Urticaria pigmentosa (UP) is a rare skin condition caused by the accumulation of mast cells under the skin. UP is associated with a genetic mutation in the c-kit gene, which is responsible for the production of the mast cell.
UP is typically diagnosed by physical examination and skin biopsy. The skin biopsy will reveal the presence of mast cells.
UP can be confused with other skin conditions such as dermatomyositis and erythema nodosum. It is important to differentiate UP from these conditions because they may require different treatment regimens.
Treatment for UP is aimed at reducing the number of mast cells. This can be achieved through the use of antihistamines, steroids and phototherapy. In some cases, surgery may be necessary to remove the affected area.
The prognosis for UP is generally good. Most patients will experience a full resolution of symptoms with proper treatment. However, recurrences are possible and the condition can last for several years.