Definition:
Urticaria pigementosa is a rare disease and is the most common form of cutaneous mastocytosis.
Diagnosis:
A skin biopsy and examining the level of histamine on the urine can diagnose the disease.
Treatment:
The disease has no permanent cure but treatments are possible. Anti-allergy medications are generally useful since they reduce the mast cell’s ability to react to histamine. There is a clinical study suggesting that nifidepine, an anti-hypertensive medicine, may reduce mast cell degranulation in patients with urticaria pigmentosa. The said medicine however had never been approved by the FDA to treat the disease.
Symptoms and Signs:
The disease is characterized by excessive amounts of mast cells in the skin. Often seen on the skin are red or brown spots typically around the chest and forehead area. When rubbed or exposed to heat, the mast cells produce too much histamine that could trigger an allergic reaction. It could also lead to hives localized to the area of irritation, which is sometimes referred to as Darier’s sign. The symptoms can range from mil to life-threatening.
Causes:
Most Urticaria pigmentosa cases are caused by a point at amino acid 816 of the proto-oncogene c-kit, a transmembrane protein which, when bound to Mast Cell Growth Factor (MCGF), signals the cell to divide.
