Familial urticaria pigmentosa.

We describe urticaria pigmentosa in three generations of a kindred. Unique to this family is the marked diversity of their skin disease. Classic lesions of urticaria pigmentosa, telangiectasia macularis eruptiva perstans, and clinically normal skin with positive dermal infiltrates of excess mast cells were found in individual family members. Urticaria pigmentosa is rarely reported as an inherited disease. To our knowledge, this is the largest American kindred of familial mast cell disease and is the second report documenting disease in three generations.