19 - 106 - SKIN AGING Flashcards
Which type of skin aging is characterized by xerosis, formation of wrinkles, decreased elasticity, fragility?
a. Extrinsic
b. Intrinsic
c. Both
d. None of the above
C
Which type of skin aging is characterized by changes such as decreased collagen production, reduced blood flow, lowered amounts of lipids, loss of rete ridges?
a. Extrinsic
b. Intrinsic
c. Both
d. None of the above
B
Which type of skin aging is characterized by typical features such as deep wrinkles, laxity, coarseness, increased fragility, multiple telangiectases, darker skin with mottled pigmentation?
a. Extrinsic
b. Intrinsic
c. Both
d. None of the above
A
Which condition/s is often associated with a history of habitual or intense intermittent sun exposure?
a. BCC
b. SCC
c. Melanoma
d. A and B
e. A and C
f. B and C
E
What is the most pronounced and consistent histologic change of aged skin?
A. Atypia and decrease in number of functional melanocytes
B. Increased number of melanocytes
C. Decreased number of Langerhans cells
D. Flattening of dermo epidermal junction and loss if rete ridges
D
includes the inevitable physiologic changes of the skin that occur with time and are influenced by genetic and hormonal factors
Intrinsic skin aging
preventable structural and functional changes of the skin that occur with exposure to environmental factors, the most important source being ultraviolet radiation
Extrinsic skin aging
alterations in intrinsic skin aging
- decreased collagen production,
- reduced blood flow,
- lowered amounts of lipids, and the
- loss of rete ridges
- result is dry, pale skin with fine wrinkles, less elasticity, and impaired reparative capacity
most powerful source of extrinsic aging
ultraviolet radiation
ultraviolet radiation–mediated structural and functional changes of the skin
photoaging
Other exogenous factors that contribute to extrinsic skin aging aside from UVR
- cigarette
smoking, - diet,
- chemical exposure,
- trauma, and
- air pollutants (eg, particulate matter, CO2 , CO, SO2 , NO, and NO_
Typical clinical features of extrinsically aged skin, which are mostly ultraviolet radiation–mediated
- deep wrinkles,
- laxity,
- coarseness,
- increased fragility, and
- multiple telangiectases
- Moreover, photodamaged skin may appear darker and have mottled pigmentation
- Extrinsically aged skin has an increased tendency to develop benign and malignant growths
Intrinsic or Extrinsic Skin aging?
Epidermal thinning
Intrinsic
Intrinsic or Extrinsic Skin aging?
Solar elastosis
Extrinsic
Intrinsic or Extrinsic Skin aging?
Loss of rete ridges
Intrinsic
Intrinsic or Extrinsic Skin aging?
Reduced number of fibroblasts
Extrinsic
Intrinsic or Extrinsic Skin aging?
Reduced amount of extracellular matrix
extrinsic
Intrinsic or Extrinsic Skin aging?
Decreased number of collagen and elastin fibers
intrinsic
Intrinsic or Extrinsic Skin aging?
Xerosis
BOTH
Intrinsic or Extrinsic Skin aging?
Pallor
Intrinsic
Intrinsic or Extrinsic Skin aging?
Multiple telangiectases
Extrinsic
Intrinsic or Extrinsic Skin aging?
Fine wrinkles
intrinsic
Intrinsic or Extrinsic Skin aging?
Deep wrinkles
extrinsic
Intrinsic or Extrinsic Skin aging?
decreased elasticity
BOTH
Intrinsic or Extrinsic Skin aging?
Fragility
both
Intrinsic or Extrinsic Skin aging?
dyspigmentation
extrinsic
only penetrates into the epidermis and upper dermis, is a chief source of direct DNA damage, inflammation, and immunosuppression
UVB
- Of the UV radiation that reaches the earth’s surface, more than 95% is UVA (320 to 400 nm) and approximately 5% is UVB (280 to 320 nm).
- Both UVA and UVB contribute to skin aging.
UVR that deeply penetrates the skin down to the lower dermis
UVA
UVR considered a larger contributor to skin aging
UVA
because of its greater depth of penetration and its higher percentage of surface sunlight.
Infrared spectrum that can reach down to the hypodermis, increase reactive oxygen species production, and impact mitochondrial integrity
infrared A
- Infrared B and infrared C do not penetrate the skin well
- Nearly 45% of the solar spectrum reaching human skin is infrared, which is composed of infrared A (700 to 1400 nm), infrared B (1400 to 3000 nm), and infrared C (3000 nm to 1 mm).
Impact of Estrogens on Skin Physiology
what layer of the epidermis appears to be the most greatly impacted by epidermal atrophy in skin aging?
spinous cell layer
what layers of the epidermis are largely unaffected by skin aging?
stratum corneum and stratum granulosum are largely unaffected
most pronounced and consistent histologic change of aged skin
flattening of the dermal–epidermal junction and loss of rete ridges, resulting in decreased surface contact area and presumably less nutritional support of the avascular epidermis by the vascularized dermis
These alterations account for the increased fragility of aged skin to minor trauma as well as propensity to blister
Although the density of melanocytes doubles in photodamaged skin, the number of functional melanocytes in the basal layer declines by up to how many percent per decade?
20% per decade
Acute UV irradiation transiently upregulates 3 MMPs the skin, with the epidermis being the major source
MMP-1, MMP-3, and MMP-9
- In contrast, chronically photodamaged skin has been shown to constitutively express higher levels of 7 MMPs (MMP-1, MMP-2, MMP-3, MMP-9, MMP-11, MMP-17, and MMP-27), which are primarily derived from dermal fibroblasts
- The resulting fragmentation of collagen is unable to produce an amount of mechanical tension on the fibroblasts to stimulate collagen synthesis.
- Thus, elevated MMP activity in the dermis of photodamaged skin creates a microenvironment of fragmented collagen that impairs fibroblast function leading to abnormal collagen homeostasis with increased degradation and decreased production of collagen
the most striking histologic alteration of photodamaged dermis
Solar elastosis
- characterized by the replacement of **normal elastic fibers with a disordered mass of elastotic material **(ie, degraded elastic fibers, tropoelastin, and fibrillin) that is localized near the dermal–epidermal junction
Elderly men commonly have a drop in the density of chest, axillary, and pubic hair, but an increase of hair in other body sites is noted where?
nostrils, external auditory meatus, and eyebrows
Elderly women typically experience a new growth of coarse hair on the chin and upper lip, likely resulting from the unopposed influence of testosterone secondary to falling estrogen levels.
age-related thinning of hair
Senescent alopecia
androgenetic alopecia (or male pattern hair loss) is a distinct entity that can occur at an earlier age and results from the effect of dihydrotestosterone on hair follicles
T/F
Both the number and output of eccrine glands decline with age
TRUE
The resulting decrease in spontaneous sweating renders the elderly more vulnerable to heat stroke.
T/F
size and function of apocrine glandsare reduced in older skin
True
Although the size and number of sebaceous glands appear constant, there is a drop of sebum production that is likely associated with hormonal changes
T/F
With aging, tactile thresholds are decreased.
FALSE
- tactile thresholds are increased
- The decrease in the size and density of Pacinian and Meissner corpuscles may account for this finding
- There is also an increase in thermal pain thresholds in the elderly
- An age-associated decline in the spatial acuity (ability to discriminate between 2 points, light touch, and vibration) of the skin also occurs
T/F
Senile lentigines and seborrheic keratoses have no malignant potential and do not require therapy beyond cosmetic reasons
TRUE
- Unlike senile lentigines, the development of seborrheic keratoses is independent of UV exposure and is likely a result of impaired focal epidermal homeostasis resulting in the clonal expansion of melanocytes and keratinocytes
this regulator of melanocyte function has been implicated in the development of seborrheic keratosis
keratinocyte-derived endothelin-1
small circular or oval red papules resulting from the proliferation of blood vessels that tend to increase in size and number with age and may bleed with minor trauma
Senile/ cherry angiomas
nature of sun exposure in SCC and AK
Squamous cell cancer and its precursor lesion, actinic keratosis, are associated with** habitual sun exposure**
nature of sun exposure in BCC and Melanoma
basal cell cancer and malignant melanoma correlate with a history of habitual or intense intermittent sun exposure
clinical characteristics of Merkel cell carcinoma have been summarized in an acronym: AEIOU
- asymptomatic/ lack of tenderness,
- expanding rapidly,
- immune compromised,
- older than 50 years, and
- UV-exposed site on a person of fair skin
cancer of the inner lining of blood vessels, most commonly occurs in the elderly
Angiosarcoma
- It can affect any area of the body, but the majority present on the** head and neck**
- Rapidly proliferating and invasive anaplastic cells are characteristic of angiosarcoma
- aggressive and highly metastatic cancer is associated with a high mortality and often leads to death within 2 years of initial diagnosis
diseases associated with xerosis
chronic renal failure, liver disorders, lower-leg atherosclerosis, autoimmune diseases, and hepatitis C virus infections
xerosis complicated by dermatitis and is characterized by dry, extremely pruritic, fissured skin with scales
Asteatotic eczema
- It typically presents in the elderly during the winter seasons and is often associated with low humidity in heated environments
most frequent site of herpes simplex virus infection in older individuals
vermilion border of the lip
recurrent formation of ecchymoses on the sun-exposed extensor surfaces of the arms or hands of elderly patients
SENILE PURPUR/ BATEMAN PURPURA
Age-related skin thinning and sun-induced damage of the connective tissue of the dermis results in inadequate support and increased fragility of the microvasculature.
