Children: Betamethasone belongs to the family of medications known as corticosteroids. Children may be more likely to experience side effects (e.g., slowing down of growth, delayed weight gain), especially if large amounts of this medication are used for long periods of time. The use of this medication by children should be limited to the smallest amount that will be effective for the shortest period of time. Discuss the risks and benefits of the use of this medication by children with your doctor.. Betaderm: Betamethasone valerate belongs to the class of medications called topical corticosteroids. It is used to treat skin irritation and itch caused by skin conditions such as eczema, psoriasis, contact dermatitis, and seborrhea. It works by reducing redness, inflammation, swelling, and irritation of the skin.. How to use Betaderm Cream. Use this medication on the skin only. However, do not use it on the face, groin, or underarms unless directed to do so by your doctor..