Hi.. Thanks for the query.. Itchy bumps all over the body can be most probably due to allergic reaction only and the common causes of allergic reaction can be allergy to certain foods or any medication if you take, skin cosmetics and detergents, leather, latex etc.. On the other hand soreness, swelling and infected appearrence of the nipple can be due to infection of the nipple post piercing and can be due to wearing the jewellery that is not made of inert material and can cause irritation and allergic reaction on decomposition.. Sore throat and swollen lymph nodes can be due to throat infection most commonly, however can also be due to allergic reaction.. So first of all consult an Emergency room and get evaluated.. For allergic reaction anti allergics like Benadryl and a steroid shot can be advised. An allergic test can also be done to rule out the cause of allergy.. Secondly for the infected nipple, first of all remove the jewellery that you are wearing, clean the area with antiseptic solution and apply antiseptic ointment over it.. For sore throat, if it is due to infection then a course of antibiotics and anti inflammatory painkillers can be advised along with warm saline gargles and antiseptic mouthwash gargles. Sucking throat lozenges can also help.. Hope this helps.. Regards.