Excoriation disorder, more commonly known as dermatillomania, is a mental disorder on the obsessive–compulsive spectrum that is characterized by the repeated urge or impulse to pick at one's own skin, to the extent that either psychological or physical damage is caused. The exact causes of this disorder are unclear but are believed to involve a combination of genetic, psychological, and environmental factors, including stress and underlying mental health conditions such as anxiety or obsessive-compulsive disorder (OCD). Individuals with excoriation disorder may also experience co-occurring conditions like depression or body dysmorphic disorder (BDD). Treatment typically involves cognitive behavioral therapy and may include medications. Without intervention, the disorder can lead to serious medical complications.

Episodes of skin picking are often preceded or accompanied by tension, anxiety, or stress. During these moments, there is commonly a compulsive urge to pick, squeeze, or scratch at a surface or region of the body, often at the location of a perceived skin defect. When picking, one may feel a sense of relief or satisfaction. In some cases, following picking, the affected person may feel depressed.

The region most commonly picked is the face, but other frequent locations include the arms, legs, back, gums, neck, shoulders, scalp, abdomen, chest, and extremities such as the fingernails, cuticles, toenails, etc. Most patients with excoriation disorder report having a primary area of the body that they focus their picking on, but they will often move to other areas of the body to allow their primary picking area to heal. Individuals with excoriation disorder vary in their picking behavior; some do it briefly multiple times a day, while others can do one picking session that can last for hours. The most common way to pick is to use the fingers although a significant minority of people use tools such as tweezers or needles.

Skin picking often occurs as a result of some other triggering cause. Some common triggers are feeling or examining irregularities on the skin, and feeling anxiety or other negative feelings. This anxiety most commonly stems from a type of OCD, which can range in severity and often goes undiagnosed.

The act of skin picking can occur both consciously (focused picking) and unconsciously (automatic picking). Some individuals may be aware of their behavior but are unable to stop, while others may not realize they are picking until after damage has occurred. The level of awareness can fluctuate, and both forms can be present in the same person.

Complications arising from excoriation disorder include infection at the site of picking, tissue damage, and sepsis. Damage from picking can be so severe as to require skin grafting, and severe picking can cause epidermal abscesses. For example, in one reported case, a 58-year-old man with a history of OCD picked an extensive wound on his left foot, exposing underlying muscle tissue. Severe cases of excoriation disorder can cause life-threatening injuries. According to one reported case, a woman picked a hole through the bridge of her nose, which required surgery to fix, and a 48-year-old woman picked through the skin on her neck, exposing the carotid artery. Pain in the neck or back can arise due to prolonged bent-over positions while engaging in the behavior. Besides physical injuries, excoriation disorder can cause severe physical scarring and disfigurement.

Excoriation disorder can cause feelings of intense helplessness, guilt, shame, and embarrassment in individuals, and this greatly increases the risk of self-harm. Studies have shown that excoriation disorder presented suicidal ideation in 12% of individuals with this condition, suicide attempts in 11.5% of individuals with this condition, and psychiatric hospitalizations in 15% of individuals with this condition.

There have been many different theories regarding the causes of excoriation disorder, including biological and environmental factors.