Possibly boils: Hard, painful pimples suggest a localized skin infection usually caused by the bacteria staph aureus. A possible reason it is behind the knee is that your grandson may have eczema which is often behind the knee and makes one more susceptible to staph infections.
Answered 2/29/2016
5.3k views
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.
Ask your question