing. Marina Rovani Drummond: Writing - original draft, Writing - review & editing. Angelica Zaninelli Schreiber: Conceptualization, Writing - review & editing, Methodology. Maria Letícia Cintra: Conceptualization, Writing - review & editing, Supervision.