Chemotaxis, random migration, phagocytosis, spontaneous and stimulated NBT reduction were evaluated in neutrophüs from the peripheral blood of 8 patients with acne conglobata and were found to be normal. Only 2 patients had an increased spontaneous NBT reduction, and another exhibited a defect in neutrophil adhesiveness. On this basis, intrinsic defects of the major neutrophil functions, as evaluated in vitro, can be excluded in acne conglobata