Does thinking itch?
“Does thinking itch?” asked US dermatologist Bernhard in a letter to the Lancet in 1985. He referred to “the observation that people often scratch their heads when thinking or perplexed”. He noted that the Dutch psychiatrist Musaph had previously written in 1964 how scratching can occur without itching with certain mental states, including frustration, irritation and boredom - as when driving a car and being held up by a red light. Musaph coined a term for this: “The Traffic Light Phenomenon”. In 1996 the British anthropologist Dunbar wrote of the social significance of grooming, and how self-grooming can be an indication of stress and depression.
When assessing scratching in atopic eczema it is important to distinguish scratching, an action, from itching, a feeling, as the terms are often used as if they refer to the same thing. Reviewing 50 consecutive patients who had been successful using The Combined Approach in treating their previously chronic atopic eczema, we found, before treatment, a mean 60% of scratching was attributed by the patients to itching. The remainder was due to habit, and mental state.
The itch-scratch cycle, as it is usually described, is a notorious two-way “vicious” circle. The importance of how scratching can provoke itching is now drawn particular attention to by studies published in the British Journal of Dermatology that clarify the chemical pathways involved.
The Combined Approach recognises habitual scratching exacerbates and perpetuates atopic eczema. The diagram above reverses the usual description of “itch-scratch” to “scratch-itch” in order to emphasise the role that scratching plays and to emphasise the relevance and importance of including habit reversal in the management of chronic atopic eczema.
Bernhard JD (Ed.)  Itch: Mechanisms and Management of Pruritus. New York: McGraw-Hill, Inc
Musaph H  Itching and Scratching: Psychodynamics in Dermatology. Basel: Karger
Dunbar R  Grooming, Gossip and the Evolution of Language. London: Faber
Bridgett CK, Roberts N.  Cognitive therapy of itch and scratch in atopic dermatitis ‐ a review of 50 cases. Proceedings of the 6th International Congress of European Society Dermatology & Psychiatry. Amsterdam.
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Staughton RCD et al B J Dermatol  https://doi.org/10.1111/bjd.19049