Wrinkles are caused mostly by ageing and exposure to the UV rays in sunlight. Smoking also damages the skin. There are two prescription-only preparations that can help smooth out skin. They both contain tretinoin, a chemical related to vitamin A. Retinova is a cream (not available on the NHS) for sun-damaged skin. Retin-A contains the same ingredient but is for acne (it can be prescribed on the NHS). Tretinoin can cause redness, peeling and discolouration.
I want to give my children fluoride supplements to strengthen their teeth but I am worried about the side-effects. Is there any risk?
Ask your water authority how much fluoride is in your supply. If it's more than 0.7 parts per million, there is no need for supplements. In areas with little fluoride in the water, you can use fluoride tablets. Too much can cause fluorosis, which leads to permanent teeth discolouration.
I understand there is a new coil that can treat heavy periods. Does it work? Where is it available?
Intra-uterine coils (IUCDs) have a reputation for causing heavy periods, but one manufacturer has produced one that releases a tiny amount of progesterone as it sits inside the uterus. This combination of coil and hormone is highly effective both as a contraceptive and as a way of lightening periods. The coil is called Mirena and it can be used for up to five years before it needs to be replaced. However, it can take several months before it is fully effective in reducing blood loss. Also, it may not be suitable for young women who have not had children. Mirena is available on the NHS, from GPs or family planning clinics. For further info: www.womens- health.co.uk.
I've always used aspirin as a painkiller, but recently found out it is no longer recommended for children. Why?
Aspirin has been taken by millions of people (including children) without harmful effects. But paediatricians now believe that a rare condition, called Reye's Syndrome, can affect children who have taken aspirin. It can lead to brain damage and liver failure. Although the likelihood of this is exceedingly small, children under 12 should not be given aspirin. Paracetamol and ibuprofen are good alternatives.
Please send your questions to Question of Health, `The Independent', 1 Canada Square, Canary Wharf, London E14 5DL; fax 0171-293 2182; or e- mail them to email@example.com. Dr Kavalier regrets he is unable to respond personally