* 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.

Penicillin Allergy: Value of Including Amoxicillin as a Determinant in Penicillin Skin Testing

“…This finding contrasts with those of Vega et al [19], who found that 63% of their cohort were positive to amoxicillin on PST. This large discrepancy may be due to differences in prescribing patterns, as the study performed by Vega et al [19] was conducted in Spain, where there is a higher rate of prescriptions (up to 45%) given for amoxicillin [16]. Sastre et al [29] reported that 21% of their patients were allergic to amoxicillin but demonstrated good tolerance to penicillin.…”

“…These results suggest that the acyl side chain may be a significant antigenic determinant apart from the penicillin nucleus [15,16,18]. Vega et al [19] described a group of patients with suspected beta-lactam allergy who demonstrated allergic reactions only to amoxicillin (30.5%), while tolerating penicillin. Of these individuals, 63% were positive for amoxicillin on skin testing and 22% were positive on a radioallergosorbent test [19].…”

“…Vega et al [19] described a group of patients with suspected beta-lactam allergy who demonstrated allergic reactions only to amoxicillin (30.5%), while tolerating penicillin. Of these individuals, 63% were positive for amoxicillin on skin testing and 22% were positive on a radioallergosorbent test [19]. These studies suggest that amoxicillin may represent an important antigen to include in a PST panel.…”

Comparison of two basophil activation markers CD63 and CD203c in the diagnosis of amoxicillin allergy

“…Cross-reactivities between different families of BL are known, but they are not as frequent as was previously supposed [10,11]. In a series of patients with a positive ST to amoxicillin (AX), 43% also reacted to ampicillin (AMP), but only 9% reacted to benzylpenicilloyl-poly-L-lysine and 9% to MDM [12].…”

Amoxicillin in the Aquatic Environment, Its Fate and Environmental Risk

“…Currently, the widely prescribed β-lactam antibiotics are among the drugs most frequently eliciting allergic reactions in human populations [105][106][107][108].…”