I am not actually worried but simply curious. When petting with my boyfriend and getting in contact with his sperm, my skin turns slightly red where his cum touches me. Am I allergic, or is there perhaps any other explanation? I am 24 years old and female.

1) This is in reference to your Missed periods Q&A. Another cause of missed or late periods is PCOS (polycystic ovary syndrome). A lot of health care providers don't seem to be aware of this syndrome. In this syndrome, missed or irregular periods are caused by unusual hormone levels, sometimes in combination with insulin intolerance. Because missed and irregular periods cause scar tissue build-up in the uterus (which may cause endometrial cancer) and may cause infertility, it is important that your readers know to ask their health care provider about this syndrome. There are obviously other symptoms and complications, but I just thought that I might mention it to you so that you might read up on it for your readers. Thank you.

2) I was recently diagnosed with polycystic ovary syndrome (PCOS). I'm only 17 and am afraid that this will affect my chance of having children. Should I worry? Also, I know birth control pills will help me regulate my period, but if I take them, will it stop the effects PCOS has on me? Like me gaining rapid weight, missed periods, and losing my hair? This is really worrying me. Can you inform me on this syndrome?

Recently I bought a sun protection cream from a health food store. The cream claims to provide sun protection (it's labeled SPF 15) by a plant complex made of PABA, willow bark extract, myrtle and myrtus leaf extract. It says that myrtle and myrtus leaf help protect from both UVA and UVB.

My questions are as follows:

1) Can this PABA complex provide the sun protection it claims (SPF 15 for both UVA and UVB rays)? The reason I am asking this is because until now I had only heard of sun protection by titanium dioxide or chemicals like octyl mexaoxycinnamate (did I get it right?). So I am curious to find out.

2) I notice a slight burning sensation in my eyes after I apply the product on my face. Is it true that PABA is a common irritant? (Since I notice many products proudly claiming PABA-free I wonder if it's really not good for you.)

Please help. I hope this question falls within your realm of expertise. After all, you are the 'know it all' around here, aren't you?

Someone told me that ChapStick was addictive and the way I'm going through it, I believe them. Is it truly addictive? Can I get help?

Ever since high school, I've had very oily hair and skin, but it became worse in college. Now I'm in my mid-twenties and have to shampoo my hair about 10 times each day to get it clean. Then by evening it's already oily again. This isn't my scalp trying to moisturize itself after being over cleaned, because I've tried not washing it completely and it's even oilier the next day.

Are there any special shampoos or medications that help reduce oily skin? I've tried some facial products from my dermatologist, but they haven't reduced the oil production. This is an embarrassing problem and limits the overnight activities I can do, like camping or staying with friends.

I've come down with chickenpox. Should I stay home from classes even though 90 percent of adults have already had it and are thus immune? If I take great care washing my hands and avoiding coughing anywhere but into the crook of my arm, will I be reasonably assured of not spreading it?