Secondary bacterial infection is common. The diagnosis of mycetoma depends on identifying grains. These are obtained using a needle and syringe to extract material from a soft part of the lesion under the skin or by collecting pus. Occasionally a skin biopsy is necessary. Larger white grains or yellow-white grains may be fungal or actinomycotic in origin.
Actinomycotic grains contain very fine filaments.
Fungi grow more quickly than actinomycetes. Treatment Mycetoma does not resolve without active treatment. Actinomycetoma responds well to treatment with appropriate antibiotics but they are required for months or years. The sinuses dry up, swelling and tenderness improves and the grains disappear. Deformity may persist.