Severe itching, or pruritus, is a frequent and distressing symptom affecting older adults. It causes an urge to scratch and can range from mild irritation to a persistent problem. Pruritus is common in the elderly, with many individuals experiencing it.
When itching becomes chronic, lasting over six weeks, it can diminish quality of life. The discomfort interferes with daily activities, disrupts sleep, and contributes to anxiety or depression. Understanding its causes is important for managing this condition.
Skin-Specific Factors
Itching originating from the skin is common in older adults. A primary contributor is xerosis, or dry skin. As people age, reduced activity of sebaceous and sweat glands leads to less natural lubrication. This compromises the skin barrier, making it less effective at retaining moisture and more susceptible to dryness.
The skin’s pH also becomes more alkaline with age, disrupting the barrier and activating enzymes that contribute to itching. Dryness often appears as cracked, flaky, or scaly skin, especially on the legs and trunk. Xerosis discomfort often leads to scratching, which further damages the skin barrier and creates a persistent itch-scratch cycle.
Eczema, or dermatitis, frequently affects older adults, causing inflammation, redness, and itching. Asteatotic eczema is prevalent in geriatric populations, characterized by extremely dry, cracked skin resembling a “crazy paving” pattern, often on the shins. Contact dermatitis can also occur, as aging skin’s reduced barrier function and altered immune responses make it sensitive to irritants like chemicals or fabrics.
Psoriasis, a chronic inflammatory skin condition, can also cause widespread itching in the elderly. It presents as thick, red, scaly patches that can be intensely itchy, burning, or sore. The itching in psoriasis can be generalized across the body.
Bullous pemphigoid, an autoimmune blistering disease, is more frequent in individuals over 60. Intense itching can be the sole symptom for weeks or months before characteristic large, fluid-filled blisters appear. These blisters, common on skin folds, are accompanied by severe itching.
Underlying Health Conditions
Systemic diseases can cause itching in older adults, often without primary skin lesions. Kidney disease, especially chronic renal failure, commonly causes uremic pruritus. This itching is thought to involve toxin accumulation and immune system dysregulation. It can affect various body parts and often worsens at night.
Liver diseases that impair bile flow, known as cholestasis, also cause widespread itching. When bile cannot drain properly, bile salts and other substances accumulate in the bloodstream. These compounds are believed to irritate nerve endings in the skin, leading to intense itching that can be generalized.
Thyroid disorders, both hypothyroidism and hyperthyroidism, can trigger itching. Hypothyroidism can reduce perspiration, causing dry, flaky skin. Hyperthyroidism can increase blood flow and sweating, leading to irritation and itchiness.
Diabetes mellitus, especially with poorly controlled blood sugar, frequently contributes to pruritus. Mechanisms include increased skin dryness and diabetic peripheral neuropathy, which affects nerve function. This nerve involvement can lead to itching, burning, or tingling sensations. Scratching due to diabetes-related itching can create skin wounds, increasing infection risk.
Certain blood disorders can also cause generalized itching. Iron deficiency anemia has been linked to pruritus, possibly due to changes in skin barrier function. Polycythemia vera, a disorder involving red blood cell overproduction, commonly causes itching, often triggered by water contact. This “aquagenic pruritus” may arise from histamine release.
Cancers, including lymphomas like Hodgkin’s lymphoma, can cause itching, sometimes before other symptoms appear. This cancer-related itching is believed to result from the release of chemicals like cytokines by tumor or immune cells. These substances can irritate nerve endings, leading to generalized or localized pruritus.
Medications and Allergic Reactions
Medications commonly prescribed to older adults can cause itching as a side effect. This drug-induced pruritus can arise from direct pharmacological actions or immune reactions. Opioids, used for pain management, are known to cause itching, likely by triggering histamine release or affecting the central nervous system.
Certain blood pressure medications, such as ACE inhibitors, can induce itching by increasing bradykinin, a substance that causes swelling and irritation. Diuretics and statins, frequently used in the elderly, have also been linked to pruritus, sometimes contributing to dry skin or affecting skin barrier function. Some antibiotics and antidepressants can also lead to itchiness.
Allergic reactions to various substances can also cause itching in older individuals. Aging skin, being thinner and drier, may react more readily to contact allergens. Common culprits include metals like nickel, fragrances in personal care products, preservatives in cosmetics, and ingredients in topical medications. These contact reactions can result in itchy, red, and swollen skin, manifesting as allergic contact dermatitis.
Allergic responses can also occur from ingested substances. In the elderly, drug allergies more frequently cause widespread itching than food allergies. Such reactions can range from mild skin irritation to severe conditions like acute urticaria (hives) and angioedema, which involve swelling. Identifying and avoiding the specific medication or allergen is key to alleviating this type of itching.
Neurological and Infectious Causes
Itching can also stem from the nervous system or from infections and infestations. Neuropathic pruritus arises from damage or dysfunction of nerve pathways, either peripheral or central, rather than a primary skin condition. Post-herpetic neuralgia is a notable example, where persistent itching can occur in the area previously affected by shingles, due to nerve damage from the varicella-zoster virus.
Stroke-related itching, though less common, is another neuropathic pruritus that can occur after a cerebrovascular accident. This central itch results from lesions in brain regions involved in processing sensations. Such itching can be localized or affect one side of the body, presenting without obvious skin changes. Other nerve issues, including nerve compression or diabetic polyneuropathy, can also lead to chronic itching.
Severe itching may have a psychogenic origin, influenced by psychological factors. Stress, anxiety, and depression can exacerbate or initiate itching. This type of pruritus commonly affects easily accessible areas like the arms and upper trunk.
Infectious agents and parasites are also causes of itching, particularly in the elderly. Scabies, caused by tiny mites that burrow into the skin, leads to itching often worse at night. This contagious infestation can spread rapidly in close-contact environments like nursing homes. Severe cases, known as crusted scabies, involve widespread skin thickening with a high mite burden.
Fungal infections, such as athlete’s foot (tinea pedis) or yeast infections (candidiasis) in skin folds, are common in older adults and cause itchy, red, scaly rashes. These infections thrive in warm, moist conditions and can be persistent. Bacterial skin infections can also contribute to itching, often as a secondary complication when scratching compromises the skin barrier, allowing bacteria like Staphylococcus aureus to cause conditions like impetigo or cellulitis.