Atopic

Atopic is an adjective used in medical contexts to describe a tendency to develop allergic diseases that run in families. People described as atopic are more prone to produce IgE antibodies in response to common environmental substances and may present with conditions such as atopic dermatitis (eczema), allergic rhinitis, asthma, and certain food allergies.

The term derives from Greek atopos, meaning "out of place." It entered medical usage to denote a predisposition to allergic responses rather than a specific disease, and it is used to categorize a group of related conditions that share a genetic background.

Pathophysiology of atopy involves a complex interaction between genetics and environment. A hereditary predisposition leads to a propensity for IgE-mediated responses to allergens. Skin barrier dysfunction, particularly with mutations in genes like filaggrin, can increase sensitivity to environmental triggers. Immune responses in atopy are frequently skewed toward a Th2-type profile, promoting allergic inflammation.

Clinically, atopy refers to individuals who exhibit this predisposition and to the group of diseases commonly associated with it, including atopic dermatitis, allergic rhinitis, asthma, and food allergies. The concept of the atopic march describes how some individuals may develop dermatitis in infancy followed by allergic rhinitis and asthma later in childhood.

Not all people with one allergic condition are atopic in a broader sense, and some individuals may have sensitizations without clinical symptoms. Management typically focuses on symptom control and trigger avoidance, often using moisturizers for skin, anti-inflammatory therapies, and, in some cases, allergen-specific immunotherapy. There is no cure for atopy, but many individuals achieve good control with appropriate care.