Richard: I?ve got an eight-year-old son. Initially he came out in quite a number of boils and later on he started getting sores on his head and after a while, trying to treat these sores, they just became worse and worse, like scabs. We took him to a dermatologist. They diagnosed that he had psoriasis. I asked them what the cause of psoriasis is and they told me anxiety.

Prof Harry: No, that?s not true. Anxiety may make it worse but the fundamental cause of psoriasis is unknown. There is though a genetic element. In your family is there anybody with psoriasis?

Richard: Not to my knowledge.

Prof Harry: But there are a number of things that can aggravate psoriasis — anxiety could be one of those but because we don?t know what causes it, we don?t know a cure.

Richard: Could the boils be linked to it?

Prof Harry: Yes, sure. What happens with these chronic skin conditions like psoriasis is that they can become complicated by infection. Especially if you have been treating them with cortisone.

Richard: They?ve given us cortisone cream and that seems to make it worse.

Prof Harry: That?s exactly what I?m saying to you. One of the complications of cortisone applied to the skin, especially in large amounts or in high concentrations for any length or time, it disturbs the immune system and results in the development of these infections.