患者，女，43岁，青海玉树人。2022年9月因“间断胸背部疼痛不适4月余”就诊于青海大学附属医院呼吸科。入院查体：前胸部、右上肢肘关节上、左下肢膝关节等处可触及约1 cm × 0.5 cm皮下结节，压痛明显。血常规示：嗜酸粒细胞计数15.58 × 10⁹/L，嗜酸粒细胞比67.4%，血沉17.00 mm/h。骨髓检查结果示：骨髓造血组织增生活跃，嗜酸粒细胞明显增多，约占有核细胞的62%。皮肤活检病理见血管周及脂肪小叶间灶状淋巴细胞、浆细胞及嗜酸粒细胞浸润。给予醋酸泼尼松片（60 mg/d）口服治疗1个月，皮下结节疼痛未缓解。2022年11月自患者左耳后、右下肢、左上肢、颈部、前胸部等处皮下相继共钻出5只蝇蛆幼虫，经形态学鉴定为牛皮蝇幼虫。患者为牧民，长期居住于高原牧区，夏天有席草地睡眠和草地晾晒衣物经历。结合患者流行病学调查、临床表现和相关检查结果，最终诊断为皮肤蝇蛆病继发性嗜酸粒细胞增多。确诊后予阿苯达唑片（0.4 g/d）和氯雷他定片（10 mg/d）口服治疗13 d。复查血常规示嗜酸粒细胞恢复正常，患者症状好转。电话随访1年，患者未再出现皮肤疼痛及其他不适。

A 43-year-old female patient from Yushu, Qinghai, presented to the respiratory department of the Affiliated Hospital of Qinghai University due to “intermittent chest and back pain discomfort for more than 4 months” In September 2022. Physical examination upon admission revealed subcutaneous nodules approximately 1 cm × 0.5 cm in size, palpable on the anterior chest, above the right upper limb elbow joint, and on the left lower limb knee joint, with significant tenderness. Blood test showed an eosinophil count of 15.58 × 10⁹/L, an eosinophil percentage of 67.4% and an erythrocyte sedimentation rate of 17.00 mm/h. Bone marrow examination results indicated active hematopoietic tissue proliferation in the bone marrow, with a significant increase in eosinophils, accounting for approximately 62% of nucleated cells. Skin biopsy pathology revealed focal lymphocyte, plasma cell, and eosinophil infiltration around blood vessels and between adipose lobules. Treatment with oral prednisone acetate tablets (60 mg/d) for one month did not alleviate the pain in the subcutaneous nodules. In November 2022, a total of 5 fly larvae emerged successively from subcutaneous sites on the patient’s left ear, right lower limb, left upper limb, neck and anterior chest. Morphological identification confirmed them as Hypoderma bovis larvae. The patient is a herdsman residing in a plateau pastoral area for a long time, with a history of sleeping on grass and drying clothes on the grass during summer. Based on the epidemiological investigation, clinical manifestations, and relevant examination results, the final diagnosis was secondary eosinophilia due to cutaneous myiasis caused by H. bovis larvae. After confirmation of the diagnosis, the patient was treated with oral albendazole (0.4 g/d) and loratadine tablets (10 mg/d) for 13 days. A follow-up blood test showed that the eosinophil count returned to normal, and the patient’s symptoms improved. During a one-year telephone follow-up, the patient did not report any recurrence of skin pain or other discomfort.