DermHelpCentral

Chronic Itching in the Elderly

1. Itch Management in the Elderly: Download Itch Management in the Elderly

Leslie TA1. Curr Probl Dermatol. 2016, 50, 192–201 

Abstract

Itch is a common symptom in the elderly population over 65 years old, and is often a chronic condition lasting more than 6 weeks. As in all age groups, but especially in the elderly, there can be a significant effect on the general health status and quality of life, with impaired daily activities and lack of sleep, which can also lead in some cases to depression or anxiety. The cause of chronic itch in the elderly is often multifactorial due to physiological changes in the aging skin, including impaired skin barrier function, and also due to decline in immunological (immunosenescence), neurological, and psychological changes associated with age. Common causes of chronic pruritus in the aging skin include xerosis (dry skin), dermatological disorders (eczema, psoriasis, lichen planus), and systemic (renal, hepatic, endocrine), neurodegenerative, and psychological diseases. Comorbidities in the elderly population lead to polypharmacy, increasing the potential risk of drug side effects, which can result in causing or exacerbating itch in the elderly patient. It is essential to obtain a detailed history, including drugs, as well as a thorough clinical examination with appropriate subsequent investigations. Management of the elderly patient with chronic pruritus should include treatment with topical therapies such as emollients as well as other agents for symptomatic relief. Systemic therapies should be directed at any underlying cutaneous or systemic diseases. Often the cause of itch in the elderly cannot be found and some systemic treatments can be used for symptomatic control of the itch, including antihistamines, gabapentin, and selective antidepressants. A holistic approach needs to be taken on an individual basis to relieve chronic pruritus, as the management of itch in the elderly can be a challenge.

 

2. Causes, pathophysiology, and treatment of pruritus in the mature patient.

Shevchenko A1, Valdes-Rodriguez R1, Yosipovitch G2. Clin Dermatol. 2018 Mar - Apr;36(2):140-151

Abstract: Download Causes of Pruritus in Elderly

Chronic itch is a common and debilitating health condition in the elderly. There are several common causes of itch in the mature population, such as skin xerosis, immunosenescence, and neuropathic changes. In addition, skin diseases, such as seborrheic dermatitis and stasis dermatitis, systemic conditions (end-stage renal disease and diabetes), or psychogenic derailments, such as depression, anxiety, and dementia, can all serve as triggers of pruritus. Polypharmacy, a common occurrence among the elderly population, may also serve as a cause of itch that may or may not be accompanied by dermatitis. Such medications as μ opioids and calcium channel blockers have been found to have a connection with pruritus in the advanced aging population. Determining the exact trigger for pruritus in the elderly may be especially challenging, because itch can be idiopathic in many cases. The role of treatments should not only take into account elimination of various underlying cutaneous, systemic, or psychogenic conditions associated with itch but also focus on the skin changes that are characteristic of the aging process. Development of such treatment options can be guided by elucidation of the mechanisms underlying the pathophysiology of itch in the geriatric population.

The Itch (Fiction)

by Don Delilo

The New Yorker, August 4, 2017

This is a somewhat existential story about a New York businessman with a persistent and very annoying itch. As a piece of fiction, it works.  Its insights into patients and dermatologists are amusing and instructive.  If this URL does not work, it should be relatively easy to find a copy of this New Yorker.

Excerpts:
He was in the examining room describing his situation to the dermatologist as he lay flat on his back wearing a knee-length garment, open-fronted, over his boxer shorts. She was checking his ankles, shins, and thighs. She spoke absently about the pathology of the skin.

 The dermatologist recited the names of soap and shampoo brands, described conditions that might arise from symptoms such as his, and he tried to memorize all this, which was difficult to manage in his state of partial undress. Do we need to be fully dressed, he thought, for our memory to function properly?

 The new doctor’s name, online, in tribute, was the Itch Meister. He was short and broad with the look of a man who lives with one central obsession. The Itch Meister instilled confidence with a few short sentences, although he didn’t seem to address the patient’s remarks directly and unequivocally.

 When the visit was ending, the patient put on his pants, shirt, and shoes, and the doctor wrote a couple of prescriptions.

 “When you pick up the medications, you will be reading the instructions printed on the inserts but you will not follow them. They are stupid and misleading. Do not use the medications two, three, four times a day. You are hearing me say this. Once a day.”

 They had a corner table in a nearly empty café. His plan was to avoid details and simply say that the itch was a livable condition but not likely to be alleviated anytime soon.

The Neurology of Itch

The neurology of itch.
Dhand A1, Aminoff MJ. Brain. 2014 Feb;137(Pt 2):313-22
Abstract: Research over the past 15 years has helped to clarify the anatomy and physiology of itch, the clinical features of neuropathic itch syndromes and the scientific underpinning of effective treatments. Two itch-sensitive pathways exist: a histamine-stimulated pathway that uses mechanically insensitive C-fibres, and a cowhage-stimulated pathway primarily involving polymodal C-fibres. Interactions with pain continue to be central to explaining various aspects of itch. Certain spinal interneurons (Bhlhb5) inhibit itch pathways within the dorsal horn; they may represent mediators between noxious and pruritic pathways, and allow scratch to inhibit itch. In the brain, functional imaging studies reveal diffuse activation maps for itch that overlap, but not identically, with pain maps. Neuropathic itch syndromes are chronic itch states due to dysfunction of peripheral or central nervous system structures. The most recognized are postherpetic itch, brachioradial pruritus, trigeminal trophic syndrome, and ischaemic stroke-related itch. These disorders affect a patient's quality of life to a similar extent as neuropathic pain. Treatment of neuropathic itch focuses on behavioural interventions (e.g., skin protection) followed by stepwise trials of topical agents (e.g., capsaicin), antiepileptic drugs (e.g., gabapentin), injection of other agents (e.g., botulinum A toxin), and neurostimulation techniques (e.g., cutaneous field stimulation). The involved mechanisms of action include desensitization of nerve fibres (in the case of capsaicin) and postsynaptic blockade of calcium channels (for gabapentin). In the future, particular histamine receptors, protease pathway molecules, and vanilloids may serve as targets for novel antipruritic agents. Free Full Text.

Prurigo, Pets, Vets

Cheyletiella Mite

Some patients with unexplained itchy bumps may be infested with miters from dogs or cats.  One of the best articles on the subject appeared in the British Medical Journal in 1979.  The  Cheyletiella mite can infest dogs, cats, rabbits and other mammals.

Prurigo and pets: the benefit from vets.
M Kieffer, S Kristensen, and T E Hallas
Br Med J. 1979 June 9; 1(6177): 1539–1540.

Itching and PBC

Primary biliary cirrhosis (PBC) is a liver disease of unknown etiology characterized by the presence of anti-mitochondrial antibodies in serum, chronic non-suppurative cholangitis on liver histology and cholestasis Itch is the most common symptom associated with PBC. It has been reported to occur in 25–70% of patients with PBC.  Here is a good article on itch in PBC:   Download Itch PBC  

What worked the best for these patients was antihistamines, cholestyramine and prednisone.  The latter may be associated with unacceptable side-effects with long-term use.