Patients with positive patch test to formaldehyde can be safely vaccinated with formaldehyde-containing vaccines.

BACKGROUND: Prophylactic vaccination against influenza and other epidemic viruses is recommended for citizens above 65 years. Several vaccines may contain traces of formaldehyde and are contra-indicated in patients hypersensitive (in the broadest possible meaning) to formaldehyde. Thorough knowledge on the various subtypes of hypersensitivity is sparse among non-dermatologists and non-allergists, and therefore many patients are prevented from vaccination based on a positive patch test to formaldehyde. The purpose of this retrospective study was to investigate whether patients with positive patch test to formaldehyde subsequently receiving a formaldehyde-containing vaccine and developed a severe adverse reaction. METHODS/MATERIALS: From January 2000 to June 2021, 169 patients (>50 years) had a positive formaldehyde patch test at the Department of Dermatology and Allergy Center, Odense University Hospital and were included into this retrospective study. The electronic medical record was assessed for receipt of a formaldehyde-containing vaccine after patch test and for subsequent contact with the Acute Ward in the Region of Southern Denmark within 14 days after vaccination. RESULTS: Of the 158 patients residing in the Region of Southern Denmark, 130 patients were vaccinated with one or more formaldehyde-containing vaccines of whom 123 received an influenza vaccine. No contacts to the acute wards were identified. DISCUSSION: Although prospective studies would be beneficial, patients with positive patch test to formaldehyde can be safely vaccinated with formaldehyde-containing vaccines.

Three cases of anaphylaxis following injection of a depot corticosteroid with evidence of IgE sensitization to macrogols rather than the active steroid.

We present three cases with anaphylaxis after injection of a depot corticosteroid. First, the steroid was suspected as the elicitor, but after evaluation the excipient macrogol was found to be the elicitor. One of the patients had reactions to several unrelated drugs. Increased awareness of anaphylaxis to excipients such as macrogols is needed, especially when allergy tests for the active drug is negative and in patients with a history of repeated anaphylaxis to seemingly unrelated drugs. To establish the correct diagnosis it is important to test with the exact formulation of the culprit drug, as well as all the ingredients including excipients.

A randomized, double-blinded, placebo-controlled oral challenge study to evaluate the allergenicity of commercial, food-grade fish gelatin.

BACKGROUND: Recent interest in the labeling of foods and food proteins derived from allergenic sources necessitates determination of the potential allergenicity of such food ingredients. Fish gelatin is extracted from the skin of fish species known to elicit allergic reactions in sensitized individuals. OBJECTIVE: To determine the allergenicity of fish gelatin by double-blinded, placebo-controlled food challenges (DBPCFC) in clinically fish-allergic individuals. METHODS: Thirty fish-allergic patients diagnosed according to the EAACI Guidelines were included (age 9-50 years). Skin prick tests (SPT) and Histamine Release tests (HR) were performed with fish gelatin and codfish, and codfish-specific IgE was measured. All patients underwent DBPCFC with a cumulative dose of 14.61 g fish gelatin. RESULTS: In all 30 patients SPT, HR, and specific IgE to codfish were positive. SPT and HR with fish gelatin were positive in 3/30 and 7/30, respectively. One patient showed mild reaction to placebo and no reaction to the active challenge. Two patients reported mild subjective reactions to active challenge. Upon re-challenge one of them described subjective symptoms again to the active challenge (7.61 g cumulated dose of fish gelatin) with no reaction to placebo, while the other experienced very mild subjective symptoms to placebo and nothing to the active. The proportion of truly sensitive patients was estimated to 0.03 in the total study group. CONCLUSION: None of 30 fish allergic patients reacted adversely to the ingestion of 3.61 g cumulative dose of fish gelatin. In this study fish gelatin presents no risk to fish-allergic patients at the doses typically used. Statistically, these results indicate that there is 95% certainty that 90% of fish-allergic consumers will not react to ingestion of a 3.61 g cumulative dose of fish gelatin.

A comparative study of the allergenic potency of wild-type and glyphosate-tolerant gene-modified soybean cultivars.

A large proportion of soybean cultivars grown in the USA are now genetically modified varieties and concern has been raised about the safety of these products for consumers. A study of the impact on allergenic potency in soybeans, comparable except for the newly introduced gene (CP4 EPSPS), was performed using soybean-sensitized patients. The allergenicity of 18 different (10 GM and 8 WT) soybean extracts was examined blindly by the following three methods: A) Sera from patients with specific IgE against soybean were used to determine concentrations inducing 50% RAST inhibition; B) Histamine release induced by the extracts was examined using blood from sensitized patients; C) SPT was performed on sensitized patients with all 18 extracts. All three methods showed variations in the allergenic potency between the individual extracts but allergenic potential was not affected by presence of the transgene. By using standard in vitro methods and SPT for determination of allergenicity we were not able to detect any significant difference in the allergenic potency between GM and WT soybeans.