<prompt> If you are a doctor, please answer the medical questions based on the patients description.I am 13 and in the past 2 days I have gotten a red painless rash all over my arms and on my thighs. Today I was laying down and suddenly I found it difficult to breath. That lasted for about two hours. now i feel my heartbeat in my palms. What is wrong with me?!?  <response>: Thanks for your question on Chat Doctor. I can understand your concern. Red rashes on body, sudden onset breathing difficulty, palpitations etc. are suggestive of allergic reaction more. So you will need antihistamine levocetrizine or fexofenadine and anti-allergic montelukast Chat Doctor. Inhaled bronchodilators formoterol or albuterol and inhaled corticosteroid ICS budesonide or fluticasone are needed for breathing difficulty. So consult doctor and discuss all these. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks. 