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Friday Facts #10 The Traffic-Light Phenomenon

author/source: DrB

                                                        Traffic lights

Scratching, rubbing and picking
the skin is not only provoked by itch: in his famous 1964 monograph "Itching and Scratching: Psychodynamics in Dermatology" Herman Musaph wrote about his observation that drivers held-up at a red light often seem to scratch as they wait for the change to green. Hence was born the idea of The Traffic-Light Phenomenon.

Frustration, puzzlement and boredom
are associated with scratching. Scratching is, it seems, a tension reliever, on a continuum perhaps, from a comforting touching and stroking of the skin, through to cutting into the skin with a blade. Generally we can talk about itch scratching, and habit scratching - some habit scratching is instinctive, and some is more emotional.


The cartoonist knows we all associate scratching the top of the head with thinking: in 1985 Jeffrey Barnard asked "Does thinking itch?". Musaph had given previously ample clinical evidence that psychogenic pruritus - emotionally caused itch - is real enough. Yet, it remains important to recognize there is a lot more to scratching than mere itching.  

Barnard adapted the maxim of Descartes, coming up with: "I think, therefore I scratch. I scratch, therefore I am." Certainly working with a behavioural approach to help people with atopic eczema over many years, it has been striking to realize how much scratching, and not itching, links the skin to the rest of life.

Scratching and itching can both be caused by emotional factors,
but scratching on it's own is a great tension reliever.

Itching and Scratching - Psychodynamics in Dermatology
Herman Musaph 1964 Karger

Does thinking itch?
Jeffrey D. Bernhard
The Lancet - 9 March 1985 ( Vol. 325, Issue 8428, Page 589 )