The Gorgas Courses in Clinical Tropical Medicine

Selected Cases Seen by 2007 Course Participants

Discussion: White draining granular material grew Phaeoacremonium inflatipes.  Culture for bacteria was negative.  Excisional biopsy or invasive cultures of the sinus tracts are not usually necessary for diagnosis of madura foot as the granules usually come to the surface even if not on a daily basis.  The main and important differential diagnoses in this case are TB, botrymycosis (chronic staphylococcal infection) [see 2003 Case #4], actinomycosis [see 2001 Case #9], other causes of chronic bacterial osteomyelitis, and malignancy.  Madura foot is a common subcutaneous mycosis in the tropics and is caused by a wide variety of fungal organism.

Madura foot typically presents in a similar way to this patient, with a small local tumor slowly progressing over years to more widespread destruction of subcutaneous tissue and bone while sparing nerve and vasculature.  Etiologic agents of maduramycosis are divided into several groups:

1. The eumycetomas are typically caused by Madurella mycetomatis (by far the most common cause of Madura foot in Peru; produces dark granules), Exophilia sp. and Pyrenochaeta sp., as well as Fusarium and Acremonium (produce pale granules).
2. Other subcutaneous mycoses including phaeohyphomycosis (Phaeoacremonium sp, Loboa loboa), sporotrichosis and chromomycosis.
3. Actinomadura madurae, Nocardia brasiliensis, and Streptomyces somaliensis produce smaller white, yellow, or brownish granules

Mycetomas appear to be localized phenomena due to local inoculation without any potential for widespread dissemination.

Maduramycosis is most common in Africa, Central and South America, and the Far East.  Most cases occur in tropical latitudes between 15 degrees South and 30 degrees North in humid moist environments.  The organisms have been isolated from soil as well as from plant thorns.

The identification of species of Phaeoacremonium based on their morphological and cultural characters is difficult [see detailed review in J Clin Microbiol. 2005 Apr;43(4):1752-67], as is evident from the numerous incorrect identifications that have been made since the genus was established in 1996.  A reliable technique for Phaeoacremonium species identification is needed.  At present 6 species have been associated with human disease but reports in the literature are scanty.

In contrast to bacteria and actinomycosis (which is responsive to Penicillin), madura foot has been characterized as being poorly responsive to medical therapy, and aggressive surgery or amputation is commonly recommended.  Although randomized controlled trials are not available, recent consensus from experts in highly endemic areas of Africa and the Americas indicates that 6-12 months of ketoconazole or itraconazole is very often successful in improving the lesions, even if complete cure is not achieved.  In tropical countries, amputation or highly destructive excisional procedures in impoverished rural residents usually carriers a poor prognosis for rehabilitation and ongoing complications.  Prosethetic appliances are not available.  Because the infection does not disseminate and is non-painful, surgery should be used only as a last resort with widespread disease, weighing the benefits versus the above-mentioned adverse aspects of this kind of surgery in certain settings.  Less than extensive disease can often be observed for several years even if drug therapy is not available.

Our patient has received itraconazole 200 mg/d for 1 year with some improvement [Image E].

History:  34-yo male with a 4-month history of painful swelling of the right foot, multiple draining papular lesions [Images A, B].  The fluid was gritty and bloody without purulence.  No history of trauma, no similar history in contacts or colleagues, no fever or chills.  Diabetic on metformin.

Epidemiology:  Fisherman, born in Chincha (250 km south of Lima) but resident in Lima for more than 13 years.  Frequent sea trips all along the north shore of Peru.

Physical Examination:  Afebrile.  Right foot as shown.

Laboratory Examination:  CBC and biochemistry were normal.  Chest x-ray was normal.  MRI of the right foot [Images C, D] showed an infiltrative lesion limited to subcutaneous tissue without any bony destruction or subluxation of small bones of the ankle.