HI. Welcome to HCM From your description and the location of the rashes, you seem to have seborrheic dermatitis, affecting the oily areas of your body, similar to dandruff on the scalp. Even if you do not generally have dandruff, oiliness of scalp and hair could have caused the rashes on back and chest. Change in climate, sweating, certain hair products etc, can aggravate the problem. Dry skin and rashes on the arms, elbows etc can indicate an eczema or allergic nature, often seen along with seborrheic dermatitis. For your hair try using an antidandruff ketoconazole shampoo twice a week and a similar soap for the body which will reduce the problem. Do not apply oil, gels etc for long periods of time. As for rashes on your arms and severe rashes on your body use a steroid cream lightly,like mometasone for 7-10 days. Always keep your skin moisturized immediately after bath or shower with a good lotion like cetaphil, or nivea. Your skin type is prone to dryness and allergies, so keep it free from harsh chemicals, fragrances. Use mild glycerin or syndet based soap bar for bath over these areas. Start with these treatment for a week or so. If you notice no change, or increase in rashes be sure to consult a dermatologist and get a confirmed diagnosis. they can also rule out fungal infections, or do tests required to check for specific allergies, etc. Hope this helps.