Asian Journal of Case Reports in Medicine and Health

De Quervain’s tenosynovitis is a common inflammatory condition of the wrist and thumb that causes pain and functional limitation. Therapeutic ultrasound is frequently used in conservative management; however, some patients are unable to tolerate conventional contact ultrasound due to localized hypersensitivity. Underwater ultrasound therapy may offer an alternative method of ultrasound. 42-year-old male software professional with a two-month history of radial-sided thumb pain and difficulty gripping objects presented with features consistent with De Quervain’s tenosynovitis. Previous conservative treatments provided only temporary relief, and the patient was unable to tolerate contact ultrasound due to pain hypersensitivity. Underwater ultrasound therapy was administered using a 1 MHz frequency at 1.0 W/cm² in continuous mode for 10 minutes per session for a total of 10 sessions. Pain intensity measured using the Numerical Pain Rating Scale (NPRS) reduced from 6 at baseline to 3 by Day 10 and reached 0 by Day 30. Functional outcomes assessed using the Patient-Rated Wrist Evaluation (PRWE) showed marked improvement. PRWE pain scores reduced from 30 at baseline to 7 by Day 15, and 0 by Day 30. Functional scores for specific activities improved from 28 to 0, and usual activity scores improved from 21 to 0 by Day 30, with sustained recovery at follow-up. This case report indicates that underwater ultrasound therapy may be a safe and well-tolerated physiotherapy intervention for achieving significant pain relief and functional recovery in patients with De Quervain’s tenosynovitis who are hypersensitive to conventional ultrasound applications.