skin aging (includes aging of skin appendages)
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Introduction
Also see dermatoheliosis.
Pathology
Age-related changes in skin:
- increased wrinkling
- atrophy of sweat glands & sebaceous glands
- decreased number & growth of hairs
- xerosis
- changes in epidermis
- epidermis thins with age
- stratum corneum looses basket-weave pattern
- becomes thin & compact & less effective barrier
- diminished epidermal turnover
- reduced mitotic rate of epidermal basal cells
- increased time of epidermal wound healing
- decreased number & function of melanocytes
- skin pallor
- diminished number of Langerhans cells (40-50%)
- decreased delayed hypersensitivity
- decreased surface area of basement membrane
- shortened & attenuated rete ridges
- decreased production of vitamin D
- decreased sebum production
- changes in dermis
- dermis thins with age 20%
- loss of papillary dermis leading to a decrease in volume & loss of rete ridges
- diminished number of fibroblasts*
- decreased proteoglycans, collagen, elastin
- decreased strength & elasticity of skin
- diminished production of type 1 procollagen by fibroblasts occurs with chronological aging of human skin via downregulation of the TGF-beta/Smad/CTGF axis[6]
- decrease in elastin fibers[10]
- increase in collagen cross-links
- it has been proposed that skin aging is caused by the loss of papillary fibroblasts, which affects
- skin elasticity (decreased skin elasticity)
- matrix production & degradation
- epidermal interaction
- basement membrane homeostasis[7]
- decreased proteoglycans, collagen, elastin
- diminished number of blood vessels & capillaries
- impaired thermoregulation, response to injury
- loss of hydration
- loss of elasticity[5]
- diminished number of mast cells
- decreased immediate hypersensitivty
- diminished nerve endings (30%)
- decreased sensation, increased pain threshold
- decreased subcutaneous fat
- decreased skin temperature[5]
- cyclo-oxygenase 2 (COX2) may play a role[11]
- barrier function of aged skin is less effective than younger skin[15]
- delayed wound healing
Age-related changes in skin appendages:[3]
- hair loss
- androgen-dependent (male-balding)
- involutional alopecia
- begins after age 40
- decrease in hair shaft diameter
- decrease in number of hairs
- loss of hair follicles
- graying of hair
- loss of functional melanocytes in hair bulb
- by age 50, 1/2 of all body hairs become gray
- eyebrow, ear & nasal hair coarsen & get longer, especially in men
- nail plate thickness & growth rate decrease with age
- nails become more brittle
- sebaceous glands hypertrophy with age
- sebum production diminishes with age
- apocrine & eccrine glands decrease in density & accumulate lipofuscin
Age-related skin lesions
- seborrheic keratosis
- cherry anigiomas
- nevi may involute or disappear by the 6th or 7th decade of life
The number of senescent fibroblasts* increases exponentially in the skin of aging baboons, reaching > 15% of all cells invery old individuals.[1]
* determined by:
- shortened telomeres
- activated ataxia-telangiectasia mutated kinase
- heterochromatinized nuclei
Clinical manifestations
- aged skin is thin & inelastic, tearing easily[15]
- aged skinrecovers more slowly from mechanical depression than younger skin
- women have thinner skin then men
- aged skin is dry, especially after frequent washing with
- pigmentation is uneven due to melanocyte activation (melanosis) & inactivation (guttate hypomelanosis)
- in genetically predisposed elderly:
- telangiectases & cherry angiomas
- seborrhoeic keratoses
* images[15]
Complications
- increased risk of Herpes zoster
- chronic onychomycosis & Tinea pedis
- asteatotic eczema
- also see dermatologic disorders in the elderly
Differential diagnosis
- dermatoheliosis
- coarse epidermal folds
- diffuse pigmentation or 'bronzing'
- solar lentigo
- elastosis
- solar purpura
- telangiectasias
Management
- regular use of emollients[5]
- sunscreen, protective clothing
- topical retinol (0.4%) 3 times/week improves temporarily clinical signs of naturally aged skin[4]
- alpha-hydroxy acids & beta-hydroxy acids may have some benefit[5]
More general terms
Additional terms
References
- ↑ 1.0 1.1 Herbig U, Ferreira M, Condel L, Carey D, Sedivy JM. Cellular senescence in aging primates. Science. 2006 Mar 3;311(5765):1257. Epub 2006 Feb 2. PMID: https://www.ncbi.nlm.nih.gov/pubmed/16456035
- ↑ Gilchrest BA, Aging of the Skin, In: Principles of Geriatric Medicine, 4th ed,, Hazzard et al (eds), McGraw-Hill, NY, 1999, pg 573-602
- ↑ 3.0 3.1 Freeman AK and Gordon M, Dermatologic diseases and problems, In: Geriatric Medicine: An Evidence-Based Approach, 4th ed, Cassel CK et al (eds), Springer-Verlag, New York, 2003
- ↑ 4.0 4.1 Kafi R et al, Improvement of naturally-aged skin with vitamin A (retinol) Arch Dermatolo 2007, 143:606 PMID: https://www.ncbi.nlm.nih.gov/pubmed/17515510
- ↑ 5.0 5.1 5.2 5.3 5.4 Medical Knowledge Self Assessment Program (MKSAP) 15, 16, 17, 18. American College of Physicians, Philadelphia 2009, 2012, 2015, 2018.
- ↑ 6.0 6.1 Quan T et al. Reduced expression of connective tissue growth factor (CTGF/CCN2) mediates collagen loss in chronologically aged human skin. J Invest Dermatol 2010 Feb; 130:415. PMID: https://www.ncbi.nlm.nih.gov/pubmed/19641518
- ↑ 7.0 7.1 Janson DG et al. Different gene expression patterns in human papillary and reticular fibroblasts. J Invest Dermatol 2012 Nov; 132:2565 PMID: https://www.ncbi.nlm.nih.gov/pubmed/22696053
- ↑ Uitto J. The role of elastin and collagen in cutaneous aging: intrinsic aging versus photoexposure. J Drugs Dermatol. 2008 Feb;7(2 Suppl):s12-6. PMID: https://www.ncbi.nlm.nih.gov/pubmed/18404866
- ↑ Yaar M, Gilchrest BA. Skin aging: postulated mechanisms and consequent changes in structure and function. Clin Geriatr Med. 2001 Nov;17(4):617-30, v. PMID: https://www.ncbi.nlm.nih.gov/pubmed/11535419
- ↑ 10.0 10.1 Geriatric Review Syllabus, 8th edition (GRS8) Durso SC and Sullivan GN (eds) American Geriatrics Society, 2013
- ↑ 11.0 11.1 Habib MA et al. Comparative immunohistochemical assessment of cutaneous cyclooxygenase-2 enzyme expression in chronological aging and photoaging. Photodermatol Photoimmunol Photomed 2014 Feb; 30:43 PMID: https://www.ncbi.nlm.nih.gov/pubmed/24393208
- ↑ Beer KR Combined treatment for skin rejuvenation and soft-tissue augmentation of the aging face. J Drugs Dermatol. 2011 Feb;10(2):125-32. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/21283916
- ↑ Farage MA, Miller KW, Elsner P, Maibach HI. Characteristics of the Aging Skin. Adv Wound Care (New Rochelle). 2013 Feb;2(1):5-10. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/24527317
- ↑ Farage MA, Miller KW, Berardesca E, Maibach HI. Clinical implications of aging skin: cutaneous disorders in the elderly. Am J Clin Dermatol. 2009;10(2):73-86. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/19222248
- ↑ 15.0 15.1 15.2 15.3 DermNet NZ. Ageing skin (images) http://www.dermnetnz.org/site-age-specific/ageing.html
- ↑ Blume-Peytavi U, Kottner J, Sterry W et al Age-Associated Skin Conditions and Diseases: Current Perspectives and Future Options. Gerontologist. 2016 Apr;56 Suppl 2:S230-42. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/26994263