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Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Report
  5. Discussion
  6. References

We report a 21-year-old farmer with a 4-year history of a nodular plaque with fistulas and induration of adjacent skin. The lesion had been treated surgically at another hospital, but recurred 2 years later.

Black, charcoal-like grains were observed draining through the fistulas. A biopsy specimen showed brown grains with filaments in an abscess surrounded by macrophages, giant cells, and lymphocytes. Culture demonstrated small white colonies of Madurella mycetomatis. The patient was treated with itraconazole for 6 months, followed by surgery. TNP was initiated in the immediate post-operative period, and copious granulation tissue was observed within 1 week. Autologous skin grafting was performed, and itraconazole was continued for an additional 3 months. Although necrosis of the graft ensued, the functional result was acceptable. The patient appeared free of disease at 18 months of follow-up.

Eumycotic mycetoma is an infectious and inflammatory process that occurs after traumatic inoculation of fungi through the skin. Surgery is the treatment of choice, but successful reconstruction may be challenging and recurrence is common. Topical negative pressure (TNP) promotes the formation of granulation tissue, which facilitates closure of deep wounds and chronic ulcers. This case illustrates that eumycotic mycetoma is difficult to treat. Whether TNP contributed to the successful outcome cannot be proven but, given the generally poor response of eumycetoma to therapy, we suggest that the role of TNP in the management of this disease merits attention.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Report
  5. Discussion
  6. References

Eumycotic mycetoma (eumycetoma) is an infectious and inflammatory process that occurs after the traumatic inoculation of fungi through the skin. It is more common in farmers and outdoor workers. In Latin America, the use of open shoes or the habit of going barefoot while working in the fields favors frequent trauma to the feet and legs. India and Sudan have the highest incidence of eumycetoma. In Mexico, only two percent of mycetomas are caused by fungi, whereas 98% are a result of actinomycetes (actinomycetoma); 1.2% of eumycetomas are caused by black fungi (dark grains) and 0.2% by white fungi (pale grains).1,2 The most common pathogenic eumycetoma species in Mexico is Madurella mycetomatis. Topical negative pressure (TNP) devices have been used recently for the management of chronic wounds and diabetic feet, with variable results.3,4 This procedure promotes a decrease in edema and enhances granulation tissue formation,5 which prepares the wound bed for subsequent surgery. TNP therapy is applied to open wounds with a sponge attached to a plastic tube through which constant negative pressure is maintained and regulated, depending on the quantity of exudate. The entire sponge must be covered with an adhesive film to ensure hermetic closure.

Case Report

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Report
  5. Discussion
  6. References

A 21-year-old farmer was referred with a 4-year history of a nodular plaque involving the arch of the plantar surface of the right foot, which developed after trauma to the foot while working in the fields. The patient had been treated surgically in his community, but developed scarring and recurrence within 6 months. The lesion contained fistulas that drained bloody serous exudate and black charcoal-like granules or grains. Physical examination demonstrated a nodular plaque with fistulas and scarring (Fig. 1). On direct examination with Lugol's iodine, grains were observed. A biopsy specimen obtained from the deep dermis near to one of the fistulas showed the characteristic black–brown grains, with thick filaments at the periphery, in the middle of a suppurative granuloma containing neutrophils, fibrous stroma, and Langerhans-type giant cells. Gomori–Grocott and periodic acid–Schiff (PAS) stains demonstrated fungi (Fig. 2). Cultures of the grains on Sabouraud's and Mycosel agar were positive for Madurella mycetomatis with the typical diffusing pigment.

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Figure 1. Clinical presentation with fistulas and scarring

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Figure 2. Periodic acid–Schiff (PAS)-stained section demonstrates that the grains contain broad hyphae and vesicles (×40)

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X-Ray and computed tomography scan showed that only soft tissue, not bone, was affected.

Treatment with oral itraconazole, 300 mg daily for 6 months, was associated with only a mild decrease in inflammation and partial closure of the fistulae. Therefore, surgical removal with a wide margin around the excision site was performed (Fig. 3). TNP therapy was administered for 1 week postoperatively to stimulate granulation tissue formation (Fig. 4), followed by autologous skin grafting. Although the graft developed necrosis, the final functional result was acceptable, with complete re-epithelialization of the area. Itraconazole was continued for an additional 3 months, and the patient was free of disease at 18 months of follow-up. The final outcome of the scar was acceptable aesthetically and functionally; the patient reported only slight dysesthesia during ambulation because of scarring at the plantar arch.

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Figure 3. Macroscopic appearance of the grains in the surgical specimen

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Figure 4. Granulation tissue after 1 week of topical negative pressure (TNP) therapy

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Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Report
  5. Discussion
  6. References

The treatment of eumycetoma is a major challenge. One of the most common problems is that affected patients are farmers or other outdoor laborers who often lack the education and economic resources to obtain prompt medical evaluation, resulting in a considerable delay in treatment. Even when early diagnosis is made, patients usually cannot afford treatment. The final outcome is potentially severe functional impairment and even amputation of the affected limb. Surgical treatment may be the only option, especially if the lesion is well defined. Surgery in combination with azole treatment is the recommended regimen for small eumycetomas of the extremities, as reported in other countries with a high incidence of mycetoma.6 Anecdotal reports suggest that voriconazole is a good option for black grain mycetoma, but our patient could not afford this drug.7 Itraconazole helped to stabilize his lesion prior to surgical excision with a wide margin. Continuation of itraconazole for 3 months postoperatively may have helped to reduce the risk of recurrence.

TNP therapy has been used previously in many types of chronic wounds with good results.3–5 Although our patient's graft did not survive, the presence of adequate granulation tissue in the surgically treated area facilitated re-epithelialization of the wound. To our knowledge, this is the first report of TNP in a treatment regimen for eumycotic mycetoma that was associated with a satisfactory clinical and functional result. Indeed, TNP may have contributed to the successful outcome in our patient.

The pathogenesis of mycetoma is incompletely understood, but the failure of active mobilization of an effective early phagocytic response has been cited as a possible reason for fungal survival for a sufficient time for grains to develop.8 TNP may enhance the inflammatory response and thus ensure death of any residual fungal elements. Therefore, early diagnosis and prompt intervention with antimycotics and/or surgery may eliminate the need for aggressive surgical treatment and amputation.9,10

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Report
  5. Discussion
  6. References