Publish date: Posted on
Last updated: October 21, 2023
Keywords #
functional pruritus
somatoform pruritus
functional itch disorder
Diagnosis #
Pruritus is a commonly reported symptom in psychiatric patients and can be a side effect of many psychiatric medications. Conversely, psychiatric co-morbidities, including anxiety and depression, are commonly seen in patients suffering from chronic pruritus.[1] Psychogenic pruritus should be a diagnosis of exclusion after a comprehensive work-up for pruritus without rash. It is related to psychologic factors that can elicit, worsen, and sustain the symptoms. Psychogenic pruritus may require cooperation between dermatologists and psychiatrists to properly manage the disease.
Key Concepts #
- Pruritus without primary skin findings is most common. Secondary skin findings, such as excoriations and hemorrhagic crusts, are very common.
- Psychological factors play an evident role in the triggering, intensity, aggravation, or persistence of the pruritus.
- Psychogenic itch may accompany other psychiatric conditions like depression, anxiety, obsessive-compulsive disorders, psychoses, and substance use.[1]
Epidemiology #
In a series of 100 psychiatric inpatients, the prevalence of generalized pruritus was 42%.[2] A subsequent epidemiological study of psychogenic itch reported that 6.5% of outpatients from a university dermatology department suffered from “somatoform pruritus.”[3]
Clinical Features #
- Chronic pruritus (greater than six weeks) without an underlying primary skin lesion.
- On physical examination, scattered, linear, crusted lesions may be present anywhere on the body within reach of the patient, although they are most often confined to the extremities.[4]
- The “butterfly sign” is a pattern of skin-sparing seen on the mid-back where the patient cannot reach to scratch.
Differential Diagnoses #
- Small fiber neuropathy
- Functional mucocutaneous disorder
- Delusional infestation
- Substance use disorder
- Psychogenic urticaria
- Compulsive skin picking
Diagnostic Workup #
No diagnostic workup is indicated for psychogenic pruritus as it is considered a clinical diagnosis of exclusion.
Treatment #
Due to the complex, multifaceted mechanism surrounding pruritus, combination treatments are often necessary. Treatments largely center around influencing the central nervous system and include selective serotonin reuptake inhibitors, H1-antihistamines, tricyclic antidepressants, antipsychotic drugs, and anticonvulsants like topiramate.[5]Occlusive dressings and steroid injections are helpful adjuncts for resistant lesions. In addition, psychotherapy is strongly recommended in the long-term management of these patients.
Slide Viewer #
https://utahderm.med.utah.edu/image-viewer/References #
- Lee HG, Stull C, Yosipovitch G. Psychiatric disorders andpruritus. Clin Dermatol. 2017 May-Jun;35(3):273-280. doi: 10.1016/j.clindermatol.2017.01.008. Epub 2017 Jan 22. PMID: 28511824.3.
- Kretzmer GE, GelkopfM, Kretzmer G, Melamed Y. Idiopathic pruritus in psychiatric inpatients: an explorative study. Gen Hosp Psychiatry. 2008 Jul-Aug;30(4):344-8. doi: 10.1016/j.genhosppsych.2008.03.006. PMID: 18585538.
- Weisshaar E, Szepietowski JC, Darsow U, Misery L, Wallengren J, Mettang T, Gieler U, Lotti T, Lambert J, Maisel P, Streit M, Greaves MW, Carmichael AJ, Tschachler E, Ring J, Ständer SActa Derm Venereol. 2012 Sep; 92(5):563-81.
- Greco PJ, Ende J. Pruritus: a practical approach. J Gen Intern Med. 1992 May-Jun;7(3):340-9. doi: 10.1007/BF02598094. PMID: 1351941.
- Psychiatric medications for the treatment of pruritus.Shaw RJ, Dayal S, Good J, Bruckner AL, Joshi SVPsychosom Med. 2007 Dec; 69(9):970-8.
