Urticarial Pigmentosa is a skin disease that occurs when the body produces too many mast cells –blood cells that support the immune system. The condition associated with the overabundance inflammatory cells in the skin is known as cutaneous mastocytosis. Urticarial pigmentosa is the most common variety of cutaneous mastocytosis.
Although urticarial pigmentosa is seen most often in children as many as one-third of cases occur in adults. Brown to reddish skin spots or patches develop on the trunk of the body and quickly spread in a symmetrical pattern. The lesions rarely occur on the face, scalp, palms and soles but can develop on the mucus membranes.
The symptoms of urticarial pigmentosa in adults are often more severe than in children and may include: flushing of the face, diarrhea, headache, accelerated heart rate or hypotension. Some cases progress to systemic mastocytosis.
Dermatologists typically recognize the condition by the skin symptoms alone. Skin biopsy may be done to confirm the diagnosis. Simply rubbing the lesions may provide another clue that it is urticarial pigmentosa, since this elicits a burning or itching sensation and causes the lesions to swell and become reddened. This skin response is known as Darier’s sign.
Blood tests may also be recommended to identify the presence of tryptase, an enzyme associated with mastocytosis, along with urine tests to check for excreted histamine.
Treatment of urticarial pigmentosa is aimed at symptom relief. Dermatologists usually recommend antihistamines to relieve itching and redness. Other treatment therapies include topical or injected steroids and PUVA (photochemotherapy).
Aspirin therapy may be beneficial but can worsen symptoms in some patients. Exercise, heat and bee stings can trigger symptoms flare-ups. Talk with your dermatologist about whether or not you should carry injectable emergency epinephrine.