Actinic prurigo is a not uncommon sunlight-induced, pruritic, papular or nodular skin eruption.

Causes

The cause for actinic prurigo is unknown, however researchers believe that the 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

Symptoms

AP is characterized by itchy, inflamed papules, nodules, and plaques on the skin. Lesions typically appear hours or days after exposure of the skin to UV light, and follow a general pattern of sun-exposed areas. The face, neck, arms, hands, and legs are often affected, although lesions sometimes appear on skin that is covered by clothing and thus not exposed to UV light, thus making AP somewhat difficult to diagnose.

AP is a chronic disease, and symptoms usually worsen in the spring and summer as the day lengthens and exposure to sunlight increases.

Treatment

Currently there is no cure for actinic prurigo, and treatment focuses on relieving the dermatologic symptoms, by way of topical

Topical

In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...

 steroid

Corticosteroid

Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...

 creams or systemic immunosuppressants

Immunosuppressive drug

Immunosuppressive drugs or immunosuppressive agents are drugs that inhibit or prevent activity of the immune system. They are used in immunosuppressive therapy to:...

.

Prescribed treatments include:

• topical creams such as Tacrolimus
  Tacrolimus
  Tacrolimus is an immunosuppressive drug that is mainly used after allogeneic organ transplant to reduce the activity of the patient's immune system and so lower the risk of organ rejection...
  
   and Betamethasone
  Betamethasone
  Betamethasone is a potent glucocorticoid steroid with anti-inflammatory and immunosuppressive properties. Unlike other drugs with these effects, betamethasone does not cause water retention. It is applied as a topical cream, ointment, foam, lotion or gel to treat itching...
  
  .
• systemic immunosuppressants such as Prednisone
  Prednisone
  Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases and some types of cancer, but has significant adverse effects...
  
  .
• In some cases, Thalidomide
  Thalidomide
  Thalidomide was introduced as a sedative drug in the late 1950s that was typically used to cure morning sickness. In 1961, it was withdrawn due to teratogenicity and neuropathy. There is now a growing clinical interest in thalidomide, and it is introduced as an immunomodulatory agent used...
  
   has proven to be effective in controlling the symptoms of actinic prurigo.

All patients with AP are encouraged to minimize sun exposure, and to use strong sunscreen

Sunscreen

Sunblock is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet radiation on the skin exposed to sunlight and thus helps protect against sunburn...

 throughout the year, and even on cloudy or overcast days, as UVA light, unlike UVB light, is able to penetrate cloud cover and remains constant throughout the day.

Alternative treatment methods might include UV Hardening, Meditation

Meditation

Meditation is any form of a family of practices in which practitioners train their minds or self-induce a mode of consciousness to realize some benefit....

 and/or cognitive behavioral therapy. The U.S. Food and Drug Administration (FDA) has yet to approve these allopathic approaches to medicine, so there remains much to be discovered about this particular illness in the United States.

External links

• http://dermnetnz.org/reactions/actinic-prurigo.html
• http://www.emedicine.com/DERM/topic927.htm
• http://cat.inist.fr/?aModele=afficheN&cpsidt=2157125