Efficacy of Topical Morphine in the Treatment of Severe Local Pain of Chronic Wounds

Inclusion Criteria: * Male or female, aged over 18 years * Painful chronic wounds (bedsores, wound tumor, arterial ulcers, venous or mixed diabetic ulcer if systolic pressure index \>0.8, necrotic angiodermatitis not graftable), a bottom surface 300 cm² and does not require more than 15 ml of gel by application. When patient has multiple painful chronic wounds, the wound having only the highest pain intensity is considered for evaluation. * Ineffective systemic analgesic with or without opioid analgesic established and maintained at the same dose for 3 days before inclusion. If treatment includes morphine, the daily dose should not exceed 60 mg of morphine equivalent and this treatment must be a treatment exclusive background. * Patient requiring an analgesic equilibration for intense and rebellious local pain, with a daily average score greater than or equal to 5, on a graduated numerical scale of 0 to 10. The score is defined at the inclusion and corresponds to the pain intensity felt locally by the patient under treatment systemic analgesic with or without co-analgesics. * If analgesics to treat systemic pain is ongoing, it must have been introduced for more than 3 days (according to criteria 3) * If antidepressant treatment is in progress, it must have been established for over a month for a tricyclic and for more than 15 days for other classes of antidepressants. * If an anti-epileptic treatment analgesic is in progress, it must have been established for over 15 days. * Signing of the informed consent form. * Patient able to respond the self-assessment questionnaires (sufficient understanding assessments, proficiency in French). * Patient affiliated to an health insurance plan Exclusion Criteria: * Allergy to morphine or carboxymethylcellulose or history of intolerance to morphine * Analgesic at baseline including systemic morphine to greater than 60 mg equivalent dose of morphine treatment * Fistulated wound * Heavily exuding wound * Wound bleeding (spontaneous bleeding) * Ongoing radiotherapy on chronic wound * Creatinine \> 110 µmol/L, Total bilirubin \> 20 µmol/L * Not communicating patient * Unable to comply with requirement of the protocol (11 days) * Patient pregnant or of childbearing age without contraceptive therapy or lactating * Person deprived of liberty or under guardianship * Only for pharmacokinetic analysis: analgesics at baseline including morphine or hydromorphone or oxycodone or codeine. Fentanyl is allowed