Mycetoma or Madura foot is a chronic specific inflammatory condition caused by the Actinomyces madurce. This organism closely resembles the A. bovis, but the club-shaped extremities are absent and spores may occur along the threads. Can be grown artificially; stains by the ordinary methods and by Gram's.

Usually attacks but one foot, particularly the great toe, but may involve the leg, arm, or hand. A nodule slowly appears, and in the course of a year or two may soften and discharge a thin pus in which are found minute rounded bodies resembling fish-roe. These bodies may be either pinkish in color, the pale, or ochroid variety, or black like gunpowder, the tnelanoid form.

Fig. 35. - Actinomyces of Madura Foot (Wright and Brown).

Granule crushed beneath a cover-glass, showing radial striations in the hyaline masses. Preparation not stained; low magnifying power.

On account of the degeneration numerous sinuses may form. The disease is painless and seldom fatal.