Urticaria Pigmentosa

It is an uncommon rash which usually affects the arms, necks, legs and trunks of children and young adults. The rashes are made up of reddish brown spots that turn into hives when they are rubbed or scratched. At times the spots blister. This disease is commonly found in children but it can also occur in adults as well.

This disease is mostly found in infants and the first patches appear when the child is few months old. At first they might be confused for insect bites but slowly they develop for several months or years. This condition can appear on any part of the body including the face, trunk, scalp and limbs. In the case of young children the patches get blistered when rubbed.   If many patches get activated at the same time, the infants might become irritable but it is rarely that severe symptoms arise.

Within the next few years the condition becomes less irritable and eventually the patches fade off. When a person enters his teenage most of the patches fade away. In case of the adults this condition persists for a longer time and is also associated with internal symptoms.

No specific tests are required as the appearance of this condition is generally characteristic. At times a skin biopsy is necessary for confirming the diagnosis. One must avoid exercise or heat as it can aggravate the symptoms.

Cause

The spots formed have a large number of mast cells and these are immune cells which live in the skin. The mast cells lead to formation of histamine which leads to itching, hives and flushing. It is still unknown as to why people with urticaria pigmentosa have an abnormal collection of mast cells in the skin.

Symptoms

This disease is characterized by huge amount of mast cells in the skin. One can see brown or red spots on the skin, mainly around the forehead and chest. Irritation of the mast cells produces too much histamine which triggers an allergic reaction that can lead to hives localized to the area of irritation. It is followed by severe itching and scratching the affected area only severe the symptoms. The symptoms could be mild to life threatening.

Treatment

Since it is not a serious disease therefore it does not require any treatments in most of the cases. There are certain treatments which could be helpful in this condition such as oral antihistamines, low doses of aspirin, photochemotherapy, topical steroids and interferon.