Question: We recently saw a young patient who presented with small, raised bumps on her ankles and feet. The parent said the child had recently been wading in a pond by their home. The pediatrician diagnosed the patient with clam digger’s itch. Is there a code for this, or should I just code the rash? South Carolina Subscriber Answer: The code for this is B65.3 (Cercarial dermatitis). Clam digger’s itch is caused by parasites that inhabit warm, shallow water. The condition produces a rash comprised of small, raised bumps, and sometimes even welts or blisters, on areas of the skin that have not been covered. The parasite larvae are called cercariae, which is why the more formal name is cercarial dermatitis.