Figure 1. Slightly raised tan to reddish-brown urticaria pigmentosa lesions of the hand.

Figure 2. Urticaria pigmentosa seen in systemic mastocytosis. These lesions have a reddish-brown to slightly purple hue.

Figure 3. Diffuse macular reddish-brown lesions of urticaria pigmentosa seen in systemic mastocytosis.

Figure 4. Scattered macular lesions of urticaria pigmentosa. Slight rubbing of the lesions causes pruritus and edema. This is known as Darier's sign.