Research examining serotonin's role in the skin found that abnormal levels of serotonin cause mice to itch. Researchers also found that when serotonin is released in response to pain, certain receptors are activated that cause itchiness.
Scratching the itch causes the release of serotonin as a pain reliever, which activates the receptors again and causes more itching.
Selective serotonin reuptake inhibitors (SSRIs), such as sertraline and fluoxetine, may help to reduce skin itching.
Medications that are used to treat fibromyalgia, including pain relievers, antidepressants, and anti-seizure drugs, can sometimes have side effects of itching in certain people. These medications include:
- Acetaminophen - has a rare side effect of skin, rash, hives, or itching
- Ibuprofen - one of the more common side effects is itching skin
- Naproxen sodium - itching is a common side effect
- Tramadol - itching skin is a common side effect
- Duloxetine and milnacipran - burning, crawling, itching, numbness, prickling, "pins and needles," or tingling feelings are less common side effects
- Pregabalin - itching is a rare side effect
If itching is experienced with fibromyalgia medications, people should check with a doctor to ensure that the symptoms are not an allergic reaction. In some cases of itching, the dosage or medication may need to be altered.