Background Drug-induced hypersensitivity syndrome (DIHS) is a severe, potentially life-threatening adverse drug reaction marked by a prolonged latency period and frequent relapses, posing significant challenges for early clinical recognition.

Objective To analyze the clinical characteristics, distribution of culprit drugs, laboratory abnormalities, and prognostic factors in patients with drug-induced hypersensitivity syndrome (DIHS), so as to provide evidence for early clinical identification and treatment.

Methods Clinical data were collected from patients with DIHS who were hospitalized in the Department of Dermatology, the First Medical Center of PLA General Hospital from January 2015 to December 2025. Patients with a RegiSCAR score > 5 were defined as confirmed cases. The demographic characteristics, culprit drugs, clinical manifestations, laboratory findings, treatment, and outcomes of the patients were analyzed.

Results A total of 34 patients diagnosed with DIHS were enrolled in this study, including 16 males and 18 females, with a mean age of (43.6±16.5) years. Most patients (76.5%) were aged between 30 and 55 years. The incubation period of the disease ranged from 2 to 60 days, with a median of 21 (IQR: 11 - 30) d. In terms of clinical manifestations, aside from skin rash, liver function impairment had an extremely high incidence (28 cases, 82.4%). The main causative sensitizing drugs included antibacterial agents (12 cases, 35.3%), traditional Chinese medicine (7 cases, 20.6%), anti-gout drugs (5 cases, 14.7%), and anti-epileptic drugs (4 cases, 11.8%), antipyretic and analgesic agents in 2 cases (5.9%), antidepressant medications in 2 cases (5.9%), additionally, 1 case was induced by an immunosuppressant and 1 case by a biological agent. Laboratory examinations revealed leukocytosis in 24 cases (70.6%) and eosinophilia in 17 cases (50.0%). Concomitant viral or pathogen infections were detected as follows: cytomegalovirus infection in 14 cases (41.2%), herpes simplex virus infection in 12 cases (35.3%), Epstein-Barr virus positive infection in 11 cases (32.4%), rubella virus positive infection in 9 cases (26.5%), Coxsackievirus positive in 1 case (2.9%), and mycoplasma pneumoniae positive in 4 cases (11.8%). All patients received glucocorticoid therapy, and nearly half (16 cases, 47.1%) received combined treatment with intravenous immunoglobulin. All 34 patients achieved short-term clinical remission after treatment, with an overall response rate of 100%; during long-term follow-up, 27 cases (79.4%) were cured and 7 cases (20.6%) experienced recurrence. The incubation period of the recurrence group was significantly longer than that of the non-recurrence group (34.9±19.0 d vs 20.2±11.4 d, P=0.015).

Conclusion DIHS cases in our center are characterized by a relatively long latency period. Antibacterials and traditional Chinese herbal medicines are the predominant culprit drugs, and liver function impairment is common. Early recognition, prompt withdrawal of the offending drug, and administration of systemic corticosteroids yield definite therapeutic efficacy. Viral infections may be associated with disease relapse, although the value of antiviral therapy remains to be validated.