ABSTRACT
BACKGROUND: Penicillin allergy is associated with increased antibiotic resistance and health care costs. However, most patients with self-reported penicillin allergy are not truly allergic. OBJECTIVE: To summarize our experience with allergy tests in patients with a history of penicillin allergy and to compare them with the results of other groups. METHODS: We retrospectively reviewed all patients with a suspected clinical history of penicillin allergy referred to the Drug Allergy Unit at University College London Hospital between March 2013 and June 2015. RESULTS: In total, 84 patients were reviewed. The index drugs included: unidentified penicillin (n = 44), amoxicillin (n = 17), amoxicillin-clavulanic acid (n = 13), flucloxacillin (n = 4), and other penicillins (ampicillin, benzylpenicillin, piperacillin-tazobactam; n = 7). Allergy diagnoses were confirmed in 24 patients (28.6%) (16 to penicillin, 3 to flucloxacillin, 5 to clavulanic acid). Twenty-two patients (91.7%) had allergy diagnosed by positive skin test results. Two patients (8.3%) developed IgE-mediated allergic symptoms during oral challenge (although the skin test results were negative). In vitro specific IgE test results for penicilloyl V, penicilloyl G, and amoxicilloyl were positive in 3 of 16 patients (18.8%). Moreover, reactions to cefuroxime were observed in 3 of 15 patients with penicillin allergy (20%). Selective clavulanic acid and flucloxacillin responders tolerated amoxicillin challenge. The interval between the index reaction and evaluation was shorter (P < .001), and the proportion of patients who could recall the name of the culprit drug was higher (P = .009) in the allergic group. Furthermore, histories of anaphylaxis (33.3%), urticaria, and/or angioedema (58.3%) were more common in the allergic group. Unspecified rashes (35.0%) and nonspecific symptoms (28.3%) predominated in the nonallergic group. CONCLUSION: Only 28.6% of patients with self-reported penicillin allergy were confirmed to be allergic. Importantly, when the index drug is amoxicillin-clavulanic acid or flucloxacillin, the patients may tolerate amoxicillin.
Subject(s)
Anti-Bacterial Agents/adverse effects , Drug Hypersensitivity/diagnosis , Penicillins/adverse effects , Adult , Aged , Anti-Bacterial Agents/immunology , Drug Hypersensitivity/blood , Drug Hypersensitivity/immunology , Female , Humans , Immunoglobulin E/blood , Immunoglobulin E/immunology , Male , Middle Aged , Penicillins/immunology , Self Report , Skin TestsSubject(s)
Adrenal Cortex Hormones/adverse effects , Dexamethasone/adverse effects , Drug Eruptions/etiology , Glucocorticoids/adverse effects , Administration, Oral , Adrenal Cortex Hormones/immunology , Aged, 80 and over , Cross Reactions , Dexamethasone/immunology , Glucocorticoids/immunology , Humans , Intradermal Tests , Male , Patch TestsABSTRACT
BACKGROUND: We report a case of IgE-mediated hypersensitivity to lemon seed. We demonstrate for the first time a pattern of cross-sensitisation between seeds of citrus hybrid species from similar ancestral species origins. CASE REPORT: Described is a case of a 26-year-old female with recurrent anaphylaxis on exposure to lemon seed with sensitisation shown on prick to prick testing. Prick to prick testing was also performed to a variety of citrus fruit seeds and edible foods from additional notable families of the Sapindale order. CONCLUSION: In cases of unexplained or recurrent anaphylaxis in adult patients, citrus seed allergy should be considered.
ABSTRACT
BACKGROUND: Patch testing is the gold standard diagnostic tool for investigating allergic contact dermatitis (ACD). In the United Kingdom, patch testing has been historically confined to the dermatologist's office. Furthermore, detailed studies on patch testing by allergists are significantly underrepresented at the international level. OBJECTIVE: The objective of this study was to undertake a comprehensive evaluation of a patch testing initiative from an allergy practice; we report on various patient characteristics, prevalence and relevance data, in addition to immediate hypersensitivity testing. METHODS: We undertook a retrospective analysis of 156 patients suspected of having contact dermatitis seen in our UK allergy practice between October 2016 and April 2018. RESULTS: Of the 156 patients patch tested (mean age 36.9 years, female 88%, white ethnicity 71.8%, atopy 68.6%), ACD was diagnosed overall in 49% of the cohort and ACD of current relevance was assigned to 31%. Our extended British standard series alone detected the responsible allergen in 87% of patients, and the remaining 13% were detected from supplementary or own material testing alone. Most prevalent contact allergens were nickel (28.2%), p-phenylenediamine (8.3%), cobalt (8.3%), methylisothiazolinone (5.8%), and hydroperoxides of linalool (4.5%) and limonene (4.5%). A history of occupationally related dermatitis (P = .004) and initial (pretest) diagnosis of ACD (P < .001) were both significantly associated with relevant positive patch test reactions (atopy status was not associated P > .05). CONCLUSIONS: ACD was detected in almost 50% of assessed patients, and we highlight the importance of assessing relevance. Hydroperoxides of limonene and linalool are notable additions to the prevalence data. Patch testing should be incorporated into more allergy practices, although availability of training is a limiting factor.