In regard to your question, you might be having one of the following conditions like Eczema, heat rash, Food allergy,fungal, bacterial, or viral infections. However in your case it probably looks like ringworm infection known, as Tenea Corporis.It is mainly a fungal infection. It presents with the above-mentioned symptoms. Most of the rashes are not dangerous. I would suggest you to get complete blood tests, skin patch test and lymph node FNAC to confirm the cause. The itching can be controlled by using antihistaminic drugs like Tablet cetirizine at bedtime for 3 days and supplement with moisturizing lotions. You can also use an antifungal cream like Lotrimin cream; Cruex cream can be applied twice a day for 2 weeks. If it does not subside by then you could consult the dermatologist.