Hello, Thank you for posting your query. There could be number of conditions presenting with red bumps and irritation. Since you are giving the history of rapid spread of lesions and associated irritation i would like to put a tentative diagnosis of insect bite. Treatment for the same is pretty simple enough. You should take a short course of oral antibiotics like cefadroxyl for 5 days to prevent or heal any underlying secondary infection. Apply a cream containing mometasone and fusidic acid twice a day gently over affected areas. Add oral antihistamics like avil to your treatment to relieve itching. I guess this will suffice for the cause. wish you best of health and take care. Thank you