Sunscreens

Dear Dr.
        For the past two years I have made several trips down to florida.  It seems that everytime I get in the sun the first
couple days I develope a rash.  It usually looks more like sun-
poisoning, but this time it looks more like a rash.  I've often tried to figure out if it was a chemical in the sunscreens or if it was the sun itself.  I really don't think it is the sun because all other times in the sun I'm fine it's only when I come to Florida and pack on the suntan oils when I develope the rash. It's a basic looking rash and it usually develops at bottom sides of my neck around the glands and a little on the arms.  It's not real severe but it does itch.  It does look like a form of dermatitis.  This time my wife got it too.  I am medium skin and she is dark-complected.  We both used tanning oils that contained carrot oil which we thought might be the cause and we used a coppertone spf 45 block also.  Do you know of any ingredients in sunscreens or sunoils that can cause an allergic reaction similiar to what I've described or know what the allergic reaction might be from?
Thank you very much,
                     Derik  

[Alan Rockoff, MD]

Derik:

Lots of people complain to me about the kind of rash you describe, and it's hard to be sure exactly what it is.  As you note yourself, skin coloring doesn't seem to have much to do with it.  I think that in many people it's a form of allergic reaction not to the ssunscreen or the burning rays of the sun, but to the long waves of ultraviolet light that sunscreens don't block.  The remedies are therefore:

1.  Vacation in Alaska.
2. Use a broad-spectrum sunscreen that covers UVA rays (long wave UV): many screens do this, and say so on the label.
3. Try taking an antihistamine like clortrimeton 4mg (OTC) an hour before hitting the beach.  This may make you a little drowsy, but hey--you're on vacation.
4. Wear protective clothing when possible.  I know you don't want to, but you also don't want to itch.
5. Vacation in Labrador.

If these fail, try consulting a dermatologist.

Best.

Dr. Rockoff

PS.  Most people don;t like suggestions #1 and #5.