Formication

It feels as though tiny insects are moving across the skin of your arms, legs, back, or scalp, or sometimes as though something is wriggling just beneath your skin. Even when you brush your hand over the area and find nothing there, the sensation is distinct, which can be quite unsettling the first time it happens.

In medicine, an abnormal sensation that occurs without any stimulus is called paresthesia, and an unpleasant sensation of this kind is called dysesthesia. A crawling sensation is one way of describing this dysesthesia. The same type of dysesthesia may be experienced as shooting pain or a burning sensation by some people, while others describe it as “bugs crawling.” These are simply different ways of putting sensory signals into words; all are related to signals sent by nerves.

It is difficult to identify a specific cause from this sensation alone. It is known to occur in a range of situations, mainly including the following.

• When skin is dry or itchy — When your skin dries out in winter or after a shower, it becomes sensitive to even minor stimuli.
• During hormonal changes — Some people experience this sensation around menopause.
• When peripheral nerves become more sensitive — It sometimes occurs alongside other forms of dysesthesia in conditions that affect peripheral nerves, such as diabetes, or conditions involving thin nerve fibers, such as small fiber neuropathy.
• Around a migraine — Some people notice changes in skin sensation before a headache begins.
• When stopping medication, drugs, or alcohol — It has been reported when certain medications, drugs, or alcohol are abruptly reduced.
• When fatigue and tension build up — Some people become more sensitive to sensations when they are short on sleep or physically tense.

If dry skin or fatigue is the cause, it often settles within a few days with moisturizing and rest. If it is related to hormonal changes, symptoms may come and go over several weeks to several months. Many people notice it more clearly when lying down to sleep at night or when their surroundings are quiet. Another characteristic is that it can become less noticeable when you focus on something else.

• Keep your skin moisturized. Applying lotion or cream within 3 minutes after a shower can reduce sensitivity caused by dry skin.
• Wash with lukewarm water. Hot water can easily make your skin drier.
• Try gentle pressure instead of scratching. Scratching can damage your skin and make it more sensitive. Gently pressing with your palm or placing a cold towel over the area can make it feel more comfortable.
• Cut back on caffeine and alcohol. If it gets worse after evening coffee or late-night drinking, try adjusting the timing.
• Check your sleep and tension levels. Keeping a consistent bedtime and relaxing your body with gentle stretching or breathing before bed can help.
• Write down when and where you feel it. A few notes about the time of day, body area, medications taken, and beverages consumed can make it easier to explain to a doctor or other professional later.

Most cases are not a major cause for concern, but if you notice any of the following signs, review any newly started medications and your health status as well.

• It continues for several weeks or gradually gets worse
• It occurs only in an arm or leg on one side, along with weakness or reduced sensation
• It happens often enough to interfere with sleep
• It began after you started taking a new medication
• A rash develops, or wounds caused by scratching do not heal

In these situations, make a note of when it started and which medications you take, and discuss this with a doctor.