What is dermatographism?

Dermatographism, also known as skin writing, is a condition characterized by localized whealing that occurs in response to physical stimuli, such as pressure or scratching on the skin. When the skin is scratched or pressed, it releases histamine and other inflammatory mediators, leading to raised, red welts that can develop quickly and may be itchy or uncomfortable.

This condition is often benign and can be triggered by various factors like heat, sweating, or even tight clothing. Patients typically find that these wheals last for a short period before resolving, making the identification of dermatographism relatively straightforward in clinical practice. Understanding this mechanism is key to distinguishing it from other dermatological conditions which may not involve this immediate whealing response to direct pressure on the skin.