Dasanayake D, Karunatilake C, Karunaratne C, Fernando N, Iddagoda J, et al.
BMC immunology •
Alpha gal syndrome (AGS) is a delayed allergy to red meat, due to IgE to galactose-alpha-1,3-galactose (alpha-gal). Sensitization occurs via tick bites. It has been described in the US, Europe, Australia, Japan and South Korea, but reports from the Indian subcontinent are rare. We report the demographics of alpha-gal allergy for the first time from the Indian subcontinent and possible association with vaccine allergy. Patients diagnosed with alpha-gal syndrome (AGS) from 2018 to 2024 were selected in this study. AGS was identified by the occurrence of allergic symptoms up to 8 h of ingestion of red meat, with positive serum IgE to alpha-gal > IgE to red meat, and negative IgE to BSA. Allergy to vaccines containing bovine products were also identified in patients with AGS. Fifty-seven patients were identified. Thirty-one (54.3%) were 12 years or younger. There were more females among adults (63.2%) compared to children (50.0%), though statistically not significant. There was no difference between children and adults in relation to clinical features and time of onset of symptoms. However, 5/6 of adults with severe anaphylaxis (grade 5) were females. Six patients with AGS developed allergy, including anaphylaxis, to the measles, mumps, rubella (MMR, n = 3), rubella (n = 1), varicella (n = 1) and anti-rabies (n = 1) vaccines. AGS is an important cause of food and vaccine allergy in the Indian subcontinent and is commoner in children unlike in other regions. However, the clinical features are similar to adults.
de Silva R, Karunatilake C, Iddagoda J, Dasanayake D
The World Allergy Organization journal •
The incidence of IgE mediated food allergy (FA) is increasing in the west. Cow's milk (CM), hen's egg, wheat, soy, peanut, tree nut, fish, and shellfish are responsible for 90% of food allergy in the west; however, local dietary habits may result in specific allergies. Data on food allergies in South Asia is scarce. The present study aims to evaluate the foods that cause immediate type hypersensitivity in Sri Lanka, and to compare with Asia and the developed west. Records of patients referred to an Immunology clinic from 2010-January 2022 were reviewed. The diagnosis of food allergy was based on standard guidelines. Confirmation of the specific food implicated was based on the history and the presence of specific IgE or component resolved diagnostics by in vitro methods (Phadia ImmunoCap) or by skin prick testing with commercial extracts (Alk Abello). Prick to prick testing was performed for fruits and vegetables when commercial extracts were unavailable. Three hundred and forty-six patients were confirmed with food allergy. CM allergy (CMA) was the commonest (31.2%) followed by red meat allergy (27.7%) and food dependent exercise induced anaphylaxis (FDEIA) (17.9%). Allergy to alpha-gal crustaceans, eggs, gelatin, wheat, coconut milk, and mollusks were seen in 2-10% of patients.The onset of CMA was mainly in childhood. However, in 23/108 patients, onset was after 5 years, including 8 patients in adulthood, and in 14 of the 23, it was preceded by red meat allergy. Onset of primary red meat allergy was predominantly in children, but in 33/96 (34.3%) of patients, it was in adults. Most patients with alpha-gal allergy (21/29, 72.4%) had initial symptoms in childhood and adolescence.Anaphylaxis was diagnosed in 213 patients. FDEIA is the commonest cause (24.7%) followed by red meat allergy (23%), CMA (21.5%) and alpha-gal allergy (10.3%). Allergy to peanuts and fruits were rare.Patients with red meat allergy and/or CMA developed allergy, including anaphylaxis, to vaccines containing bovine/porcine products. CM was the most common food allergy in children, but egg allergy was uncommon. Primary red meat allergy was the second most common, and was associated with allergy to vaccines containing bovine products, such as the measles, mumps and rubella (MMR) vaccine. Allergy to peanuts and fruits were rare. Primary red meat allergy may be responsible for late onset CMA.
de Silva NR, Dasanayake WMDK, Karunatilake C, Wickramasingha GD, De Silva BD, et al.
Allergy, asthma, and clinical immunology : official journal of the Canadian Society of Allergy and Clinical Immunology •
The aetiology of anaphylaxis differs according to types of foods consumed, fauna and foliage and cultural practices. Although the aetiology of anaphylaxis in Western countries are well known, the causes in South Asian countries have not been reported. We sought to determine the causes of anaphylaxis in patients referred to an immunology clinic in Colombo, Sri Lanka. 238 episodes of anaphylaxis were reviewed in 188 patients who were referred and skin prick tests and in vitro tests (ImmunoCap) were carried out to assess the presence of allergen specific IgE. Clinical features and severity of anaphylaxis was also recorded along with treatment received. Anaphylaxis to food either following direct exposure 90/238 (37.5%) or after exercise in the form of food dependent exercise induced anaphylaxis 29/238 (12.2%) was the predominant cause of anaphylaxis. Allergy to cow's milk and red meat, after immediate exposure, accounted for 66/238 (27.7%) of instances of all episodes of anaphylaxis and 66/90 (73.33%) of anaphylaxis due to food. Vaccines accounted for 28/238 (11.8%) of instances of anaphylaxis, especially among children. Of those who developed anaphylaxis to the MMR (n = 14), 71.4% of them had specific IgE to cow's milk and 35.7% of them had specific IgE to beef. Of those who developed anaphylaxis to insect stings, 27/42 of these episodes occurred following stings of ants (family Formicidae). The predominant cause of anaphylaxis changed with the age, with food allergy being the most frequent trigger of anaphylaxis in childhood, while drug allergy and idiopathic anaphylaxis being more frequent after 30 years of age. In this cohort, anaphylaxis to red meat appears to be the predominant cause of food induced anaphylaxis and presence of beef specific IgE and cow's milk, appears to be a predisposing factor for vaccine induced anaphylaxis.