Below is an instruction that describes a task. Write a response that appropriately completes the request. ### Instruction: Recurring severe petechiae on 5f, multiple doctors confusedMy daughter 5F Caucasian. No significant medical history. She has had recurring petechiae on her elbows and occasionally knees for approximately 3 months. She is otherwise very healthy and full of energy. The petechiae occur mostly while she is at school, always on predominantly left elbow with occasional right elbow and knees. They do not occur every single school day, but most days with varying severity.She has visited multiple GPs and a pediatric hematology specialist; none of these have been able to find an explanation. She has had multiple complete blood counts, clotting factor tests, and other bloodwork taken. Platelets, red blood cells, white blood cells completely within good normal ranges. All other tests returned completely normal findings aside from marginally low ferritin and fibrinogen. The hematologist said neither of these were of concern to her.Some images of the petechiae on various days recently:https://imgur.com/a/OHKjDtlAny ideas would be very much appreciated.EDIT: Sorry, I forgot to include this information! They are non blanching and totally flat. Non itchy. They go away within about 24 to 48 hours, only for new ones to appear.The doctors have generally identified them as petechiae, but can't determine a cause.. ### Response: Sometimes skin biopsy can help with to diagnose conditions such as this.They looks raised and scaly. Can you run your finger over them with your eyes closed and feel them?Petechiae are generally considered to be less than 2 mm, and these are larger than that. I wouldn't describe it as petechial. Maybe purpura, but I can't tell if it's blanching.Does it itch?Pediatric psoriasis can look similar to this and occur on the extensor surfaces..