Darier's sign is a change observed after stroking lesions on the
skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other animal coverings, such as the arthropod exoskeleton, have different ...
of a person with
systemic mastocytosis
Mastocytosis, a type of mast cell disease, is a rare disorder affecting both children and adults caused by the accumulation of functionally defective mast cells (also called ''mastocytes'') and CD34+ mast cell precursors.
People affected by masto ...
or
urticaria pigmentosa.
In general, the skin becomes
swollen,
itch
An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both ...
y and
red
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–750 nanometres. It is a primary color in the RGB color model and a seconda ...
.
This is a result of compression of
mast cell
A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a p ...
s, which are hyperactive in these
disease
A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...
s. These mast cells release
inflammatory granules which contain
histamine
Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Discovered in 19 ...
. It is the histamine which is responsible for the response seen after rubbing the lesional skin.
History
Darier's sign is named after the French dermatologist
Ferdinand-Jean Darier (1856–1938) who first described it.
See also
*
Dermatographic urticaria
Dermatographic urticaria is a skin disorder and one of the most common types of urticaria, affecting 2–5% of the population.
Signs and symptoms
The condition manifests as an allergic-like reaction, causing a warm red Wheal response, wheal to a ...
References
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Dermatologic signs