Urtikaria/angioedema akibat penggunaan obat anti-inflamasi non-steroid (OAINS) sering dianggap sebagai suatu kasus alergi, meskipun tidak jarang merupakan pseudoalergi. Diagnosis alergi dipikirkan bila reaksi terjadi pada penggunaan OAINS tertentu atau dari golongan sama, sedangkan bila reaksi terhadap OAINS dari golongan berbeda dan bersifat dose dependent maka harus dipikirkan diagnosis pseudoalergi.
      Seorang wanita, usia 22 tahun, tanpa lesi kulit, memiliki riwayat bengkak di wajah dan kemerahan di badan setelah minum obat Bodrex®, parasetamol, atau asam mefenamat. Sebelumnya ia dinyatakan alergi obat. Uji tusuk kulit positif untuk empat alergen hirup dan 17 alergen makanan. Hasil uji provokasi oral (UPO) menggunakan protokol "UPO acetylsalicylic acid (ASA) dua hari buta tunggal" menunjukkan urtikaria dan angioedema berat setelah ASA dosis kedua, maka ditegakkan diagnosis pseudoalergi OAINS.
     Pengetahuan tentang struktur kimia obat merupakan hal yang sangat esensial untuk mendiagnosis alergi atau pseudoalergi terhadap OAINS. Uji diagnostik in vitro lebih aman, tetapi memerlukan fasilitas laboratorium khusus yang sering tidak tersedia di Indonesia. Uji provokasi oral masih menjadi baku emas untuk identifikasi urtikaria/angioedema karena OAINS, namun hal ini harus dikerjakan dengan sangat hati-hati dan ditunjang fasilitas gawat darurat rumah sakit yang memadai. (MDVI 2011; 38/4:171 - 174)

Kata kunci: OAINS, pseudoalergi, uji provokasi oral

       Urticaria/angioedema related to non-steroid anti-inflammatory drugs (NSAID) could be an allergic reaction or drug intolerance (pseudoallergy). Allergic reaction occurs in patient who has been sensitized by drug or drugs similar to NSAID molecular structures (no cross-reactivity), while pseudoallergic reaction is due to ingesting multiple NSAIDs from different molecular structures and is a dose dependent.
      A female, 22 years-old, without skin lesions, presented with a history of angioedema and urticaria after taking drugs (Bodrex®, paracetamol and mefenamic acid). The reaction was diagnosed as multiple drug allergies. Skin prick test was positive forwards four aeroallergens and 17 food allergens. Oral provocation test (OPT) using "OPT acetylsalicylic acid (ASA) singleblind" protocol caused severe angioedema and urticaria after a second dose of ASA, and diagnosis was established as pseudoallergy due to NSAID.
       Drugs chemical structure knowledge are crucial to diagnose allergic or pseudoallergic reaction due to NSAIDS. In vitro diagnostic tests are safer, but need special laboratory facilities which often are unavailable in Indonesia. Oral provocation test remains the only method that can identify NSAID-induced urticaria/angioedema, but needs to be undertaken by a person experienced in medical emergency procedures including resuscitation techniques. (MDVI 2011; 38/4:171 - 174)

Keywords: NSAID, pseudoallergy, oral provocation test