Latex-induced anaphylactic reaction in a child with spina bifida

Anaphylaxis to ethylene oxide - a rare and overlooked phenomenon?

Spina bifida patients have been reported to be at increased risk of anaphylactic reactions during general anaesthesia. Following a reaction, latex is often incriminated as spina bifida patients are known to have an increased incidence of latex allergy. Ethylene oxide (EO) has recently been suggested to be an alternative cause, but in many cases reported in the literature, it seems that EO has not been considered as a cause. EO is a highly reactive gas widely used to sterilise heat-sensitive medical devices, and traces of EO can be found in many of the same products as latex. We present the case of a spina bifida patient with a known latex allergy, where EO was found to be the cause of an anaphylactic reaction during general anaesthesia. In addition, we describe measures taken during preparation of a subsequent general anaesthesia to minimise exposure to EO. Spina bifida patients seem to be at increased risk of sensitisation against EO due to repeated exposure, but only limited literature is available. To ensure that EO is considered as a cause in these cases, we recommend that testing for latex and EO go hand in hand following an anaphylactic reaction in this high-risk population.

Peri-operative anaphylaxis

Peri-operative anaphylaxis is an important cause for mortality and morbidity associated with anaesthesia. The true incidence is unknown and is most likely under reported. Diagnosis can be difficult, particularly as a number of drugs are given simultaneously and any of these agents can potentially cause anaphylaxis. This review covers the clinical features, differential diagnosis and management of anaphylaxis associated with anaesthesia. The investigations to confirm the clinical suspicion of anaphylaxis and further tests to identify the likely drug(s) are examined. Finally the salient features of common and rare causes including non-drug substances are described.

Sensitivity and specificity of different skin prick tests with latex extracts in pediatric patients with suspected natural rubber latex allergy--a cohort study

Skin prick tests (SPT) with latex extracts are commonly used in the diagnostic approach of natural rubber latex (NRL) allergy. Non-ammoniated latex extracts are commonly utilized for this purpose. There is only one commercially available ammoniated latex extract for both diagnostic and therapeutic purposes. To our knowledge, no direct clinical comparisons have been made so far comparing sensitivity and specificity of different latex extracts in patients with clinically confirmed latex allergy. The objective of this study was to evaluate sensitivity and specificity of non-ammoniated or ammoniated SPT of latex extracts in children with a clinical history suggestive of NRL allergy. Forty-two subjects (age 4-15 yr), referred to our Allergy Clinic Center, with suspected clinical signs of NRL allergy were evaluated. Patients were selected according to the following inclusion criteria: pediatric patients of age above 4 yr with a suspected clinical history of urticaria, rhinoconjunctivitis and/or asthma due to sensitization to NRL. A definitive NRL allergy diagnosis was made on the identification of latex-specific IgE (>0.7 kU/l), positive glove use test and a highly indicative clinical history. NRL allergy was confirmed in 26 (62%) subjects. SPT for latex were performed with three different SPT solutions containing non-ammoniated NRL extracts (product A: Lofarma SpA, Milan, Italy and product B: Stallergenes, Milan, Italy) or an ammoniated extract (product C: ALK-Abellò, Madrid, Spain). A positive result was considered as the appearance of a wheal with a diameter >3 mm. In patients with confirmed NRL allergy, wheal mean (s.d.) diameters were 7.3 (2.1) with product C, and 5.7 (2.3) and 4.4 (1.8) with products B and A respectively (p = 0.004 C vs. B and A). Mean wheal diameters were significantly higher for product C in comparison with product B and A (p < 0.04). Sensitivity according to the different products tested was 65% (product A); 81% (product B) and 96% (product C) (p = 0.0084; C vs. A). No difference between the three products was observed regarding diagnostic specificity (94%, 88% and 94%, product A, B and C, respectively). Our study shows that diagnostic sensitivity of different latex extract for SPT could differ. In this particular clinical setting (i.e., children with NRL allergy) ammoniated latex extract shows a higher sensitivity in comparison with non-ammoniated products. This aspect should be considered in the diagnostic approach in subjects with suspected NRL allergy. In children with clinical confirmed latex allergy, sensitivity and specificity of different commercially available skin prick test could vary. Ammoniated latex extract has shown a higher sensibility in comparison with non-ammoniated products.