Urticaria pigmentosa is the name given to a type of mastocytosis, in which there are brown patches on the skin due to abnormal collections of mast cells. When the mast cell is disturbed, chemicals such as histamine are released into the surrounding skin, making the blood vessels leaky, and resulting in localized itching, swelling and redness.
Urticaria pigmentosa most often affects infants, with the first patches appearing at a few months of age. They may look like insect bites at first, but gradually increase in number for several months or years. They can appear on any part of the body. Luckily, over the years the urticaria pigmentosa patches usually fade away and disappear by the time the child is a teenager.
When urticaria pigmentosa develops for the first time in an adult, however, it tends to persist long term, and is more likely to be associated with internal symptoms.
Certain medications which can cause mast cell degranulation and are usually avoided include:
Alcohol should also be avoided.
- Aspirin (salicylates)
- Codeine and morphine (narcotics)
Some patients seem to do best when they avoid all or most of the salicylate-containing foods as well.
Links: - Studies on PST, Salicylates, and Sulfation
- More information about PST and behavior