Based on NIH | Is skin rash a symptom of Alzheimer’s disease, and what other causes should be considered in patients with Alzheimer’s who develop a rash?

Skin rash is not considered a typical or core symptom of Alzheimer’s disease itself. Alzheimer’s primarily affects memory, thinking, behavior, and daily functioning; common features include progressive memory loss, disorientation, language difficulties, and behavior or personality changes, not skin changes. ^{[1] [2]} As the disease progresses, individuals may require total care, but rashes are not listed among hallmark manifestations of the condition. ^{[1] [3]}

Why rashes still appear in people with Alzheimer’s

• Aging skin and itch-prone conditions: Older adults often have dry skin, impaired skin barrier repair, and immune changes that make itchy rashes more common (for example, eczema-like eruptions, xerosis, and other pruritic dermatoses). ^[4] These age-related factors may overlap with neurodegenerative disease and contribute to pruritus in the elderly. ^[4]
• Coexisting medical skin diseases: Many common rashes in the general population also affect people with Alzheimer’s, including contact dermatitis (irritant or allergic), eczema (atopic dermatitis), psoriasis, seborrheic dermatitis, and infections (fungal, bacterial, viral). ^{[5] [6]} Some rashes can be triggered by allergens or irritants the skin touches (like soaps, fragrances, plants, adhesives). ^{[7] [5]}

Frequently overlooked causes in Alzheimer’s care

• Medication-related rashes: Drug eruptions are common in older adults and range from mild maculopapular rashes and hives to rare, serious reactions such as DRESS (drug reaction with eosinophilia and systemic symptoms). ^{[8] [9]} In dementia care, certain medicines are known to cause skin reactions:
  • Donepezil (oral) lists rash, itching (pruritus), hives (urticaria), and vesiculobullous eruptions among reported skin side effects. ^{[10] [11]}
  • Donepezil patches (transdermal systems) can cause application-site irritation such as redness (erythema), papules, and mild edema. ^{[12] [13]}
  • Rivastigmine patches commonly cause irritant contact dermatitis and may rarely cause allergic contact dermatitis, which can extend beyond the patch borders and include vesicles/edema. ^[14] Patch misuse (not rotating sites, applying too long) increases risk. ^[14] Atypical sensitization to rivastigmine patches has also been reported. ^[15]
  • Anticonvulsants used for behavioral symptoms (e.g., carbamazepine) can rarely cause severe reactions like DRESS that require urgent drug cessation. ^[16]
    Because polypharmacy is common in older adults, reviewing all medications (including new starts in the prior 2–8 weeks) is essential when a rash appears. ^{[8] [9]}
• Pressure injuries (bedsores) and moisture-related dermatitis: Limited mobility, incontinence, fragile skin, and cognitive impairment increase the risk of pressure ulcers over bony areas (heels, sacrum, hips, shoulder blades) and dermatitis in skin folds. ^{[17] [18]} Pressure ulcers arise from prolonged pressure that reduces blood flow; prevention includes frequent repositioning, pressure-relieving surfaces, and good skin care. ^{[17] [18]}
• Infections in dependent skin areas: Bacterial impetigo/cellulitis, fungal intertrigo (yeast in skin folds), and viral rashes (like shingles) may occur and can be more difficult to recognize in individuals with cognitive impairment. ^{[19] [20]}

How to differentiate common possibilities

• Contact dermatitis (irritant or allergic): Red, itchy, eczematous patches; irritant reactions stay within contact borders (e.g., a patch outline), while allergic reactions may spread beyond with swelling or vesicles. ^{[14] [5]}
• Drug eruption: Often a widespread, symmetric red maculopapular rash appearing days to weeks after starting a new medication; may include itching; severe cases can include fever, facial edema, mucosal involvement, organ dysfunction (seek urgent care). ^[8]
• Seborrheic dermatitis: Redness and greasy scale on scalp (dandruff), eyebrows, nasolabial folds, ears, chest; often chronic and recurrent. ^[6]
• Eczema (atopic dermatitis)/xerosis: Dry, itchy, scaly patches; worse with soaps, hot water, and low humidity. ^[19]
• Psoriasis: Well-defined red plaques with silvery scale, often on elbows, knees, scalp; may itch. ^[19]
• Pressure injury/moisture-associated skin damage: Redness or skin breakdown over bony prominences or in areas exposed to moisture from incontinence; look for staged ulcers or maceration. ^{[17] [18]}
• Infections:
  • Fungal: red, moist plaques in skin folds with satellite pustules (intertrigo). ^[20]
  • Bacterial (impetigo/cellulitis): honey-colored crusts or tender, warm redness with swelling; may require antibiotics. ^[19]
  • Viral (shingles): painful, grouped blisters in a band-like pattern on one side of the body. ^[19]

Practical next steps if a person with Alzheimer’s develops a rash

1. Review recent changes: List all new medications (including patches), over-the-counter products, supplements, and skin products started within the past 2–8 weeks. Many drug eruptions begin in this window. ^[8]
2. Check patch technique if used: Ensure proper rotation of application sites, avoid damaged or recently shaved skin, limit wear time as directed, and carefully remove patches; use emollients for irritant reactions and consider topical corticosteroids for allergic reactions under clinician guidance. ^{[14] [12]}
3. Assess severity: Seek urgent care for red flags such as fever, widespread blistering, mucosal lesions (mouth/eyes/genitals), facial swelling, swollen lymph nodes, or signs of organ involvement these can signal severe drug reactions. ^{[8] [16]}
4. Skin care basics: Gentle, fragrance-free cleansers; lukewarm bathing; liberal use of bland emollients to repair the barrier; avoid known irritants/allergens when possible. ^[5]
5. Prevent pressure-related damage: Reposition at least every 2 hours in bed, use cushions or specialty mattresses, keep skin clean and dry, and maintain good nutrition/hydration to reduce risk of bedsores. ^{[18] [17]}
6. Get a focused exam: A clinician may perform skin scraping, culture, or biopsy if the cause is unclear or if infection is suspected. ^[5]
7. Medication management: If a medication-related rash is suspected, do not stop prescribed drugs abruptly without advice unless severe symptoms are present; prompt medical review is important to weigh risks and benefits and to substitute safer alternatives when needed. ^[8]

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Key takeaways

• Rash is not a typical symptom of Alzheimer’s disease; cognitive and behavioral changes define the condition. ^{[1] [2]}
• In individuals with Alzheimer’s, rashes usually come from common dermatologic conditions, medication reactions (including cholinesterase inhibitors and patches), infections, or pressure/moisture-related skin injury. ^{[14] [12]}
• Older age increases the likelihood of itchy inflammatory skin diseases and drug eruptions, so a structured evaluation and prevention plan can make a meaningful difference. ^{[4] [9]}

If you’d like help narrowing down the likely cause, sharing where the rash is located, what it looks like (color, scale, blisters), when it started relative to any new medications or patches, and any associated symptoms (fever, pain, swelling) can guide next steps.