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The imagined itch: brain circuitry supporting nocebo-induced itch in atopic dermatitis patients.
Allergy. 2015 Nov; 70(11):1485-92.A

Abstract

BACKGROUND

Psychological factors are known to significantly modulate itch in patients suffering from chronic itch. Itch is also highly susceptible to both placebo and nocebo (negative placebo) effects. Brain activity likely supports nocebo-induced itch, but is currently unknown.

METHODS

We collected functional MRI (fMRI) data from atopic dermatitis (AD) patients, in a within-subject design, and contrast brain response to nocebo saline understood to be allergen vs open-label saline control. Exploratory analyses compared results to real allergen itch response and placebo responsiveness, evaluated in the same patients.

RESULTS

Nocebo saline produced greater itch than open saline control (P < 0.01). Compared to open saline, nocebo saline demonstrated greater fMRI response in caudate, dorsolateral prefrontal cortex (dlPFC), and intraparietal sulcus (iPS) - brain regions important for cognitive executive and motivational processing. Exploratory analyses found that subjects with greater dlPFC and caudate activation to nocebo-induced itch also demonstrated greater dlPFC and caudate activation, respectively, for real allergen itch. Subjects reporting greater nocebo-induced itch also demonstrated greater placebo reduction of allergen-evoked itch, suggesting increased generalized modulation of itch perception.

CONCLUSIONS

Our study demonstrates the capacity of nocebo saline to mimic both the sensory and neural effects of real allergens and provides an insight to the brain mechanisms supporting nocebo-induced itch in AD, thus aiding our understanding of the role that expectations and other psychological factors play in modulating itch perception in chronic itch patients.

Authors+Show Affiliations

Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. Department of Radiology, Logan University, Chesterfield, MO, USA.Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.Department of Dermatology and Allergy, Technische Universität München, Munich, Germany.Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.Program in Placebo Studies, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. Department of Dermatology and Allergy, Technische Universität München, Munich, Germany. Department of Prevention and Sports Medicine, Technische Universität München, Munich, Germany.

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

26280659

Citation

Napadow, V, et al. "The Imagined Itch: Brain Circuitry Supporting Nocebo-induced Itch in Atopic Dermatitis Patients." Allergy, vol. 70, no. 11, 2015, pp. 1485-92.
Napadow V, Li A, Loggia ML, et al. The imagined itch: brain circuitry supporting nocebo-induced itch in atopic dermatitis patients. Allergy. 2015;70(11):1485-92.
Napadow, V., Li, A., Loggia, M. L., Kim, J., Mawla, I., Desbordes, G., Schalock, P. C., Lerner, E. A., Tran, T. N., Ring, J., Rosen, B. R., Kaptchuk, T. J., & Pfab, F. (2015). The imagined itch: brain circuitry supporting nocebo-induced itch in atopic dermatitis patients. Allergy, 70(11), 1485-92. https://doi.org/10.1111/all.12727
Napadow V, et al. The Imagined Itch: Brain Circuitry Supporting Nocebo-induced Itch in Atopic Dermatitis Patients. Allergy. 2015;70(11):1485-92. PubMed PMID: 26280659.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The imagined itch: brain circuitry supporting nocebo-induced itch in atopic dermatitis patients. AU - Napadow,V, AU - Li,A, AU - Loggia,M L, AU - Kim,J, AU - Mawla,I, AU - Desbordes,G, AU - Schalock,P C, AU - Lerner,E A, AU - Tran,T N, AU - Ring,J, AU - Rosen,B R, AU - Kaptchuk,T J, AU - Pfab,F, Y1 - 2015/09/10/ PY - 2015/08/10/accepted PY - 2015/8/18/entrez PY - 2015/8/19/pubmed PY - 2016/8/4/medline KW - atopic dermatitis KW - caudate KW - nocebo KW - placebo KW - pruritus SP - 1485 EP - 92 JF - Allergy JO - Allergy VL - 70 IS - 11 N2 - BACKGROUND: Psychological factors are known to significantly modulate itch in patients suffering from chronic itch. Itch is also highly susceptible to both placebo and nocebo (negative placebo) effects. Brain activity likely supports nocebo-induced itch, but is currently unknown. METHODS: We collected functional MRI (fMRI) data from atopic dermatitis (AD) patients, in a within-subject design, and contrast brain response to nocebo saline understood to be allergen vs open-label saline control. Exploratory analyses compared results to real allergen itch response and placebo responsiveness, evaluated in the same patients. RESULTS: Nocebo saline produced greater itch than open saline control (P < 0.01). Compared to open saline, nocebo saline demonstrated greater fMRI response in caudate, dorsolateral prefrontal cortex (dlPFC), and intraparietal sulcus (iPS) - brain regions important for cognitive executive and motivational processing. Exploratory analyses found that subjects with greater dlPFC and caudate activation to nocebo-induced itch also demonstrated greater dlPFC and caudate activation, respectively, for real allergen itch. Subjects reporting greater nocebo-induced itch also demonstrated greater placebo reduction of allergen-evoked itch, suggesting increased generalized modulation of itch perception. CONCLUSIONS: Our study demonstrates the capacity of nocebo saline to mimic both the sensory and neural effects of real allergens and provides an insight to the brain mechanisms supporting nocebo-induced itch in AD, thus aiding our understanding of the role that expectations and other psychological factors play in modulating itch perception in chronic itch patients. SN - 1398-9995 UR - https://www.unboundmedicine.com/medline/citation/26280659/The_imagined_itch:_brain_circuitry_supporting_nocebo_induced_itch_in_atopic_dermatitis_patients_ L2 - https://doi.org/10.1111/all.12727 DB - PRIME DP - Unbound Medicine ER -