Description of Intervention
Desensitization is a daily routine of retraining the nervous system in the hand to process sensory information, after damage through peripheral nerve injuries, tendon injuries, burns, frostbite or chemotherapy-induced peripheral neuropathy.1 Often, tenderness and hypersensitivity of scar begins at 1-2 weeks after injury or surgery and can last weeks, months or even years. It is important to bombard the involved area with sensory stimuli with a routine of friction massage, scar mobilization, light stroking, and percussion. For desensitization to be effective, the patient should work with the therapist and at home on prescribed daily exercises.2 Often the exercises will involve aspects of the patient’s occupation and/or home life. The goal of this technique is to make scars and involved areas less tender and sensitive and less overly reactive to touch and pressure. It is normal for these techniques to leave the scar or involved area uncomfortable or numb for a short while after its treatment sessions.
Indications for Intervention
Hypersensitivity can be caused by a surgery or by injuries such as peripheral nerve injuries, flexor tendon injuries, bone injuries or hand burns. The patients with brachial plexus nerve injuries may experience higher pain levels than those with flexor tendon injuries.3 In patients with chemotherapy-induced peripheral neuropathy, the change in sensation will not be localized to one nerve; however, hand therapy techniques can still be used to retrain the nervous system.2
Diagnosis
- Ask for the patient’s medical history, including any recent hand injuries, second degree burns or cancer treatment.
- Measure the patient’s pain intensity. The Illness Intrusiveness Scale, Pain Disability Index and McGill Pain questionnaires may be used.3
- Evaluate the patient’s hypersensitivity to different textures, immersion particles and vibratory frequencies.4
- Measure skin temperatures due to cold intolerance. Ask for the patient’s perspective of how this intolerance influences daily activities.5
- In subsequent visits, after 8 weeks of therapy, check for hyperaesthesia, which is a feeling of “pins and needles.” This can be the first sign of nerve rehabilitation.6
Intervention Options
The quality of sensory recovery depends on the type of nerve damage, survival of nerve cells, the type of injury, the level of lesion, the patient’s age and comorbidities.7 In most cases, hand therapy should start almost immediately after surgery or other treatment.4 When therapy begins early, there will be more possibility of retraining the central nervous system to work with the hand, to return to daily activities.1 The stages of recovery are the anesthetic stage, in which there is a risk of burns from everyday objects, the hyperaesthetic stage, of sensory regeneration, and the hypoaesthetic stage, in which sensation returns, usually to a reduced degree.
Desensitization techniques include massage, percussion, heat, compression, contrast baths, scar mobilization, traction massage and utilizing a series of textures (soft and smooth to hard and rough). When using contrast baths, it is important not to apply extremes in water temperature.4 Desensitization techniques may imitate the patient’s home and/or work activities. For example, a carpenter could work on a small woven chair.6
The recovery of sensation in a hand often takes at least 3 to 4 years, and the sensation may never reach the extent of the patient’s pre-injury abilities. In addition to hand therapy, the patient may need counselling and psychological support.6
For desensitization caused by superficial second degree burns, first check the depth, location of the burns and fluid replacement. Traditional therapy can be used, but there may be more improvement in patients if electrical stimulation is added to traditional therapy.
Associated Diagnoses
- Peripheral nerve injury
- Flexor tendon injury
- Second degree burns
- Frostbite
