About Karpukarasi Ayyanathan, MD. Karpukarasi Ayyanathan, MD is a pediatrician who practices at Linden Pediatric Group, PA located at 517 Rahway Ave in Elizabeth, NJ 07202 (Union County). Dr. Karpukarasi Ayyanathan has 15+ years of experience in pediatrics. Education. Karpukarasi Ayyanathan, MD earned a degree of a Doctor of Medicine..