The International Forum for the Study of Itch defines itching, medically known as “pruritus”, as the unpleasant sensation that provokes an urge to scratch. Conditions specific to the skin, underlying systemic issues, or a combination of both can cause itching. Pruritus is a relatively common and frequently frustrating symptom encountered in end-of-life care.
Dermatologic conditions, such as dryness, wetness, or irritation from eczema, psoriasis, or local irritants, most frequently cause localized pruritus. Skin naturally dries as we age, and hydration of the skin is the primary treatment with emollients and moisturizers. Cooling agents, such as Calamine or Menthol, can be helpful with itching also. If local inflammation is present on the skin, topical steroid creams and ointments are a solution to treat the underlying skin condition in many cases.
Metabolic derangements can also be a cause of itching, including liver failure, kidney failure, and hypothyroidism. Liver failure or liver malignancies can produce cholestasis, a condition that impairs the flow of bile from the liver to the small intestine, causing increased bilirubin levels. This typically causes generalized pruritus that can be worse on the palms and soles. Kidney failure produces a build-up of uremia, and uremic pruritus is a common symptom in individuals with renal failure, particularly those on chronic dialysis treatment. This itching is typically generalized and can be continuous or intermittent. Uncontrolled hypothyroidism can also lead to generalized pruritus and overall skin dryness.
Hematologic disorders, including iron deficiency, leukemia, lymphoma, and polycythemia vera can cause itching that is often aquagenic, meaning exacerbated by contact with water. Other solid organ malignancies, such as breast cancer, anal cancer, and prostate cancer, can generate itching around the tumor site, often associated with an overlying rash. Infestations with scabies or lice and yeast infections can cause itching in the area affected. Treatment of the underlying infecting organism is the treatment of choice.
Patients and Pruritus
Patients with HIV infection and AIDS have a higher prevalence of pruritus. Underlying skin infections, reactions to treatment medications, or subsequent viral-induced neuropathy are all causes. The pruritus may be generalized or localized to the area of the skin issue.
A true allergic cause of pruritus can also be present. This can develop due to a medication allergy or contact dermatitis due to an underlying agent. However, some medications can cause itching, not in the setting of a true allergy. In other words, the medication makes you itch, but you are not allergic to it. In a hospice setting, opioid use is usually the culprit. Some antibiotics, aspirin, and anti-inflammatory agents can also produce the same reaction. With opioids, the pruritus is typically generalized and may even cause hives. Persistent opioid-induced pruritus only occurs in 1% of patients, but up to 10% of patients may have transient symptoms.
Psychogenic itching can also be present. A true cause for the itching cannot be determined, but the scratching can become dramatic. In a hospice setting, this is common for patients with dementia.
Regardless of the underlying cause, proper education on skin care strategies for all patients with itching is essential. These include hydration and lubrication of the skin, avoiding fragrances and irritants, and maintaining a cool external environment. Topical treatments are an option in the aforementioned situations. Systemic medications used to treat itching typically work quickly, when effective. Thus, if a prescribed anti-itch medication is not helping within a day, it is reasonable to attempt treatment with another class of medication.
Antihistamines, such as Benadryl or Zyrtec, are useful if the itching is due to a true allergic response. A class of anti-nausea medications, 5HT3 antagonists (ex. Zofran), can be helpful for patients with pruritus due to cholestasis, uremia, or opioid use. An older cholesterol-reducing medication, cholestyramine, can be helpful for cholestatic pruritus. Antidepressants, as a class, may be effective for pruritus due to multiple causes. Finally, two medications, typically used to treat neuropathic pain, gabapentin, and pregabalin, have also been found to be effective for multiple types of itching.
In summary, itching may be a common annoyance for many of us from time to time, but when the itching persists and becomes a hindrance to the quality of life, treatment is necessary. It is always best to treat the underlying cause of the pruritus if known. However, when that is not possible, due to end-stage disease, we must find ways to treat the symptom and minimize morbidity. At Hospice of Southern Illinois, our mission is to improve the quality of life for those touched by terminal illness. Sometimes that means something as simple as making the itch go away.
- Dalal MD S. Overview of pruritus in palliative care. Uptodate.com. May 10, 2021.
- Von Gunten C MD, Kammell MD A, Ferris MD, F. Fast Facts Pruritus. Palliative Care Network of Wisconsin. Aug 2020.