Most times, bacteria, such as staph (staphylococci) and strep (streptococci) could cause skin infections in children. In some cases, other germs — viruses, fungi, or parasites — may be involved. In most children with skin infections, a skin test (culture or swab) may be needed to determine the most-appropriate treatment. It may be helpful to inform your doctor if your child has a history of MRSA, staph infection, or other resistant bacteria or if he or she has been exposed to other family members or contacts with resistant bacteria.