目的 分析复方磺胺甲噁唑（甲氧苄啶+磺胺甲噁唑，trimethoprim-sulfamethoxazole, TMP-SMZ）治疗儿童百日咳诱发皮疹的临床特征，为其在百日咳治疗中的安全用药提供指导。 方法 回顾性纳入2024年1—8月芜湖市第一人民医院238例确诊百日咳并接受TMP-SMZ治疗的患儿，总结皮疹发生率及临床特征。 结果 238例患儿中，34例（14.3%）出现皮疹，其中男性19例（55.9%），5~<10岁占比最高（70.6%，24/34），50.0%（17/34）有过敏性疾病史。皮疹多在服药≥7 d出现（82%，28/34），形态以红色斑疹或斑丘疹为主（97%，33/34），71%（24/34）伴瘙痒。56%（19/34）伴发热，其中77%（10/13）检出鼻病毒、腺病毒等呼吸道病毒。停药后，97%（33/34）皮疹在3 d内消退（41%在1 d内，56%在>1~3 d内）。避光组与非避光组皮疹发生率比较差异无统计学意义（P>0.05）。 结论 TMP-SMZ治疗百日咳易诱发皮疹，5~<10岁儿童高发。皮疹多呈红色斑疹伴瘙痒，半数以上伴发热且多合并病毒感染。绝大多数患儿停药后3 d内皮疹消退，其是否与日光照射相关需进一步验证。

Objective To study the clinical characteristics of rashes induced by trimethoprim-sulfamethoxazole (TMP-SMZ) in children treated for pertussis and to inform safe medication practices. Methods A retrospective analysis was conducted on 238 children diagnosed with pertussis and treated with TMP-SMZ at Wuhu First People's Hospital from January to August 2024. The incidence and clinical features of rashes were summarized. Results Of 238 children, 34 (14.3%) developed rashes; 19 (55.9%) were boys, and the 5 to <10-year age group accounted for the highest proportion (70.6%, 24/34). A history of allergic disease was present in 50.0% (17/34). Rashes typically appeared on or after day 7 of therapy (82%, 28/34) and were predominantly erythematous or maculopapular eruptions (97%, 33/34); 71% (24/34) were pruritic. Fever occurred in 56% (19/34); among those who were tested for respiratory viruses, 77% (10/13) were positive for viruses such as rhinovirus and adenovirus. After discontinuation of TMP-SMZ, rashes resolved within 3 days in 97% (33/34) of patients (41% within 1 day; 56% within more than 1 but within 3 days). There was no significant difference in rash incidence between photoprotection and non-photoprotection groups (P>0.05). Conclusions TMP-SMZ for pertussis can induce rashes, particularly in children aged 5 to <10 years. The eruption is usually a pruritic erythematous or maculopapular rash, with over half of cases accompanied by fever and frequent concomitant viral infections. Most rashes resolve within 3 days after drug withdrawal. The potential association between the rash and sun exposure warrants further investigation.