You have not mentioned the reason for the rashes or the black marks on your back. Is it due to chicken pox or an allergic reaction to a certain cosmetic? How long has it been for? Rashes on the body can occur due to several reasons like allergies to certain foods that you eat certain chemicals in cosmetic skin care and hair products, dandruff, etc. Do not scratch the affected skin where you have the rash as it would the spread to other areas of your skin. Scratching the affected area also ruptures the skin causing inflammation and black marks. If you do not know the reason for your rash then you must see a dermatologist and get a skin check up. Self medicating without knowing the reason of the rash might cause further complications and will make your problems worse. You may try the following home remedies if you feel that the rashes and black spots are a minor skin problem and not caused due to an allergy to certain food or cosmetic.
Take curd made from low fat or skimmed milk and add a few drops of lemon juice to it. Apply this on the affected area. Leave on for about 20 minutes and then wash off with cold water and pat dry. Curd and lemon have a bleaching effect on the skin and help to reduce the black marks. You may also eat low fat curd and drink buttermilk.
If the rash is due to excessive drying of your skin then you may apply olive oil mixed with a few drops of lemon juice to the affected area. Olive oil will sooth the dry skin and lemon will control the rash and reduce the blemishes.
Apply pure organic aloe vera gel mixed with a few drops of vitamin E oil to rashes and spots on dry skin and plain aloe vera gel if the skin is oily. Aloe vera has naturally powerful antibacterial properties and will treat the rash effectively. It will also help to sooth the skin and fade the marks. Vitamin E oil will help to diminish the spots and moisturize the skin.
Take equal quantities of sandalwood powder and turmeric root powder. Make a paste of these using pure rose water. Apply this on the affected area. Leave until dry and then wash off with plain water and pat dry with a soft cloth. Then apply pure rose water directly on the affected area with a cotton ball and let dry naturally. This will help to fade off the marks quickly and will also control and treat the rashes as turmeric has powerful antibacterial properties.
answered by G M