Chronic itch is a very unpleasant condition which occurs often in general practice and can be mysterious and hard to treat. We call it pruritus, from the Latin word for itch. On one hand scratching an ordinary itch is one of the great pleasures of life. Who doesn’t like having their back scratched especially if it’s in exactly the right spot with exactly the right intensity for exactly the right time? “Up a bit…over to the right…just under the shoulder blade…that’s it…Aaaaah!”
But when itch is intractable and scratching makes it worse people can really suffer. Dante described it as one of the torments in his Eighth Circle of Hell, and I have some patients who would probably agree with him. It certainly warrants investigation and a careful analysis of possible causes. The simplest diagnostic system is to divide it up into:
Primary skin conditions, especially anything that inflames the skin, such as psoriasis and eczema. We might include in there chronic urticaria which is like hives that keeps relapsing.
Arising from the internal organs such as liver or kidney disorders and some blood conditions.
Medication side effects
Psychological and neurological conditions
Others, such as the elegantly named Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPS).
I have to say that there are cases which don’t fit into any of these categories, especially in the elderly where dryness and thinning of the skin appear to be factors. Usually itch is worse when the body is heated, such as after a shower or when bundled in bed at night. It can significantly affect sleep quality and be very debilitating.
Our therapeutic approach depends on the diagnosis, if there is one. Most people end up cycling through a variety of antihistamines, steroid creams or tablets, moisturisers and specific itch remedies like crotamiton (“Itch-Soothe”). I used to have a special recipe that the chemist made up with menthol and phenol in it, but it only helped temporarily by cooling the skin. When all else fails the specialists do have some high-powered drugs which suppress the immune system and can convert the condition from terrible to bearable. In the elderly the mainstay is intensive moisturisation which is achieved by avoiding ordinary soap, which tends to dry the skin, and applying emollients liberally. Otherwise you might have to approach somebody with the classic offer – “You scratch my back, and I’ll scratch yours!”