The Relationship Between Dermatologic Diseases and Dementia; A Review

In some inflammatory skin diseases such as bullous pemphigoid, psoriasis and atopic dermatitis, inflammation is not limited to the skin but spreads systemically. Systemic inflammatory processes can activate proinflammatory cytokines, stimulate neurons and microglia in the brain, and trigger neuroinflammation. Ultimately, some skin diseases may affect the course of dementia and worsen the prognosis. Dementia, which progresses with a decrease in cognitive functions, can also trigger some skin diseases, accelerate their formation, and increase their severity. For example; bullous pemphigoid and dementia are two complex disease groups with multifaceted interactions. The strongest association among bullous pemphigoid comorbidities is with neurological diseases. The effect on cognitive impairment in patients with atopic dermatitis begins in infancy. The risk of cognitive impairment increases in the first year, especially in herpes zoster patients with trigeminal nerve involvement. In delusional parasitosis, which is a delusional disorder, patients first apply to dermatologists, and delusional parasitosis accompanies Lewy body dementia, one of the dementia types. This review aims to summarize dermatological diseases associated with dementia, such as bullous pemphigoid, psoriasis, atopic dermatitis, herpes zoster, crusted scabies, and delusional parasitosis, and to provide suggestions based on these relationships that may provide dermatologists, neurologists, and psychiatrists with a new perspective on the management of dermatological findings in patients with dementia.