"Is that a rash on my neck?" It's a common question I get when I see patients with Poikiloderma of Civatte, a change to the skin on the sides of the neck (and chest) that occurs from long term sun exposure to the skin. The sun causes the blood vessels in the skin to become more prominent, the top layer of skin to thin and the color producing cells, the melanocytes, to make an uneven amount of pigment leading to a mottled or net-like look. The central part of your neck, the area under the chin, is shaded and spared from the changes on the side of the neck and chest.
While not a dangerous condition, Poikiloderma of Civatte can be cosmetically unappeaiing. Treatments include lasers and Intense Pulsed Light. The best way to prevent this change to the skin is to avoid sun exposure on the lateral neck and chest with either a high cut hooded shirt or a scarf. Sunscreen can also be helpful but has more limited utility given it can be sweat or rubbed off.