D3.288 - Asthma and Anaphylaxis Induced by Milk with NSAID as a Cofactor in Adult Patient Sensitized to Dairy Proteins Due to Environmental Exposure in a Dairy Farm

BACKGROUND.  Cow’s milk allergy (CMA) in adults is rare, especially when appearing after the age of 40. Occupational or environmental exposure to airborne milk proteins has been identified as a potential sensitization route. Individuals exposed to dairy bioaerosols may develop respiratory symptoms and, in some cases, systemic allergic reactions upon subsequent ingestion of milk-derived products. We present a case of an adult patient who experienced anaphylaxis upon milk ingestion with NSAID (naproxen) as a cofactor.

CASE REPORT. A 43-year-old male, non-dairy worker, living adjacent to a dairy farm presented with episodes of severe anaphylaxis and worsenig asthma after ingesting milk-containing products, with the most severe reactions occurring when combined with naproxen use. Personal History: optician, with Asthma and allergic rhino-conjunctivitis to pollens and fungi. Family History: Daughter with severe asthma and anaphylaxis. Reported anaphylaxis episodes: 2019: Generalized urticaria, hoarseness, and respiratory distress after ingesting naproxen and yogurt, coinciding with direct exposure to dairy farm air. He was treated with IM epinephrine, corticosteroids, and bronchodilators. 2021: Severe anaphylaxis after consuming machine-made coffee with >76% milk. He required also emergency treatment. ALLERGY STUDY. Skin prick tests (SPT): positive to milk (8×8 mm), β-lactoglobulin (6×4 mm), casein (3×3 mm). Serum specific IgE (sIgE) trends over time: Cow´s Milk: 4.1 kU/L (2018) → 0.44 kU/L (2021). β-Lactoglobulin: 7.1 kU/L (2018) → 0.74 kU/L (2021). Alternaria: 2.5 kU/L (2018) → 0.7 kU/L (2024). Total IgE: 218 IU/mL (2019) → 122 IU/mL (2021). Pulmonary function tests: 2019 FEV1 4020 ml (86%) → 2020 FEV1 4340 ml (110%) → 2024 FEV1 4540 ml (116%). Drug challenge: NSAIDs acted as a cofactor, facilitating allergen absorption and amplifying reactions. Meloxicam was well tolerated. Oral immunotherapy (OIT) Patient completed OIT with milk up to 40 mL/day, followed by avoidance of NSAIDs and dairy. 

DISCUSSION. Several milk allergens were identified as potential airborne triggers: casein (Bos d 8) Heat-stable, resistant to digestion; β-Lactoglobulin (Bos d 5) major inhalation allergen in dairy settings; Bovine Serum Albumin (BSA: Bos d 6) in epithelium, saliva, and airborne farm particles, contributes to inhalation sensitization; Lactoferrin (Bos d LF) in milk, feces, and bioaerosols, linked to dairy farm sensitization; Lactoperoxidase (Bos d LP) in saliva and respiratory secretions, airborne allergen potential. 

CONCLUSION. This case highlights the importance of environmental exposure to airborne dairy allergens as a sensitization route in adults, particularly in non-occupational settings. Bioaerosol-mediated allergic sensitization should be considered in adults with unexplained CMA or respiratory symptoms near dairy farms. Moreover, NSAIDs should be carefully assessed as cofactors in food-induced anaphylaxis. OIT with milk helped to control asthma and anaphylaxis.