Itch is a universally known sensation and is one that is shared by most animals. While we’re all familiar with the feeling, from a scientific standpoint, we know surprisingly little about it. It’s not difficult to see how itching can be beneficial—it induces a reflex scratch that can remove insects, dirt, and other irritants from the skin, which, if left untouched, can damage the skin or cause infection. The problem is when itch induces scratching to the degree that it becomes harmful rather than helpful.
Itch and Scratch
Those with chronic skin conditions like eczema or psoriasis that cause itch are aware of how frustrating itch can be. Itch also induces scratching, which will damage the skin further, quickly amplifying the damage and resulting in further itch. This well-known feedback loop is called the itch-scratch cycle and is one of the challenges of managing chronic skin problems. The itch-scratch cycle is a significant factor in flare-ups, where a skin problem worsens in a short period of time.
Controlling the Itch
While most children are taught not to scratch, this can be a challenge. In fact, in most cases, this is an impossible feat, as scratching is mostly a reflex. If the itch is strong enough, the reflex cannot be suppressed. Scratching during sleep is another common problem and one that is difficult if not impossible to control. Intense or sustained itch is near impossible to control through force of will alone. Stopping the cycle starts with suppressing the itch as fast as possible through an aggressive intervention.
Excessive scratching damages the skin and is harmful behavior. It can damage the skin, cause further inflammation, and aggravate existing conditions.