There is no as such any best treatment for eczema, but a good moisturizer and keeping the skin away from the allergens will keep you away from eczema 

The combination of these symptoms might direct that you have a commonly occurring skin problem called seborrheic dermatitis. Health deterioration may result in the appearance of red, irritated skin, flaking of the skin, and hair loss. The chief drivers of these are oily skin, a yeast type that is a natural inhabitant of the skin, and hormones. Moreover, you can use dandruff shampoo that contains ketoconazole or coal tar. When you are bathing, don't go hard on your hair and make sure you don't sunlight your scalp because it can result in difficult and painful inflammation.

Psoriasis is a common skin disorder that causes red, scaly patches. It happens when the immune system overacts, leading to faster skin cell growth. Symptoms include itching and dryness. Treatments include creams, ointments, and medications to relieve symptoms. Remember to moisturize and avoid triggers like stress and certain foods.

Dandruff is a fungal infection and there is not permanent cure for dandruff.