Perineural Incobotulinumtoxin-A for Complex Regional Pain Syndrome - An Open-label Feasibility Study

Inclusion Criteria: * Are over the age of 18 * Have a diagnosis of CRPS type 1 or 2 in either one upper or one lower extremity which fulfils the Budapest research criteria * Have had the condition for at least 6 months * Rate CRPS as their primary pain condition * Have been on a stable analgesic regimen, including any rescue medications, for at least 1 month prior to the study and intend to maintain this regimen throughout the study * For pre-menopausal females: are using a safe and approved contraceptive * Speak, read, and understand Danish Exclusion Criteria: * Are allergic to botulinum toxin A * Have been treated with botulinum toxin A for any indication within 3 months prior to study start * Are diagnosed with myasthenia, Lambert-Eaton syndrome, amyotrophic lateral sclerosis, or any other condition which makes differentiation of CRPS-specific pain difficult * Have an ongoing infection in the affected limb * Do not intend to start physical therapy, psychotherapy, or any other non-pharmaceutical intervention aimed at reducing pain * Have used a topical analgesic treatment such as lidocaine patches within 1 week prior to study start or have been treated with capsaicin patches in the affected area within 3 months prior to study start * Have psychiatric comorbidities which are considered by the investigators to impact their ability to participate * Consume alcohol in excess of what is recommended by the Danish Health Ministry * Are active abusers of illicit narcotics * Are pregnant, lactating, or plan on becoming pregnant during the study period * Have any other condition or circumstance that, in the investigators' opinion, will hinder safe and timely participation and completion of the study