As a result of dehydration, hair loss is seen in many people and is often permanent. The scalp needs to be well hydrated for healthy hair.   Dehydration can cause hair loss and sometimes this may not be reversible. Oral rehydration therapy is a treatment option available to patients of prolonged diarrhea or vomiting. It is not used as a prophylactic measure and should not be used as the sole treatment for dehydration.   A balanced diet and fluids are needed to drink lots of water for best results. Oral rehydration solutions contain electrolytes, sugar, salts, vitamins and minerals that help restore fluid balance.   Corticosteroids are a type of medication used to reduce inflammation and are sometimes prescribed for scalp skin lesions. In such cases, corticosteroids may be injected directly into the hair follicle to kill bacteria and promote wound healing. A possible side effect is thinning of the hair in the area that had been treated.