Refractory Chromoblastomycosis in an Elderly Patient With a Chronic Lesion: Response to Combination Therapy After Multiple Therapeutic Failures

A 70-year-old male patient, a former farmer, with a history of systemic arterial hypertension, type 2 diabetes mellitus, and smoking (40 pack-years), was hospitalized for investigation of a chronic cutaneous lesion present for approximately 30 years. The lesion began on the 4th left toe and later involved the dorsum of the foot and the distal region of the left leg. On physical examination, a crusted plaque with ill-defined borders and hyperkeratotic areas was observed. The patient reported local burning, denying pruritus, pain, or systemic symptoms. Histopathology showed epidermis with pseudoepitheliomatous hyperplasia and compact hyperkeratosis, in addition to neutrophilic microabscesses. The superficial dermis showed a dense chronic inflammatory infiltrate with neutrophils and granuloma formation composed of epithelioid cells and Langhans-type multinucleated giant cells, phagocytosing brown, sclerotic bodies compatible with fungal structures containing melanin pigment—a typical finding of chromoblastomycosis. The patient reported previous treatments without satisfactory clinical response, including: surgical curettage (2020); itraconazole use for 3 years (since 2021); and cryotherapy (2023). During follow-up, sporotrichosis was clinically suspected, and potassium iodide was added, with partial symptomatic improvement. CT scan of the left leg revealed skin thickening on the anterior aspect of the distal leg, medial femorotibial joint space narrowing, and enthesophytes at the quadriceps tendon insertion and at the origin of the patellar ligament. The histopathology report confirmed chronic dermatitis with granulomatous formation, suppurative foci, and brown fungal structures compatible with chromoblastomycosis, with no evidence of malignancy. During hospitalization, the patient was treated with terbinafine 500 mg/day, potassium iodide 10 drops every 12 hours (solution 1000 mg/mL), and itraconazole 200 mg every 12 hours. He evolved with significant clinical improvement and was discharged after 19 days of hospitalization, with outpatient follow-up in infectious diseases and monitoring by the skin committee.