At What Age Can One Go for EPL or IPL?

I have seen skin damaged by IPL treatments. I had an IPL in my office and quickly determined lasers are far safer and more effective for hair removal and skin rejuvenation. For rosacea or broken veins of the face use the V-beam laser. It is the gold standard for rosacea and facial veins

The tattoo will be slightly lighter, as the IPL destroys and "lifts" darker pigment molecules such as the ones found in your tattoo.  

I would discontinue the tetracycline and duac cream at minimum 1 week before your IPL, and ideally even 2 weeks. Best to speak with your dermatologist about available laser treatments such as Isolaz for acne.

Desonide and other topical steroids if used chronically can cause telangiectases or broken capillaries to develop on the skin; thankfully there are now non-cortisone options for eczema and itching of skin, best to speak with your dermatologist about this. As for IPL, this would be a safe and...

Interesting and amusing question. There is no data to suggest that slapping the skin is good for collagen, although the discomfort of IPL does "slap the skin", it slaps it with tremendous heat which seems to help tighten the skin a bit....a fractionated laser would be better at tightening the...

On different areas of the body hair grows in at different rates.  I would advise you to keep to the schedule to have the best results.  Different areas of the body are advised at different intervals.  For example you can wait longer in between treatments for hair on the legs than facial hair.