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Urticaria pigmentosa
Mastocytosis; Mastocytoma
Urticaria pigmentosa is a skin disease that produces patches of darker skin and very bad itching . Hives can develop when these skin areas are rubbed.
Itching
Itching is a tingling or irritation of the skin that makes you want to scratch the area. Itching may occur all over the body or only in one location...
Causes
Urticaria pigmentosa occurs when there are too many inflammatory cells (mast cells) in the skin. Mast cells are immune system cells that help the body fight infections. Mast cells make and release histamine, which causes nearby tissues to become swollen and inflamed.
Things that can trigger histamine release and skin symptoms include:
- Rubbing the skin
- Infections
- Exercise
- Drinking hot liquids, eating spicy food
- Sunlight, exposure to cold
- Drugs, such as aspirin or other NSAIDs, codeine, morphine, x-ray dye, some anesthesia drugs, alcohol
Urticaria pigmentosa is most common in children. It can also occur in adults.
Symptoms
The main symptom is brownish patches on the skin. These patches contain histamine. When histamine is triggered, the patches develop into hive-like bumps. Younger children may develop a blister that is filled with fluid if the bump is scratched.
Blister
A vesicle is a small fluid-filled blister on the skin.
The face may also get red quickly.
In severe cases, these symptoms may occur:
- Diarrhea
-
Fainting
(uncommon)
Fainting
Fainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...
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- Rapid heartbeat
Exams and Tests
The health care provider will examine the skin. The provider may suspect urticarial pigmentosa when the skin patches are rubbed and raised bumps (hives) develop. This is called the Darier sign.
Tests to check for this condition are:
-
Skin biopsy
to look for a higher number of mast cells
Skin biopsy
A skin lesion biopsy is when a small amount of skin is removed so it can be examined. The skin is tested to look for skin conditions or diseases. A...
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- Blood tests for blood cell counts and blood tryptase levels (tryptase is an enzyme found in mast cells)
Treatment
Antihistamine medicines can help relieve symptoms such as itching and flushing. Talk to your provider about which type of antihistamine to use. Corticosteroids applied on the skin and light therapy can also be used in some cases.
Your provider may prescribe other kinds of medicine to treat symptoms of severe and unusual forms of urticaria pigmentosa.
Outlook (Prognosis)
Urticaria pigmentosa goes away by puberty in about half of affected children. Symptoms usually get better in others as they grow into adulthood.
In adults, urticaria pigmentosa can lead to systemic mastocytosis. This is a serious condition that can affect bones, the brain, nerves, and the digestive system.
Possible Complications
The main problems are discomfort from itching and concern about the appearance of the spots. Other problems such as diarrhea and fainting are rare.
Bee stings may also cause a bad allergic reaction in people with urticaria pigmentosa. Ask your provider if you should carry an epinephrine kit to use if you get a bee sting.
Bee stings
Bee poisoning is caused by a sting from a bee, wasp, or yellow jacket. This article is for information only. DO NOT use it to treat or manage an act...
When to Contact a Medical Professional
Call your provider if you notice symptoms of urticaria pigmentosa.
References
Habif TP. Urticaria, angioedema, and pruritus. In: Habif TP, ed. Clinical Dermatology: A Color Guide to Diagnosis and Therapy . 6th ed. Philadelphia, PA: Elsevier; 2016:chap 6.
Paller AS, Mancini AJ. Cutaneous tumors and tumor syndromes. In: Paller AS, Mancini AJ, eds. Hurwitz Clinical Pediatric Dermatology . 5th ed. Philadelphia, PA: Elsevier; 2016:chap 9.
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Urticaria pigmentosa in the armpit - illustration
Urticaria pigmentosa is characterized by few to many brownish spots which itch and, when scratched, produce welts and reddened skin. The brown spots contain cells with high levels of histamine. Individuals sometimes develop flushing and headache resulting from the massive release of histamine from these spots. This is the typical appearance of one of these spots (often referred to as a mastocytoma).
Urticaria pigmentosa in the armpit
illustration
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Mastocytosis - diffuse cutaneous - illustration
This is a picture of diffuse, cutaneous mastocytosis. Abnormal collections of cells in the skin (mast cells) produce this rash. Unlike bullous mastocytosis, rubbing will not lead to formation of blisters (bullae).
Mastocytosis - diffuse cutaneous
illustration
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Urticaria pigmentosa on the chest - illustration
Urticaria pigmentosa is characterized by several to many brownish spots that itch and, when scratched, produce welts and reddened skin. The brown spots, seen here on the chest, contain mast cells with high levels of histamine. People sometimes develop generalized flushing and headaches from the massive histamine release from these spots.
Urticaria pigmentosa on the chest
illustration
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Urticaria pigmentosa - close-up - illustration
Urticaria pigmentosa is characterized by several to many brownish spots that itch and, when scratched, produce welts and reddened skin. The brown spots contain mast cells with high levels of histamine. People sometimes develop generalized flushing and headaches from the massive histamine release from these spots.
Urticaria pigmentosa - close-up
illustration
-
Urticaria pigmentosa in the armpit - illustration
Urticaria pigmentosa is characterized by few to many brownish spots which itch and, when scratched, produce welts and reddened skin. The brown spots contain cells with high levels of histamine. Individuals sometimes develop flushing and headache resulting from the massive release of histamine from these spots. This is the typical appearance of one of these spots (often referred to as a mastocytoma).
Urticaria pigmentosa in the armpit
illustration
-
Mastocytosis - diffuse cutaneous - illustration
This is a picture of diffuse, cutaneous mastocytosis. Abnormal collections of cells in the skin (mast cells) produce this rash. Unlike bullous mastocytosis, rubbing will not lead to formation of blisters (bullae).
Mastocytosis - diffuse cutaneous
illustration
-
Urticaria pigmentosa on the chest - illustration
Urticaria pigmentosa is characterized by several to many brownish spots that itch and, when scratched, produce welts and reddened skin. The brown spots, seen here on the chest, contain mast cells with high levels of histamine. People sometimes develop generalized flushing and headaches from the massive histamine release from these spots.
Urticaria pigmentosa on the chest
illustration
-
Urticaria pigmentosa - close-up - illustration
Urticaria pigmentosa is characterized by several to many brownish spots that itch and, when scratched, produce welts and reddened skin. The brown spots contain mast cells with high levels of histamine. People sometimes develop generalized flushing and headaches from the massive histamine release from these spots.
Urticaria pigmentosa - close-up
illustration
Review Date: 10/31/2016
Reviewed By: Kevin Berman, MD, PhD, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
