Investigate the short- and long-term efficacy and safety of intradermal NSAIDs and lidocaine (delivered through mesotherapy) for the treatment of LE comparing it with empty intradermal injections.

Inclusion Criteria:

• clinical diagnosis defined as pain over the lateral epicondyle provoked by palpation;
• A visual analogue scale (VAS) score for pain greater than 40mm;
• symptoms duration for more than 1 month.

Exclusion Criteria:

• other diseases that can alter clinical evaluation detected through history, clinical examination, ultrasound or other exams for comorbidities such as carpal tunnel syndrome, cervical radiculopathy, elbow arthritis, intra-articular loose bodies, previous elbow surgery or clinically significant or recent trauma, fibromyalgia and major psychiatric conditions;
• VAS score for pain less than 40mm;
• any of the following treatments during the previous 4 weeks before baseline visit: physical therapy, bandage, mesotherapy and local corticosteroid injection or a combination of these: NSAIDS taken during the week previous to inclusion;
• pregnancy;
• allergy to any of the study drugs;
• severely immunosuppressed patients;
• known coagulopathies. During the study period, enrolled patients are not allowed to take oral corticosteroids, NSAIDs or receive any other medical intervention during the treatment period (physical therapy, bandage, mesotherapy and local corticosteroid injection or a combination of these).