{
  "abstract": "Background and Importance Drug hypersensitivity reactions are a relevant clinical problem as they limit therapeutic options. Patch testing is a key diagnostic tool for delayed cutaneous hypersensitivity (DCH), but its application is limited by the need for individualised preparation, usually compounded in hospital pharmacies. This study aimed to analyse preparation patterns and clinical results of patch tests (PTs).Aim and Objectives To analyse the composition of epicutaneous PTs prepared in the Pharmacy Department for the diagnosis of DCH to drugs.To identify the most frequently requested drugs in order to obtain consumption data and optimise preparation.To evaluate patch test outcomes across therapeutic groups.Material and Methods A 2-year observational, descriptive, and retrospective study (April 2023 – March 2025) in a tertiary hospital.Variables demographics (age and sex), data on prepared PTs (preparation date, drug and ATC therapeutic group), and test results after 96 hours (positive/negative).Data were obtained from pharmacy compounding records and electronic medical records and later analysed using Excel.A descriptive statistical analysis was performed. Categorical variables were expressed as frequencies and percentages, and quantitative variables as measures of central tendency (mean or median depending on the distribution assessed with the Kolmogorov–Smirnov test) and dispersion. The positivity rate was calculated for each ATC group.Results A total of 261 PTs were compounded for 96 patients (58.3% female, mean age 58.9±18.7 years). Drugs belonged mainly to anti-infectives (106), cardiovascular (49), and nervous system (39).Most frequently tested drugs were amoxicillin (14), furosemide (9) and levofloxacin (8). Based on 6-month stability, the estimated number of units needed per semester for these drugs was 4, 3, and 2, respectively.Overall, 21 PTs (8.2%) were positive. The groups with the highest positivity rates were nervous system drugs (20.5%) followed by cardiovascular drugs (14.2%). No drug tested positive more than once.Conclusion and Relevance Compounded patch tests covered a wide range of drugs, mainly anti-infectives and cardiovascular agents, reflecting diverse clinical demand for allergy assessment. Amoxicillin, furosemide, and levofloxacin accounted for nearly one-quarter of preparations.The study helped to estimate the number of units needed per semester to ensure availability without wastage.Although the overall positivity rate was low, nervous system and cardiovascular drugs showed the highest frequency of delayed hypersensitivity.Conflict of Interest No conflict of interest",
  "authors": [
    {
      "affiliations": [
        "Hospital Universitario Ramón Y Cajal- Irycis, Pharmacy Department, Madrid, Spain"
      ],
      "name": "A Martínez-García"
    },
    {
      "affiliations": [
        "Hospital Universitario Ramón Y Cajal- Irycis, Pharmacy Department, Madrid, Spain"
      ],
      "name": "E Gomez-Salazar"
    },
    {
      "affiliations": [
        "Hospital Universitario Ramón Y Cajal- Irycis, Pharmacy Department, Madrid, Spain"
      ],
      "name": "MDR Pintor Recuenco"
    },
    {
      "affiliations": [
        "Hospital Universitario Ramón Y Cajal- Irycis, Pharmacy Department, Madrid, Spain"
      ],
      "name": "C Pérez Menéndez-Conde"
    },
    {
      "affiliations": [
        "Hospital Universitario Ramón Y Cajal- Irycis, Pharmacy Department, Madrid, Spain"
      ],
      "name": "C García-Guijas García"
    },
    {
      "affiliations": [
        "Hospital Universitario Ramón Y Cajal- Irycis, Pharmacy Department, Madrid, Spain"
      ],
      "name": "MA Rodriguez Sagrado"
    },
    {
      "affiliations": [
        "Hospital Universitario Ramón Y Cajal- Irycis, Pharmacy Department, Madrid, Spain"
      ],
      "name": "A Álvarez-Díaz"
    }
  ],
  "title": "3PC-021 Drug allergy diagnosis using epicutaneous patch tests: insights from a 2-year retrospective study",
  "uid": "1c34c909-94cf-5814-b7d4-8c5197f0c034"
}