The patient, male, 14 years old, was admitted to the hospital with “a 3-month-old sacrococcygeal skin fracture with yellow fluid flowing for half a month”. The patient’s family complained that 3 months ago, the skin of the sacrococcygeal area was inadvertently found to be broken and fissured, and the patient had been treated at the provincial hospital and our anorectal department and dermatology department successively. Yesterday, he found redness and swelling in the sacrococcygeal region and right buttock, high skin temperature, yellow fluid flowing from the sacrococcygeal fissure, complained of no pain, and fever, body temperature 38.5℃, irregular stool, thin quality, numerous times a day, no voluntary defecation, urine loss, poor sleep, so he came to the clinic again. From 2003 to 2005, he had repeated fractures of the medial epicondyle of the right humerus, fractures of the distal end of the right radius, soft tissue injury of the left elbow and deformity of the right foot and ankle joint, which improved after treatment; since 2005, he had epileptic-like grand mal seizures, which were frequent and irregular, and was now taking medication (details unknown); 4 months ago, he was diagnosed by an outside hospital as “painless sweating syndrome “The repeated treatment was ineffective. Physical examination: T 38.4℃ P 72 times/min R 18 times/min BP 100/58mmhg The child’s mind and spirit are still acceptable, the intellectual development is lower than normal, the development is poor, the nutrition is medium, the passive position, the physical examination is cooperative; the heart and lung and abdominal examination do not show any obvious abnormality; the development of the spinal limbs is still normal, the gait is unstable, the physiological curvature of the spine exists normally, the mobility can be; the left elbow is turned out 45 degrees, the flexion Normal, right elbow thickened, 50 degrees of valgus, flexion and extension can be; normal range of motion of both knees, right knee 0-15 degrees of retroflexion, right foot first metatarsophalangeal joint palmar side of an irregular skin gap, only four toes exist; neurological examination double ankle and knee reflexes were not elicited, pathological reflexes were not elicited. Specialized examination: riding ambulatory position, post-anal sacrococcygeal diffuse swelling about 15×12cm, sacrococcygeal skin fracture size is about 5cm long, there is yellow secretion overflow when pressing the posterior swelling, the secretion has no abnormal odor, the right buttock swelling range is about 20×15cm, there is no pressure pain discomfort when pressing, the skin temperature is higher than normal. Ancillary tests: immunization, stool Rt+OB, chest X-ray showed no abnormalities; coagulation series showed: INR 1.23, PT 15.7sec, PT% 74%, PTR 1.18, APTT 44.8sec, FIB 4.86g/l, TT 14.9sec, fibrinogen clotting time 10.2 g/l, prothrombin time ratio 1.02; blood Rt: WBC 17.8×109/l, NEUT 14.9×109/l, NEUT% 83.5, LYMPH% 11.7, EO% 0.4, HB 100g/l; blood biochemistry: K 2.98 mmol/L, Ca 2.11 mmol/L, TP 59.5 g/l, A/G 0.73; urine Rt: WBC 87.6, RBC 77.4, epithelial cells 17.6, bacterial 10636.5; ECG: sinus bradycardia; sacrococcygeal X-ray: the left ulcer leads to the lower part of the right femoral head with a sinus tract about 30 cm long, the sacrococcygeal ulcer is about 7-8 cm deep, and the contrast agent spreads to the abdominal cavity; sacrococcygeal MRI: it corresponds to the soft tissue of the left parasternal soft tissue at the level of the femoral head in the middle and lower rectum with a size of about 1×1.5 cm bundle-like The abnormal signal, laterally posterior (gas and fluid signal was visible within it), and no abnormal bone morphology signal was seen in the sacrococcygeal region. Discussion: congenital insensitivitv to pain with anhidrosis CIPA, also known as hereditary sensory and autonomic nerve disorder (HSAN) type IV, is an autosomal recessive disorder, a rare disease with low incidence and few cases reported so far in China: Generalized, 80% of patients have complete loss of pain sensation, reduced or absent temperature sensation, prone to burns, and good tactile sensation. Infants and children have self-injurious behavior after tooth eruption. (2) No sweating: no sweating all over the body, dry skin, small chaps on the back of the hands and the ends of the fingers (toes), heavy in winter. Individual patients only have sweat on both sides of the nose or back in summer. (3) Fever: Because of sweating dysfunction, patients have repeated high fever since birth, manifested as flaccid fever or irregular fever, and body temperature is influenced by ambient temperature. About 20% of children die of hyperthermia before the age of 3 years. (4) Mental retardation: psychomotor development is backward, and some children have optic nerve atrophy and cannot see things on both days. (5) Multiple fractures: They are prone to fractures due to the lack of defense response to pain. (6) Joint capsule relaxation: the whole body joint capsule is relaxed, the mobility of each joint exceeds the normal range, joint dislocation often occurs, and the superficial joint capsule is swollen. (7) Infection. Infections are easily caused by frequent biting of fingers, tongue, lips, etc. There may also be a relationship with the patient’s low immune function. There is no cure for congenital painless anhidrosis, but only protective measures to prevent self-harm and trauma, and trauma or ulcers should be treated promptly when they appear; physical cooling should be given when the temperature is high. If the patient’s pain sensation can be partially or fully restored, the prognosis and quality of survival will be greatly improved. The patient had several presentations of fracture, soft tissue injury, and local infection before hospitalization, which were in accordance with the above statement. However, because the initial history of the patient and his family was not very detailed, and because this disease is rare clinically, the clinical doctor was negligent in his consideration, which led the patient to visit outside hospitals and related departments of the hospital several times with little effect. Therefore, clinically, as front-line medical personnel, when examining patients and taking medical history to consider the diagnosis of diseases, they should be as thorough as possible, especially for some recurrent diseases. For this patient, although the diagnosis of painless anhidrosis was clear before he came to the clinic, it is still worth thinking about! In terms of treatment, after the patient was admitted to the hospital, we improved the relevant auxiliary examinations as soon as possible and paid special attention to the diagnosis and differential diagnosis of diseases related to this department. For example, sacrococcygeal X-ray and imaging were performed to understand the condition of sacrococcygeal injury and the depth and course of the sinus tract; sacrococcygeal MRI was performed to exclude the possibility of sacrococcygeal hidden hair sinus. In terms of drug treatment, ceftriaxone 2.0 and tinidazole 100ml were given daily as an anti-infection treatment, and the advantages of combining Chinese and Western medicines in the treatment of anorectal diseases were fully utilized. Gentamicin 160,000 units + saline solution was given daily after stool to flush the wound cavity, and herbal medicine Jiuhua cream and herbal medicine Sangmu Yuhong oil gauze were given to change the medicine after the completion of cleaning. According to the results of sacrococcygeal X-ray, because the sinus tract was deeper and had reached the abdominal cavity, more attention should be paid to the mastery of aseptic operation when changing medicine every day, and because the patient was not very cooperative and did not feel pain when changing medicine at a young age, more attention should be paid to the mastery of the technique when changing medicine to prevent serious complications such as local organ damage and abdominal infection caused by improper operation.