Notalgia paraesthetica is a condition where itch and/or changed sensation arise in the areas of skin just below the shoulder blade on either side of the back.
Visible changes arise from rubbing and scratching the affected area. These include hyperpigmentation (brown mark), hypopigmentation (white mark), lichen simplex (a type of eczema) and scarring. There may be changed sensation when this is tested for with pinprick, cotton wool or heat and cold. There may be reduced or absent sweating in the affected area.
Cause of notalgia paraesthetica
The nerves which supply sensation to the upper back emerge from the spinal cord (2nd to 6th thoracic segments) and run a long course up through the thick muscles of the back. They make a right-angled turn before reaching the skin. The nerves appear to be vulnerable to compression or traction.
Initial injury to the nerves may include:
Treatment of notalgia paraesthetica
Treatment is not always necessary, and it is not always successful. Effective measures may include the following:
- Cooling lotions as required (camphor and menthol)
- Capsaicin cream – this depletes nerve endings of their chemical transmitters
- Local anaesthetic creams
- Amitriptyline or other oral tricyclic at night
- Transcutaneous electrical nerve stimulation (TENS)
- Gabapentin or pregabalin
- Botulinum toxin