A woman with chronic subcutaneous swelling of the right foot associated with sinus tracts discharging yellow grains.

A 41-year-old female from Mexico living in the United States over the past 7 years presented with a 4-month history of slowly progressive painless subcutaneous swelling and deformity on the anteromedial aspect of her right foot with multiple sinus tracts with intermittent serosanguineous drainage mixed with yellow grains (Figure 1). She reported the occurrence of a similar episode in the same affected area 13 years prior. At that point, she was treated with an unknown combination of two oral antibiotics for a 3-year period that resulted in significant clinical improvement. Prior to coming to the US, she lived in an impoverished rural area of Guanajuato, Mexico. Since early childhood, she had participated in farming activities, and was often barefoot due to a lack of shoes. She denied any associated systemic symptoms such as fever, weight loss, or malaise. As the swelling progressively increased, she developed difficulty walking.