Is sun sensitivity permanent after IPL?

Sorry to hear about the PIH! It seems somewhat strange to me that you are a month out from IPL and still having sun sensitivity. While we usually use IPL to reduce hyperpigmentation, you should be healed within 7-10 days. To still have residual effects is unusual. The good news is that PIH will go away if you sun protect carefully after several months. PIH is different from a tan. More of a hyperreactivity of your melanocytes to the trauma. I would return to whomever did your IPL. You should be able to use a topical such as hydroquinone to fade and stabilize the PIH. 

Sun sensitivity after IPL is not a permanent issue. After treatment, we advise being more cautious in the sun because the skin is healing after treatment and because we don't want you to have a tan before having your next treatment.

Thanks for your
question and sorry you are having difficulties post IPL treatments – one of the
best treatments out there for photodamage that has been developed. People
develop PIH for a variety of reasons, some of which are related to the
treatment settings or lack of skin cooling; others are related to receiving sun
after the procedure which should be minimal following IPL treatments. These
treatments should always be under the auspices of a board-certified
dermatologist or plastic surgeon and a proper skin care routine should also
accompany the IPL treatments – I am not sure if that was the case here as you
do not mention any. For now, adding a skin lightening agent and the proper use
of sunscreen will help the PIH go away faster than doing nothing. We tell
patients to avoid the sun after IPL treatments to avoid problems. Certainly
after you are finished with the IPL treatments you are having, you still need
to be careful in the sun, but there is nothing to suggest that IPL’s will have
any permanent sun sensitivity issues. The more you are in the sun following
these treatments, the more photodamage will occur, which will make your skin
return to what it looked like before the IPLs in the first place. We use IPL
and maintenance IPLs to give you a nice rejuvenation effect and then to keep it
that way. Protect your skin, go to the right provider, and have appropriate
follow up and you should do just fine.