For the past six years, I have suffered recurrent bouts of pityriasis lichenoides chronica. I have had UVB treatment, which has been very effective, but it always comes back.

This skin eruption consists of small roundish, reddish-brown, itchy, scaly, hardened plaques thought to be caused by hypersensitivity to infectious agents. It usually subsides on its own or with help from artificial or natural sunlight, but as yours is persistent it would be good to take an immune-boosting and balancing supplement. Moducare has been developed to increase the body's resistance to disease. It is a daily supplement of plant nutrients, called phytosterols, and nuts, which has been found to help skin conditions such as yours. Take one capsule three times a day before eating. To combat the itching and inflammation try Derma Cal Plus. Moducare (£47.85 for three-month pack) and Derma Cal Plus (£7.95 for 60ml) from the Nutri Centre, 0800 587 2290 or nutricentre.com.

I have had verrucas on both feet for a number of years; they have now become painful. I have heard that tea tree oil can help. Is it safe?

Verrucas are usually a sign the immune system is low. Topical treatment should be accompanied by holistic treatment aimed at boosting immunity. Tea tree oil is a powerful antiviral and antibacterial. It can be used undiluted and is most effective if placed on the verruca itself - take a single drop on a toothpick and drop it into the centre of the verruca. Do this every day until it falls off, which may take up to two months. Lemon essential oil can be used alternately with tea tree. (Organic oils from NHR on 0845 310 8066.)

· Emma Mitchell is a natural health therapist. Before following Emma's recommendations, you should consult your GP about any medical problems or special health conditions.

· Send your questions to Wellbeing, Guardian Weekend, 119 Farringdon Road, London EC1R 3ER. Email: ask.emma@theguardian.com.