Background: Illicit drugs, tobacco, and alcohol contain allergens that can trigger, inadvertently affecting children living with consumer relatives.

Objective: This real-life study is aimed to evaluate the presence of sensitization to illicit drugs (cannabis, opium derivatives, and cocaine), tobacco, and allergens derived from alcoholic beverages in children.

Methods: Children (0-14 years) with severe allergic symptoms and domestic exposure to drugs, tobacco, or alcohol were included. Prick, specific IgE, molecular analysis, and Dot Blot assays were performed. We tested 46 aeroallergens and food, pure cocaine, coca leaf extract, opium, Papaver somniferum seeds, cannabis, tomato, tobacco, latex, malt, hops, and lipid transfer proteins (LTPs) from grapes.

Results: Of the 150 selected patients, 134 completed the study. Among them, 10 tested positive for cocaine, 21 for cannabis, 6 for opioids, 18 for tobacco, 9 for latex, 17 for malt, 13 for hops, and 12 for grape LTPs. A significant association was found between drug, tobacco, and alcohol exposure and the development of severe allergic symptoms (p < 0.001). Specific relationships were observed: cocaine (p < 0.009) and tobacco (p < 0.05) were associated with severe asthma. Malt and cannabis sensitization (p < 0.001) were linked to anaphylaxis, with additional associations found for hops (p < 0.003) and grape LTP (p < 0.006). Molecular assays revealed binding of the IgE from these paediatric patients to the tested samples.

Conclusions: Atopic children may be considered at risk of developing hypersensitivity to allergens from illicit drugs, tobacco, and alcohol. This possibility should not be underestimated.