Write an article based on this summary:

Consult with a dermatologist. Use a corticosteroid. Take an antihistamine. Have light therapy done. Have long-lasting spots treated by a dermatologist.
If you have lichen planus, it's important to get care from a medical professional who has extensive knowledge of skin conditions. A dermatologist will be able to diagnose your condition by inspecting the bumps and redness on the surface of the skin or inside the mouth. They can then give you treatment that will minimize the condition. In many cases, you will go to your primary care physician first and then get referred to a dermatologist. Your doctor will likely prescribe you either a topical or oral corticosteroid to treat your skin condition. These are used because they help your body fight the infection.  There can be side effects caused by long-term use of corticosteroids, such as impact on the thickness and color of the skin, so you should use them for as little time as possible. Oral corticosteroids are typically prescribed for lichen planus that has caused sores in the mouth, as the medication will be able to enter the bloodstream and treat the sores. Steroids should only be used for 2-4 weeks. If you have severe itching, your doctor will likely prescribe you an antihistamine to reduce that feeling. They usually come in pill form and are taken daily.  Antihistamines block the chemicals in the body that create inflammation and irritation.  Common antihistamines prescribed for lichen planus may include diphenhydramine, hydroxyzine, fexofenadine, loratidine, and cetirizine. Be aware that taking antihistamines may make you drowsy, so read the packaging and follow the directions and warnings included. Your dermatologist may suggest using light to treat your condition. Ultraviolet light therapies, such as PUVA therapy, can reduce the rash associated with lichen planus.  Light therapy is a process in which the dermatologist puts a light-activated medication on your skin and then they apply ultraviolet light to activate it. You will likely need at least 15 treatments spaced a few days apart to improve your condition.  Talk to your doctor about whether this treatment is right for your specific case of lichen planus. There are some situations, such as if you have very sensitive skin, when it may not be appropriate. As this disease diminishes, it may leave behind dark areas that don't go away on their own. You can contact a dermatologist if you want to eliminate these dark patches. Your dermatologist may be able to use bleaching creams and laser resurfacing treatments to eliminate these spots.