Hi ! It is not necessary to have a weak immune system to have repeated cough and cold
. This is a seasonal problem and most people normally get affected with viral cough
and cold which usually are self limiting. The reason for your piercing getting infected is the metal which is a foreign substance and reacts with the skin.Many artificial jwellery are made of metals which react badly to the skin. Reactions with gold ornaments are not frequently seen unless they are mixed with other metals. The reaction of the metal with the skin is mostly not related to the immune system of the body. It is just a foreign body reaction. Repeated piercings can also result in hypertrophic scar
. So take care. Thanks.