title: [Desensitization protocol to methotrexate. Clinical case].
abstract: Methotrexate (MTX) is a folic acid antagonist; its main effects are immunosuppressive and antineoplastic. It is used in the treatment of malignancies, lung and rheumatic diseases. There are few reports of immediate hypersensitivity and these include anaphylaxis, urticaria and angioedema. We present a 17 years old male, with a history of anaphylaxis to methotrexate during the induction therapy of ALL L2. It was decided that the drug was necessary for the patientís survival, thus diagnostic skin testing was performed, during which he presented anaphylaxis. The desensitization consisted of 5 days premedication and a 12-steps protocol of intravenous infusions of 8 hoursí duration, starting with a 1:1.000.000 dilution. The patient was successfully desensitized. He was maintained with IV MTX 50mg/m2 weekly for 1 year using the same protocol successfully. This protocol of 12 steps was successful and safe to desensitize a patient with anaphylaxis due to MTX. During such protocol intensive care supervision is critical, as all precautions should be taken to avoid endangering the life of the patient.
authors.affiliation: Servicio de Alergia e InmunologÌa ClÌnica, Hospital Infantil de MÈxico Federico GÛmez, MÈxico D.F. jmaya01@yahoo.com.mx.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Maya-Epelstein
authors.forename: Alexander
authors.initials: A
authors.lastname: Morales
authors.forename: Blanca
authors.initials: B
authors.lastname: Del-Rio-Navarro
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Rosas-Vargas
mesh_terms: D000707:Anaphylaxis; D003888:Desensitization, Immunologic; D004342:Drug Hypersensitivity; D005493:Folic Acid Antagonists; D006801:Humans; D008727:Methotrexate; D014581:Urticaria
chemical_list: D005493:Folic Acid Antagonists; D008727:Methotrexate