<s>[INST] my 3 year old son has a constant bruise on the middle of the lower back. it is usually a yellowish color but today when i looked at it it has red spots. also when feeling it when he is standing up it feels like a bumb. but with him bending over its a semi large bulge [/INST] Hi, Skin conditions are best diagnosed only after seeing directly. I suggest you to upload photographs of the same on this website, so that I can guide you scientifically. Please revert back to me with images so that I can guide you better. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr Sumanth Amperayani, Pediatrician, Pulmonology </s>