Allergy Reference Library

Peanut allergy is one of the most common and potentially severe food allergies. Even trace amounts can trigger anaphylaxis in sensitised individuals, making vigilant label reading and emergency preparedness essential.

Tree nut allergy covers a broad group of nuts — almonds, cashews, walnuts, pistachios, hazelnuts and others. Reactions range from mild oral tingling to severe anaphylaxis, and allergies to multiple tree nuts are common.

Shellfish allergy is one of the most common adult-onset food allergies and among the most persistent — it rarely resolves with age. Crustaceans (shrimp, crab, lobster) and molluscs (oyster, squid, clam) can each trigger reactions.

Cow's milk allergy (CMA) is one of the most common childhood food allergies, affecting 2–3% of infants. It involves an immune response to milk proteins — casein and whey — and is distinct from lactose intolerance, which is not immune-mediated.

Egg allergy is one of the most common childhood food allergies. Reactions typically occur to egg white proteins, though some individuals also react to yolk. Most children outgrow it by adolescence.

Wheat allergy is an immune reaction to proteins in wheat — distinct from coeliac disease (an autoimmune condition) and non-coeliac gluten sensitivity. It can cause immediate IgE-mediated reactions or delayed symptoms.

Soy allergy is common in infants and young children, particularly those with cow's milk allergy. Most reactions are mild, but severe reactions can occur. Soy is one of the top food allergens and is found in an enormous range of processed foods.

Sesame allergy is increasingly recognised as a major food allergen. It often persists into adulthood and can cause severe reactions. Sesame is now a mandatory declared allergen in many countries including the UAE and the United States.

Penicillin is the most commonly reported drug allergy, but studies show fewer than 10% of those labelled 'penicillin allergic' have a true allergy. Accurate diagnosis matters because mislabelled patients receive broader-spectrum, costlier, and less effective antibiotics.

Adverse reactions to non-steroidal anti-inflammatory drugs (NSAIDs) including aspirin, ibuprofen, and naproxen affect up to 2% of the population. They range from mild hives to severe anaphylaxis, and may be immunological (true allergy) or non-immunological (intolerance).

House dust mite (HDM) allergy is the most common cause of perennial (year-round) allergic rhinitis and allergic asthma worldwide. The allergens are proteins in mite faeces and body fragments — not the mites themselves.

Pollen allergy — commonly called hay fever or allergic rhinitis — is a seasonal immune response to airborne pollen from trees, grasses, or weeds. It affects up to 30% of adults and is the leading allergic disease globally.

Pet dander allergies — most commonly to cats and dogs — are triggered by proteins in animal skin cells (dander), saliva, and urine, not by pet fur itself. Cat allergy is about twice as common as dog allergy and produces particularly potent allergens.

Mould spore allergy causes both seasonal and perennial allergic rhinitis and asthma. Key moulds include Alternaria, Cladosporium, Aspergillus, and Penicillium — each with distinct seasonal and indoor exposure patterns.

Nickel is the most common cause of allergic contact dermatitis worldwide. The reaction occurs when nickel-containing metal contacts skin over time, causing an itchy, red, blistering rash at the point of contact.

Latex allergy is an immune reaction to natural rubber latex proteins. It is particularly significant for healthcare workers and patients with frequent surgical procedures. Reactions range from contact dermatitis to anaphylaxis.

Most people experience local pain and swelling after a bee or wasp sting. But 1–3% have an allergy that triggers systemic reactions or anaphylaxis — a life-threatening emergency. Venom immunotherapy provides up to 95% protection against future severe reactions.