A case of rapidly relapsing pyoderma gangrenosum (PG) of the left preauricular area with no undermined borders is described. This might be considered a case of malignant pyoderma (PM), a rare variety of PG. Five months after complete healing obtained with systemic corticosteroids, the preauricular lesion of PG relapsed. As retreatment with oral methylprednisolone induced glucose intolerance and high arterial pressure, sulfa drugs were initially employed with a transitory recovery of the skin lesion. A successive prolonged course with minocycline induced a new complete resolution. To date, at six months' follow-up, the patient is relapse-free. This case confirms that sulfa drugs and minocycline may also be considered alternative therapies in PM. PM is a variety of PG characterized by specific morphological features, a higher tendency to relapse, and poor responsiveness to treatment.