Whisk mayonnaise, chipotle powder, and lime juice together in a mixing bowl. Cover with plastic wrap and refrigerate until needed for serving.
Whisk egg white, ice water, and salt together in a large mixing bowl until mixture is light and foamy, 1 or 2 minutes. Add cornstarch and flour; whisk together until thoroughly mixed. Batter should resemble a thin pancake batter. Stir in corn.
Heat 1/2 inch vegetable oil to 350 degrees F (175 degrees C) in a seasoned cast iron skillet. Spoon about 2 large spoonfuls of batter into oil for each fritter. Do not crowd, cook in batches, if necessary. Fry until browned and crispy, about 2 minutes per side. Turn fritters carefully to avoid spattering the oil. Drain on paper-towel-lined plate.
Serve topped with fresh Dungeness crab and drizzle with the chipotle dressing. Serve with a wedge of lime.