Itchy red rash and welts on legs and back

[pakesboy]

Yesterday, I had a lot of itchy feelings all around my body. The main area I was scratching was my back, so I looked at my back and there was a large red rash covering my upper back and right shoulder/upper right area. I put some sarna lotion on it and it eased the itching sensation but it still lingered, but the mostly went away. Throughout the day, I had noticed odd welts popping up on my legs in patches (like 3-4 in each patch) and there were 4 different patches, 2 on each thigh and 2 on each leg. These welts were really itchy and I had the same jumpy-itchy sensation throughout different parts of my legs and back. I had trouble sleeping due to the sensation and I couldn't fall asleep until 2AM. This morning, the welts had gotten a little smaller and some had disappeared, but now they were small ones spread throughout my legs. I put more of the sarna lotion and it eased the itching sensation again. I noticed the rash on my back had gone away last night, but now it's back but not as widespread. I still have the same itching feeling on my legs and back and I can't get rid of it.

What could this be? How do I get rid of the itch? I'm a 12 yr old guy if it matters, and my mom has no idea what this could be (me either obviously).

Back rash: http://imgur.com/fzBqZU7
Raised leg/thigh welts and red patches:
http://imgur.com/FlmFysL
http://imgur.com/evQm0b8
http://imgur.com/n0qc8ar
http://imgur.com/IcRwfRN
http://imgur.com/VysKXxQ

[Dr.Saiyan]

Hi Anthony! Welcome to dermatalk. Sorry for your condition. Your condition seems like acute urticaria to me. You may to be allergic to different factors including new food added to your diet, recent medicines,infection, external factors like heat ,cold, pressure, any substances that have come in contact with your skin or inhaled, insect bite or stings etc. I suggest you to see the dermatologist and get some oral antihistamines like loratidine for week or two along with some calamine lotion for external application. Besides this as far as possible try to explore the cause and eliminate it.hope you keep us dated about your condition.

[pakesboy]

Thanks! I took both claritin and put some calamine lotion on my legs, the rash has basically disappeared and the welts are gone!