title: Fixed Drug Eruption Due to Selective Hypersensitivity to Naproxen with Tolerance to other Propionic Acid NSAIDs.
abstract: BACKGROUND
  Naproxen is a non-steroidal anti-inflammatory drug (NSAID), belonging to propionic acid group, and its chemical structure is a 6-metoxi-metil-2-naftalenoacetic acid. Fixed drug eruptions (FDE) have been rarely reported.
  
  
  OBJECTIVE
  A 38-year-old woman referred that after 2 hours of taking 2 tablets of naproxen for a headache, she developed several edematous and dusky-red macules, one on right forearm and the other two in both thighs and she was diagnosed with FDE probably due to naproxen.
  
  
  METHODS
  We performed patch testing (PT) (Nonweven Patch Test Strips Curatest® Lohman & Rauscher International, Rangsdorf, Germany), with ibuprofen (5% Petrolatum), ketoprofen (2.5% Petrolatum), naproxen and nabumetone (both 10% in DMSO) on the residual lesion of the forearm with naproxen and in both thighs with ibuprofen, ketoprofen and nabumetone.
  
  
  RESULTS
  Readings at day 1 (D1) and day 2 (D2) showed negative results to ibuprofen, ketoprofen and nabumetone, but were positive to naproxen in D1. A single blind oral challenge test (SBOCT) with other propionic acid derivates were performed in order to check for crossreactivity between them: ibuprofen, ketoprofen and nabumetone were administered and all drugs were well tolerated.
  
  
  CONCLUSIONS
  In our patient PT confirmed the diagnosis and allowed us to study the cross-reactivity between NSAIDs of the same group, and confirmed by SBOCT. Cross-reactivity between propionic acid derivatives was studied. This is a case of hypersensitivity to naproxen with good tolerance to other propionic acids NSAIDs (ibuprofen and ketoprofen) and nabumetone, confirmed by PT and SBOCT. Some relavent patents for fixed drug eruption are discussed.
authors.affiliation: Hospital General Universitario Gregorio Marañón. Allergy Department, 46 th Doctor Esquerdo Avenue, 28007 Madrid, Spain. blancanoguerado@gmail.com.
authors.forename: Blanca
authors.initials: B
authors.lastname: Noguerado-Mellado
authors.forename: Abdonias R
authors.initials: AR
authors.lastname: Gamboa
authors.forename: Patricia R
authors.initials: PR
authors.lastname: Perez-Ezquerra
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Cabeza
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Fernandez
authors.forename: Manuel
authors.initials: M
authors.lastname: De Barrio Fernandez
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D003429:Cross Reactions; D003875:Drug Eruptions / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006261:Headache / Q000188:drug therapy*; D006801:Humans; D009288:Naproxen / Q000009:adverse effects*; D010328:Patch Tests; D010330:Patents as Topic; D011237:Predictive Value of Tests
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D009288:Naproxen