From the Guidelines
The medical term for when pushing on the skin leaves a trace or indentation in urticaria is "dermographism" or "symptomatic dermographism". This phenomenon occurs when stroking or applying pressure to the skin causes raised, red welts to appear along the lines where pressure was applied, as described in the guidelines for evaluation and management of urticaria in adults and children 1. The skin essentially "writes" in response to touch, hence the name dermographism (meaning "skin writing"). In typical dermographism, the welts appear within minutes of pressure application and may last for 30 minutes to a few hours before fading. This reaction happens because pressure triggers mast cells in the skin to release histamine and other inflammatory chemicals, causing local swelling, redness, and sometimes itching. Some key points to consider about dermographism include:
- It is considered a form of physical urticaria, as outlined in the clinical classification of urticarias 1
- The weals of physical urticaria are gone within an hour except those in delayed pressure urticaria, which take 2–6 h to develop and up to 48 h to fade 1
- Dermographism affects a portion of the population and can be managed with treatment and lifestyle adjustments
- Treatment typically includes non-sedating antihistamines, which can be taken regularly to prevent reactions, and avoiding tight clothing and reducing skin friction may also help minimize symptoms.
From the Research
Definition and Causes
- The medical term for the condition where pushing the skin leaves a trace on the skin in urticaria is known as dermographism 2, 3.
- Dermographism is a common subtype of chronic urticaria, which manifests as a linear wheal after scratching or friction, with or without angioedema 3.
- The pathophysiology of dermographism is not clear, but it is believed that mechanical stress leads to the activation of mast cells, which provoke the release of histamine and pro-inflammatory mediators, ultimately forming a wheal along the stressed area 3.
Diagnosis and Treatment
- The gold standard for diagnosis is a medical history and provocation test or dermatographic test 3.
- The Urticaria Control Test (UCT), Chronic Urticaria Quality of Life questionnaire (CU-Q2oL), and Dermatology Life Quality Index (DLQI) are also effective tools for evaluating disease control in dermographism patients 3.
- Treatment options include nonsedating H1 antihistamines as the first-line medication, with the possibility of increasing the dosage up to 4 times for those who do not respond to standard doses 3, 4.
- Omalizumab can be considered for recalcitrant patients, and other drugs with potential therapeutic effects are still being explored 3, 4.