A keloid is an overgrowth of scar tissue that forms when there is excess collagen during the healing process of a skin injury. Common injuries where keloids form are from burns, piercings, acne and surgical incisions. They are often raised, hairless and hard. They can be itchy or have a burning sensation but are usually painless.

A study found that the overall migraine risk was 2.29 times greater in the keloids cohort compared with a non-keloid cohort after adjustment for age, gender and relevant comorbidities.1

Risk factors for migraine in the keloid group were stroke, fibromyalgia, insomnia, anxiety, asthma and female gender, which are all comorbid with migraine.1