Would you advise people to avoid face creams and other toiletries and cosmetics that contain parabens?
Parabens are preservatives put into face creams to give them a longer shelf life and to prevent contamination with harmful bacteria – they do nothing positive for your skin. Whether or not you use them depends on how you view the two sides of the parabens argument. The main claim against is that they have an oestrogen-like effect (albeit tiny, if it exists at all) that may increase women's chances of developing breast cancer, but the debate on the evidence for and against this claim is still ongoing. I'd recommend you read up on parabens: try the US FDA website and even Wikipedia. Would I advise people to avoid them? I have to accept that they haven't been proven to be harmful, but I'm not comfortable about using them myself. I quite like aqueous cream BP, but if you're buying a commercial product, always read the ingredients first.

I'm 31 and have for six years been taking a daily antihistamine, usually cetirizine, for urticaria, a skin rash. We're now trying to have a baby and I am worried about my reliance on antihistamines. My GP's advice hasn't been helpful. Can you help?The difficulty about advising on drugs in pregnancy, including antihistamines, is that no definitive testing has been done in pregnant humans, so manufacturers shy away from recommending them during pregnancy – this may explain why you think your GP was unhelpful. However, there is no evidence from animal studies that commonly prescribed antihistamines have adverse effects on the foetus (the exception is hydroxyzine, or Atarax). Sedative antihistamines can cause a newborn to be overexcitable, irritable and to shake, so we use non-sedative ones such as cetirizine, fexofenadine or loratadine. Have you tried to find the cause of your urticaria? It may be worth asking for a referral to an allergy specialist.

• Got a question for Dr Tom? Email doctordoctor@theguardian.com