why does sunburn itch

Sunburn itches mainly due to a process called neurogenic inflammation, where UV damage from the sun activates nerve endings in the skin and triggers an inflammatory response. This causes the release of histamines, which lead to redness, pain, and the itchy sensation. Additionally, as the skin starts to heal, new cells push upwards while the damaged outer layer dries and peels, overstimulating sensory nerves and intensifying the itch. The itch can be worse in sensitive or previously damaged skin, such as skin with eczema or scar tissue, because these areas lose moisture more quickly and may have abnormal nerve growth making them more reactive to the sunburn. This dryness and nerve overactivation contribute to a stronger itching sensation. Severe itching after sunburn is sometimes called "hell's itch," and it reflects a deeper nerve irritation that can be quite intense. In summary, sunburn itch is caused by skin inflammation, histamine release, nerve activation, and skin dryness as it heals from UV damage.