I understand you're dealing with skin itching. Itching can occur when your skin becomes dry and rough, often due to not drinking enough water, using harsh soaps, or cold weather. To manage it, make sure to drink plenty of water, apply moisturizer gently, and avoid harsh soaps. Also, protect your skin from the cold by wearing gloves and scarves.

You may have a combination of shiny skin, hyperpigmentation, pimples on your forehead, and spots on your cheeks. Overactive oil glands are a magnet for pimples which consecutively leave dark marks. Stress, hormones, and your diet could all contribute to making it severe. Tanning or irritating your skin might be responsible for brown spots. To fix your issue, gently clean it every day using cleansing products; you can get some over-the-counter drugs meant for treating acne then apply them as instructed, and protect it against the sun by wearing sunscreen all the time.

The contact dermatitis can last a long time. It depends upon the nature, frequency and duration of the exposure to the allergens. If the exposure to the allergens continues it might take very long time. If the exposure to the allergens is stopped then it will be recovered quickly.