Mysterious reaction to sun when Birth Control Pill is not present

I have been taking Desogen brand oral contraceptive for approximately 6 years.  About two years ago I went off for about 11 months.  During that time if I went in the sun even for as little as 20 minutes, I would break out in a rash.  This never happened to me before.  I went to a Dermatologist and was told I had acne.  Since this rash would only occur after exposure to the sun I refused to believe it.  The rash was on my back, chest and stomach and I have never been prone to acne in all the 25 years of my life.  I returned to the same Dermatologist after a break out and explained to him that I knew it wasn't acne.  He then diagnosed me with Polymorphis Light Eruption.  I went back on Desogen and have not had any reaction to the sun until recently.  I have been using a tanning booth to get a base tan for an upcoming vacation.  I went for two weeks without a problem and then a week ago, which happened to be the week I was on the inactive pills in my Desogen pack, I broke out with just a couple of itchy bumps on my chest and back.  I have been applying hydracortizone and that seems to help.  Now I am back on the active pills, but those same exact bumps that seemed to have gone completely away, come back after I use the tanning bed.  I have descided to discontinue the use of the tanning bed and I will most likely take Benadryl while on vacation.  I was curious to see if you have ever heard of a similar situation in regards to me having a sensitivity to the sun when I am OFF the pill. I know that it isn't uncommon for there to be a reaction when on the pill.  My concern is that I will obviously not be on the pill for the rest of my life and I would like to try and figure out what is causing this reaction.

Thank you,
Merry.

[Alan Rockoff, MD]

I alos have not heard of light sensitivity while off the pill.  I'm afraid your description reminds me of nothing I have seen or heard of before.  Benadryl and a broad-spectrum (UVA-UVB) sunscreen seem like the best ideas.

Best.

Dr. Rockoff