Q. How long can sunscreens last? (Weeks? Months? Up to a year?)

Answer: A good rule of thumb is that most topical medications lose approximately 5% of their effectiveness after one year. Some actually have expiration dates on the label. I would recommend replacing with a new bottle after one year.

Q. I have been unable to find a sunscreen for my face that does not cause me to break out in a red rash. Sunscreens work fine on my body, but I have nothing to protect my face with.

Can you recommend a product that will not cause breakouts or allergic reactions? I have tried all the oil free, non-pore clogging, perfume free products I could think of. Please help. Thanks.

Answer: When it comes to "acne" type breakouts usually "gel-based" sunscreens work the best. They don't contain the oils that lotions and creams contain that cause your skin to break out.

For the "allergy" component, I would recommend a PABA free sunscreen.

Q. After a rather bad case of sun poisoning 6 months ago, when the rash cleared I was left with 7 or 8 small bumps (size of the head of a pin) on my chest. I had a biopsy done and the results came back "pre-cancerous".

I had them frozen off a month ago. Now it looks like the freezing has caused more bumps to emerge right over the frozen area. They are sensitive to the touch and itch at times.

Question: Should I go back and have them frozen again? I am very self-conscious about them and cannot wear any lower neckline clothes.

Answer: A couple of possibilities. 1) Either the lesions were not adequately frozen and some remain which need further treatment or:

2) The area healed with hypertrophic or keloid scars (usually present as red, slightly tender or itchy firm bumps) which can be treated with cortisone injections. Either way I recommend a re-evaluation by a dermatologist.