Multiple sinuses from infection of great toe is mainly caused by: September 2007
Ans. B: Actinomycetes Mycetoma is a chronic localized granulomatous inflammatory lesion common in the tropics and sub-tropics. Multiple siAuses, soft tissue swelling and discharge of coloured granules characterize a mycetoma foot. Chronic sinuses discharging granules are caused by (1) Eumycetes (true fungi), (2) Schizomycetes, which includes Actinomycosis (aerobic higher filamentous bacteria) and Botryomycosis (bacterial infection). - Actinomycosis is often caused by Actinomadura or Nocardia species wherein it gains entry after penetrating trauma (splinter, gravel or thorn prick). Young males are commonly affected and 75% of the lesions occur in the lower limbs. The disease slowly progresses from a nodule to multiple sinuses discharging coloured granules. Involvement of bone is late following dermal and soft tissue spread. - Botryomycosis (a misnomer), a chronic suppurative infection is caused by bacteria involving skin or viscera . This rare condition mimics a deep mycotic infection and is often caused by Staphylococcus or Pseudomonas species of bacteria. The feet and hands are commonly affected and penetrating trauma may be a predisposing factor. It usually presents as a nodule, sinus or ulcer, which is initially localized. The diagnosis of actinomycosis is based on clinical findings, demonstration of characteristic granules and culture of the organism from a deep tissue biopsy. Immunological studies (counter immuno electrophoresis and ELISA) are also used. Botryomycosis is diagnosed based on a positive gram's stain and culture; negative fungal cultures and demonstration of the characteristic botryomycotic granules at histopathology from a deep biopsy. In endemic areas, subcutaneous swelling with sinuses should be considered as mycetoma unless proved otherwise. The differential diagnosis includes chronic osteomyelitis, tuberculosis and chronic abscesses.
Tuberculosis
Actinomycetes
Trichosporum
Histoplasmosis