Hi and welcome to HCM From your history and description it does seem to be an allergy, esp based on the areas affected. Summer/spring allergies are fairly common due to more dust, pollen in the air, as well as sun. Since you are unable to narrow down the cause, I would advise you to take precautions during this season. Wear comfortable cotton clothing, covering as much skin as possible. Avoid mid day sunexposure. Always use a sunscreen. Wash hands, face when you come back from outdoor activity. Shower with warm water and apply a good moisturiser immediately after like Cetaphil DAM or an intensive moisturizer. AVoid fragrances and strong chemicals in soap, lotions. When you have active rashes try to avoid commonly allergy causing items like nuts, seafood etc. Also during rashes take an antihistamine tablet once daily like fexofenadine and apply calamine lotion over the area when irritation occurs. In case of severe redness or actively spreading rash in the summer, use a fluticasone cream for about a week over the rashes and stop. Continue the other tips advised. You can consult a dermatologist regarding certain skin allergy tests and blood tests which can point out the substances you are allergic to. Hope this helps.