title: Immediate allergic reactions to amoxicillin.
abstract: A large group of patients with suspected allergic reactions to beta-lactam antibiotics was evaluated. A detailed clinical history, together with skin tests, RAST (radioallergosorbent test), and controlled challenge tests, was used to establish whether patients allergic to beta-lactam antibiotics had selective immediate allergic responses to amoxicillin (AX) or were cross-reacting with other penicillin derivatives. Skin tests were performed with benzylpenicilloyl-poly-L-lysine (BPO-PLL), benzylpenicilloate, benzylpenicillin (PG), ampicillin (AMP), and AX. RAST for BPO-PLL and AX-PLL was done. When both skin test and RAST for BPO were negative, single-blind, placebo-controlled challenge tests were done to ensure tolerance of PG or sensitivity to AX. A total of 177 patients were diagnosed as allergic to beta-lactam antibiotics. We selected the 54 (30.5%) cases of immediate AX allergy with good tolerance of PG. Anaphylaxis was seen in 37 patients (69%), the other 17 (31%) having urticaria and/or angioedema. All the patients were skin test negative to BPO; 49 of 51 (96%) were also negative to MDM, and 44 of 46 (96%) to PG. Skin tests with AX were positive in 34 (63%) patients. RAST was positive for AX in 22 patients (41%) and to BPO in just 5 (9%). None of the sera with negative RAST for AX were positive to BPO. Challenge tests with AX were performed in 23 subjects (43%) to establish the diagnosis of immediate allergic reaction to AX, and in 15 cases (28%) both skin test and RAST for AX were negative. PG was well tolerated by all 54 patients. We describe the largest group of AX-allergic patients who have tolerated PG reported so far. Diagnosis of these patients can be achieved only if specific AX-related reagents are employed. Further studies are necessary to determine the exact extent of this problem and to improve the efficacy of diagnostic methods.
authors.affiliation: Allergy Section, Carlos Haya Regional Hospital, Málaga, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Vega
authors.forename: M
authors.initials: M
authors.lastname: Blanca
authors.forename: J J
authors.initials: JJ
authors.lastname: García
authors.forename: M J
authors.initials: MJ
authors.lastname: Carmona
authors.forename: A
authors.initials: A
authors.lastname: Miranda
authors.forename: M
authors.initials: M
authors.lastname: Pérez-Estrada
authors.forename: S
authors.initials: S
authors.lastname: Fernández
authors.forename: J M
authors.initials: JM
authors.lastname: Acebes
authors.forename: S
authors.initials: S
authors.lastname: Terrados
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000009:adverse effects*; D000667:Ampicillin; D000707:Anaphylaxis / Q000139:chemically induced / Q000175:diagnosis / Q000276:immunology; D000799:Angioedema / Q000139:chemically induced / Q000175:diagnosis / Q000276:immunology; D003429:Cross Reactions; D003875:Drug Eruptions / Q000175:diagnosis / Q000209:etiology / Q000276:immunology; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000139:chemically induced* / Q000175:diagnosis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010400:Penicillin G / Q000031:analogs & derivatives; D011852:Radioallergosorbent Test; D012882:Skin Tests; D014581:Urticaria / Q000139:chemically induced / Q000175:diagnosis / Q000276:immunology
chemical_list: D000667:Ampicillin; D000658:Amoxicillin; C030990:benzylpenicilloic acid; D010400:Penicillin G