Urticaria pigmentosa

Alternative Names

Mastocytosis; Mastocytoma

Definition of Urticaria pigmentosa

Urticaria pigmentosa is a skin disease that produces and intense itching. If you rub the lesions, hives may develop.

Causes, incidence, and risk factors

Urticaria pigmentosa is one of several forms of mastocytosis, which occurs where there are too many inflammatory cells (mast cells) in the skin.


The main symptom is brownish lesions on skin. Rubbing the skin sore causes a hive-like bump. Younger children may develop a fluid-filled blister if it is scratched.


Antihistamines may relieve symptoms such as itching and flushing. Discuss the choice of antihistamine with your child’s health care provider. Other medications may be recommended for symptoms of more severe and unusual forms of urticaria pigmentosa.

Expectations (prognosis)

Urticaria pigmentosa goes away by puberty in about half of the affected children. Symptoms usually get better in others as they grow into adulthood.


Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 10/10/2010

Dermatographism - close-up
Dermatographism on the arm
Urticaria pigmentosa in the armpit
Mastocytosis, diffuse cutaneous
Urticaria pigmentosa on the chest
Urticaria pigmentosa - close-up
Dermatographism on the back

ADAM Medical Encyclopedia

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