The cause for actinic prurigo is unknown, however researchers believe that protein in our bodies may be a cause to the condition also:

•UV-A and UV-B light seem to be the main provoking agents. This observation is supported by the fact that most patients live at high altitudes (>1000 m above sea level), and the condition improves in many patients when they move to lower altitudes. However, some patients who are affected already live at sea level.18,19,27 •Some authors are considering a food photosensitizer or a nutritional selective deficiency as a cause; however, no evidence proves this theory.27

Actinic prurigo (AP) was first described by Escalona in Mexico, in 1954.

Brachioradial pruritus (BRP) is a localized pruritus of the dorsolateral aspect of the arm. BRP is an enigmatic condition with a controversial cause; some authors consider BRP to be a photodermatosis, whereas other authors attribute BRP to compression of cervical nerve roots.

BRP may be attributed to a neuropathy, such as chronic cervical radiculopathy. The possibility of an underlying neuropathy should be considered in the evaluation and treatment of all patients with BRP.

The main cause of BRP is not known, but there is evidence to suggest that BRP may arise in the nervous system. Cervical spine disease may be an important contributing factor.

Patients with BRP may have underlying cervical spine pathology. Whether this association is causal or coincidental remains to be determined.

There is controversy regarding the cause of brachioradial pruritus: is it caused by a nerve compression in the cervical spine or is it caused by a prolonged exposure to sunlight?

In many patients, itching of the arms or shoulders is seasonal. Some patients reported neck pain.

BRP can be linked to the thyroid.

Treatment with lamotrigine has been reported.

Treatment by acupuncture has been reported.