Hello, and thanks for the question. From the looks of the photos, it looks like either a topical skin irritation (maybe from the post-surgical compression garment you may be wearing) or a possible reaction to medications such as antibiotics. However, you can't rule out a cellulitis (skin infection) without an examination.The garments or binders typically worn after liposuction are usually latex free (which some people are sensitive to), but that doesn't mean you can't get irritated from it being in contact with or rubbing on your skin. This could cause some redness, itching and warmth.Antibiotic and other drug reactions usually involve blotches over a wider area, such as the whole trunk, not just the flanks, but could also involve itching.As stated, the possibility of a skin infection (cellulitis) can't be ruled out without an examination. In this case, the skin would be a little thicker in the reddened areas (we call it "induration") and there would be warmth, but usually a little tenderness or mild discomfort also. You may also not feel well, and could be running a temperature. This would need to be addressed more quickly.Finally, sometimes blotches just happen. The blood vessels in the treated areas are dilated during the inflammatory period after surgery, and will soon go back to normal.If things continue, or worsen, get in to see your surgeon.Hope this helps.