What does atopy mean?
Atopy is a medical noun describing an inherited tendency to develop allergic hypersensitivity reactions to ordinarily harmless environmental substances such as pollen, dust mites, animal dander, and certain foods. People with atopy are prone to conditions including atopic dermatitis (eczema), allergic asthma, and allergic rhinitis (hay fever), all of which involve heightened production of IgE antibodies. The term is standard in clinical practice, where phrases like 'atopy', 'atopic disease', and 'the atopic march' — the typical progression from eczema in infancy to asthma and hay fever later in childhood — appear frequently. Derived from the Greek for 'out of place' or 'strange', it was coined in the early twentieth century when these conditions were recognised as distinct from ordinary immune responses. Atopy is a useful word for anyone reading medical literature or discussing family health history precisely, though general conversation usually prefers simpler terms like 'allergies'.
nounA genetic predisposition to developing allergic hypersensitivity reactions, such as asthma, hay fever, and eczema, in response to common environmental allergens.
- A hereditary predisposition to type I hypersensitivity (IgE-mediated) allergic conditions such as asthma, allergic rhinitis, and atopic dermatitis.
"A family history of atopy made it unsurprising that both children developed asthma."
"Patients with atopy often show elevated levels of IgE antibodies against everyday substances like pollen and dust mites."
"The paediatrician asked whether there was any atopy in the family before diagnosing the infant's persistent rash."
Rarely pluralised; the uncountable form is almost always used, since atopy refers to a general predisposition rather than countable instances.
"Different atopies can present within the same family, one child with eczema and another with asthma."
The word 'atopy' literally means 'out of place' in Greek — coined because doctors found these strange, placeless allergies that didn't fit any known pattern of disease.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of atopy
Atopy derives from the Greek 'atopia', meaning strangeness or being out of place, formed from 'a-' ('not') plus 'topos' ('place'). The term was introduced into medical usage in the early twentieth century by physicians who observed that certain patients developed peculiar allergic reactions that seemed to have no obvious cause or fixed location. It shares its root with other English words built on 'topos', including 'topic', 'topography', and 'utopia'.
Word family
Usage notes
Atopy is a technical term used chiefly in medical and scientific contexts; lay speakers more often say 'a family history of allergies'. The adjective 'atopic' is very common in clinical phrases such as 'atopic dermatitis'. It carries no informal register and is neutral rather than pejorative.
Don't confuse with
Atopy is an inherited tendency to develop allergies, whereas anaphylaxis is an acute, potentially life-threatening allergic reaction itself.