A 65-year-old woman came to see me in the clinic after being referred by a friend. Before she found me, she had visited almost all the major hospitals in Guangzhou, but her disease was still not cured and she was about to lose confidence. It so happened that her child and another patient were colleagues, and during a casual conversation about skin problems, my colleague told me about her visit to me, and that her case was similar, and that she had seen many hospitals, but was not cured, and was finally cured by me. I highly recommend her to come here for a look. When it comes to Guangzhou Chest Hospital, many people have never heard of it, and even if they have heard of it, they only know that it is a specialized hospital for tuberculosis, so how can it have a dermatology department? Even if there is a dermatology department, how can it treat difficult diseases? Back to the grandmother’s skin problem: A year ago, the left ring finger was stabbed by a bone on the lateral edge of the last finger, and then became red, swollen and painful locally. The wounded area was repeatedly crusted, flaking, and progressively enlarged. I have seen both Chinese and Western doctors, and I have taken both Chinese and Western medicines, but I have not been well. I’d say it was serious, but it wasn’t. So it dragged on and on for more than a year. When I saw this, the first disease that popped into my head was swimming pool granuloma. First of all, swimming pool granuloma is a chronic skin granuloma caused by Mycobacterium marinum infection. It is named swimming pool granuloma because it commonly develops after a swimming injury. Clinically it is similar to cutaneous tuberculosis. Elbows, knees, feet, knuckles or fingers are the main sites of involvement, caused by local trauma, and are usually non-itchy and non-painful. This grandmother’s finger was infected after being pricked by a bone while cooking. The examination results suggested that the possibility of Mycobacterium marinum infection was high, so she was given “doxycycline, rifampin, ethambutol” and other drugs for treatment. One month later, the symptoms of the ring finger on the left hand had been significantly reduced. Now the grandmother had confidence. A few suggestions to prevent swimming pool granuloma: 1. When swimming, handling raw meat or live fish, be careful to avoid trauma; 2. When skin injury occurs, immediately stop the above activities, rinse the wound with water, squeeze out a small amount of blood and disinfect the wound with iodophor. Then dress it with sterile gauze block and avoid wet water. 3.It is forbidden to use Band-Aid dressing when the wound is not disinfected. Otherwise, it will easily lead to infection. 4, ordinary small trauma, usually about a week to heal. If the wound is not healed for more than two weeks, promptly go to the hospital for consultation and treatment.