Darier's sign
Pronunciation: dah-ree-AYZ
Urticaria and swelling that occurs when mastocytosis lesions are rubbed or stroked.
Full Definition
Darier's sign is a characteristic clinical finding in mastocytosis lesions, manifesting as the development of urticaria, swelling, erythema, and sometimes blistering when the lesion is gently rubbed or stroked. This reaction occurs due to the release of histamine and other inflammatory mediators from the abundant mast cells within the lesion. A positive Darier's sign is pathognomonic for mastocytosis and helps differentiate these lesions from other pigmented skin conditions. The test should be performed gently to avoid excessive trauma, particularly in infants.
Usage
Usage note: Capitalize as it's an eponym; always test gently, especially in young children who may develop blistering.
In Context
- "Darier's sign was positive, confirming the clinical suspicion of mastocytosis." — Physical examination documentation
- "Parents were advised to avoid vigorous rubbing of the lesion due to the positive Darier's sign." — Patient education note