A 43-year-old male patient was diagnosed with acute sinistral pleuropneumonia and a pronounced thoracic pain syndrome. Despite of his painful ailments the patient refused antibiotic treatment. A complementary therapy comprising physiotherapy, hydrotherapy, herbal therapy and vitamin C, cupping and QiGong was initiated. A cantharidin blister was applied topically to the left thorax in order to treat the pain syndrome. The multimodal CAM treatment resulted in a rapid clinical and x-ray resolution of pneumonia, and cantharidin treatment effectively relieved pain. The case and the potential of topical cantharidin in pain syndromes are discussed.