Can IPL make brown spots on hands worse? (photos)

Thank you for your question JTB TX. I understand your concern.
IPL is a great treatment for facial rejuvenation. It works well for pigment on and off the face. For my patients I recommend a series of 6 monthly treatments followed by one maintenance treatment every 3 months thereafter. Applying retin-A can make the skin red and peeling. If this occurs I recommend that my patients back of and use less of it and/or use it less frequently. For my patients I prefer products such as hydroquinone and vitamin C for the hands. Please consult with a doctor for specific recommendations. Good luck!

Thank you for your question and for submitting photos.  After a typical IPL treatment, dark spots on the skin typically become darker - like coffee grounds sprinkled on the skin.  The dark spots typically flake off over the next few days to weeks - this process can take up to 3-4 weeks on the hands.  I'm glad you're using sunscreen daily - that's a great idea in general and especially after any laser or light procedure.  I don't typically recommend using Retin A immediately after IPL, as it can increase irritation and redness and delay the healing process.  
Looking at your photos, it appears that the brown spots on your hands are a combination of lentigines (commonly known as sun or age spots), which respond well to IPL, and seborrheic keratoses, which do not.  You may need a touch-up treatment with liquid nitrogen or a different laser to address the seborrheic keratoses in the future.  I would recommend discussing your treatments with a cosmetic dermatologist to determine the best treatment plan for you.